Leakage protection circuit, method and drive device to which it is applied

Abstract

The application provides a leakage protection circuit, a method and a driving device. The leakage protection circuit is used for a power supply line connected with a load, and the power supply line is sampled at intervals. The voltage of the sampled electric signal is detected to determine whether the voltage of an alternating input power supply is divided, and leakage protection is provided based on the determined result. The application samples the voltage in the power supply line at intervals and detects the voltage division to determine whether the connected alternating input power supply is divided. When it is determined that the voltage is divided, the power supply line is disconnected, and the leakage protection of the mis-touching human body and the load is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic circuit, in particular to a leakage protection circuit, method and applicable driving device. BACKGROUND

[0002] When people insert one end of the LED fluorescent tube into the fluorescent tube frame slot, they may focus on assembling the needle-like pin of the LED fluorescent tube and ignore the position of the hand-held tube. When one end of the fluorescent tube is inserted into the fluorescent tube frame slot, the fingers may touch the other end of the LED fluorescent tube which is not inserted into the fluorescent tube frame slot, thereby causing electric shock danger. SUMMARY

[0003] In view of the above-mentioned defects of the prior art, the purpose of the present application is to provide a leakage protection circuit, method and applicable driving device, which is used to solve the problem of electric shock caused by human operation of touching the wiring end of the electric shock device.

[0004] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present application provides a leakage protection circuit, which is used to electrically connect a power supply circuit of a load, interval sample the power supply circuit, detect the voltage of the sampled electric signal to determine whether the voltage of the alternating current input power supply is divided, and provide leakage protection based on the determined result.

[0005] In some embodiments of the first aspect of the present application, the leakage protection circuit comprises: a detection unit connected to the power supply circuit, used to output a sampling control signal based on the detection of the voltage of the power supply circuit; a sampling unit connected to the detection unit, used to obtain a sampling electric signal of the power supply circuit based on the received sampling control signal; and a control unit connected to the sampling unit, used to compare the voltage of the sampling electric signal with a preset power-off protection voltage threshold, and provide leakage protection based on the comparison result.

[0006] In some embodiments of the first aspect of the present application, the detection unit comprises a voltage limiting detection circuit module connected to the power supply circuit, used to detect the voltage of the power supply circuit and output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval.

[0007] In some embodiments of the first aspect of the present application, the detection unit further comprises a timing circuit module connected to the voltage limiting detection circuit module, used to limit time output of a second sampling control signal based on the first sampling control signal.

[0008] In some embodiments of the first aspect of the present application, the timing circuit module sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing is timed out.

[0009] In some embodiments of the first aspect of the application, the timing circuit module outputs a second sampling control signal during the duration of the first sampling control signal.

[0010] In some embodiments of the first aspect of the application, the interval is set based on a voltage variation period in the power supply line or according to a preset duration.

[0011] In some embodiments of the first aspect of the application, the control unit comprises: a comparison circuit module for comparing the voltage of the sampled electrical signal with a preset power-off protection voltage threshold and outputting a comparison result; a logic latch circuit module connected to the comparison circuit module for latching the comparison result and outputting a corresponding latch signal; wherein the latch signal is used to represent the leakage protection control signal of the leakage protection circuit.

[0012] In some embodiments of the first aspect of the application, the control unit further comprises: a switch circuit module connected to the logic latch circuit module for controlling the power supply line to be turned on or disconnected based on the latch signal.

[0013] In some embodiments of the first aspect of the application, the logic latch circuit module is reset based on the leakage protection circuit being in an under-voltage state.

[0014] In some embodiments of the first aspect of the application, the interval sampling of the power supply line is stopped when the power supply line is controlled to be turned on.

[0015] In some embodiments of the first aspect of the application, the control unit is further connected to a detection unit for controlling the detection unit to stop outputting the sampling control signal while controlling the power supply line to be turned on.

[0016] In some embodiments of the first aspect of the application, the leakage protection circuit is an LED leakage protection circuit electrically connected to the power supply line of an LED load, and outputs a leakage protection control signal based on the determined comparison result so that the LED driving circuit electrically connected thereto gives a corresponding leakage protection response based on the leakage protection control signal.

[0017] The second aspect of the application provides a chip comprising: a plurality of pins, wherein at least one pin is electrically connected to the power supply line of a load; a leakage protection circuit connected to the pins for interval sampling of the power supply line, detecting the voltage of the sampled electrical signal to determine whether the voltage of the alternating input power supply is divided, and providing leakage protection based on the determined result.

[0018] In some embodiments of the second aspect of the application, the leakage protection circuit comprises: a detection unit connected to the power supply line, configured to output a sampling control signal based on detection of voltage of the power supply line; a sampling unit connected to the detection unit, configured to obtain a sampled electrical signal of the power supply line based on the received sampling control signal; and a control unit connected to the sampling unit, configured to compare voltage of the sampled electrical signal with a preset power-off protection voltage threshold, and provide leakage protection based on the comparison result.

[0019] In some embodiments of the second aspect of the application, the detection unit comprises a voltage limiting detection circuit module connected to the power supply line, configured to output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval.

[0020] In some embodiments of the second aspect of the application, the detection unit further comprises a timing circuit module connected to the voltage limiting detection circuit module, configured to output a second sampling control signal based on the first sampling control signal.

[0021] In some embodiments of the second aspect of the application, the timing circuit module sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing expires.

[0022] In some embodiments of the second aspect of the application, the timing circuit module outputs the second sampling control signal within a duration of the first sampling control signal.

[0023] In some embodiments of the second aspect of the application, the interval is set based on a voltage variation period in the power supply line, or according to a preset time length.

[0024] In some embodiments of the second aspect of the application, the control unit comprises: a comparison circuit module configured to compare voltage of the sampled electrical signal with a preset power-off protection voltage threshold and output a comparison result; and a logic latch circuit module connected to the comparison circuit module, configured to latch the comparison result and output a corresponding latch signal; wherein the latch signal is used to represent a leakage protection control signal of the leakage protection circuit.

[0025] In some embodiments of the second aspect of the application, the control unit further comprises a switch circuit module connected to the logic latch circuit module, configured to control the power supply line to be turned on or turned off based on the latch signal.

[0026] In some embodiments of the second aspect of the application, the logic latch circuit module is reset based on the leakage protection circuit being in an underpower state.

[0027] In some embodiments of the second aspect of the application, the leakage protection circuit outputs a leakage protection control signal based on the determined result; and the chip further comprises a pin for outputting the leakage protection control signal, so that a driving circuit connected to the pin gives a corresponding leakage protection response based on the leakage protection control signal.

[0028] In some embodiments of the second aspect of the application, the leakage protection circuit stops the interval sampling of the power supply line when the control of the power supply line is turned on.

[0029] In some embodiments of the second aspect of the application, the control unit is further connected to a detection unit, and is configured to control the detection unit to stop outputting the sampling control signal when the control of the power supply line is turned on.

[0030] In some embodiments of the second aspect of the application, the leakage protection circuit is an LED leakage protection circuit, and the power supply line of an LED load is electrically connected to the pin.

[0031] The third aspect of the application provides a driving device, comprising: a rectifier circuit configured to rectify an input alternating current and provide a power supply line for a load; a leakage protection circuit connected to the rectifier circuit, configured to perform interval sampling on the power supply line, detect a voltage of a sampled electrical signal to determine whether a voltage of an alternating current input power supply is divided, and provide leakage protection based on a determined result; and a driving circuit connected to the leakage protection circuit, configured to supply power to the load based on a current rectified by the rectifier circuit.

[0032] In some embodiments of the third aspect of the application, the leakage protection circuit comprises: a detection unit connected to the power supply line, configured to output a sampling control signal based on a detection of a voltage of the power supply line; a sampling unit connected to the detection unit, configured to obtain a sampled electrical signal of the power supply line based on the received sampling control signal; and a control unit connected to the sampling unit, configured to compare a voltage of the sampled electrical signal with a preset leakage protection voltage threshold, and provide leakage protection based on a comparison result.

[0033] In some embodiments of the third aspect of the application, the detection unit comprises a voltage limiting detection circuit module connected to the power supply line, configured to detect a voltage of the power supply line, and output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval.

[0034] In some embodiments of the third aspect of the application, the detection unit further comprises a timing circuit module connected to the voltage limiting detection circuit module, configured to output a second sampling control signal based on the first sampling control signal.

[0035] In some embodiments of the third aspect of the application, the timing circuit module sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing expires.

[0036] In some embodiments of the third aspect of the application, the timing circuit module outputs the second sampling control signal within a duration of the first sampling control signal.

[0037] In some embodiments of the third aspect of the application, the interval is set based on a voltage variation period in the power supply line, or according to a preset duration.

[0038] In some embodiments of the third aspect of the application, the control unit comprises: a comparison circuit module configured to compare a voltage of the sampled electrical signal with a preset power-off protection voltage threshold and output a comparison result; and a logic latch circuit module connected to the comparison circuit module, configured to latch the comparison result and output a corresponding latch signal; wherein the latch signal is used to represent a leakage protection control signal of the leakage protection circuit.

[0039] In some embodiments of the third aspect of the application, the control unit further comprises: a switch circuit module connected to the logic latch circuit module, configured to control the power supply line to be turned on or turned off based on the latch signal.

[0040] In some embodiments of the third aspect of the application, the logic latch circuit module is reset based on the leakage protection circuit being in an under-voltage state.

[0041] In some embodiments of the third aspect of the application, the leakage protection circuit outputs a leakage protection control signal to a driving circuit; and the driving circuit gives a corresponding leakage protection response based on the leakage protection control signal.

[0042] In some embodiments of the third aspect of the application, the driving circuit comprises an enable control unit, which gives a corresponding leakage protection response based on the leakage protection control signal when the leakage protection circuit outputs the leakage protection control signal.

[0043] In some embodiments of the third aspect of the application, the leakage protection circuit stops interval sampling of the power supply line when the power supply line is controlled to be turned on.

[0044] In some embodiments of the third aspect of the application, the control unit is further connected to a detection unit, and is configured to control the detection unit to stop outputting the sampling control signal when the power supply line is controlled to be turned on.

[0045] In some embodiments of the third aspect of the application, the driving device is an LED driving device.

[0046] The fourth aspect of the application provides a driving chip, comprising: a plurality of pins, wherein at least one pin is used to access a power supply line of a load to form a power supply loop with the chip; a leakage protection circuit connected to the pin, used to sample the power supply line at intervals, detect the voltage of the sampled electrical signal to determine whether the voltage of an alternating current input power supply is divided, and provide leakage protection based on the determined result; and a driving circuit connected to the leakage protection circuit, used to provide constant current power supply to the load based on the current rectified by a rectifier circuit.

[0047] In some embodiments of the fourth aspect of the application, the leakage protection circuit comprises: a detection unit connected to the power supply line, used to output a sampling control signal based on the detection of the voltage of the power supply line; a sampling unit connected to the detection unit, used to obtain a sampling electrical signal of the power supply line based on the received sampling control signal; and a control unit connected to the sampling unit, used to compare the voltage of the sampling electrical signal with a preset power-off protection voltage threshold, and provide leakage protection based on the comparison result.

[0048] In some embodiments of the fourth aspect of the application, the detection unit comprises a voltage limiting detection circuit module connected to the power supply line, used to detect the voltage of the power supply line, and output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval.

[0049] In some embodiments of the fourth aspect of the application, the detection unit further comprises a timing circuit module connected to the voltage limiting detection circuit module, used to output a second sampling control signal based on the first sampling control signal.

[0050] In some embodiments of the fourth aspect of the application, the timing circuit module sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing expires.

[0051] In some embodiments of the fourth aspect of the application, the timing circuit module outputs the second sampling control signal within the duration of the first sampling control signal.

[0052] In some embodiments of the fourth aspect of the application, the interval is set based on the voltage variation period in the power supply line, or according to a preset time length.

[0053] In some embodiments of the fourth aspect of the present application, the control unit comprises: a comparison circuit module configured to compare the voltage of the sampled electrical signal with a preset power-off protection voltage threshold and output a comparison result; a logic latch circuit module connected to the comparison circuit module and configured to latch the comparison result and output a corresponding latched signal; wherein the latched signal is used to represent the leakage protection control signal of the leakage protection circuit.

[0054] In some embodiments of the fourth aspect of the present application, the control unit further comprises: a switch circuit module connected to the logic latch circuit module and configured to control the power supply circuit to be turned on or turned off based on the latched signal.

[0055] In some embodiments of the fourth aspect of the present application, the logic latch circuit module is reset based on the leakage protection circuit being in an under-voltage state.

[0056] In some embodiments of the fourth aspect of the present application, the leakage protection circuit outputs a leakage protection control signal to a driving circuit; and the driving circuit gives a corresponding leakage protection response based on the leakage protection control signal.

[0057] In some embodiments of the fourth aspect of the present application, the driving circuit comprises an enable control unit, which gives a corresponding leakage protection response based on the leakage protection control signal when the leakage protection circuit outputs the leakage protection control signal.

[0058] In some embodiments of the fourth aspect of the present application, the leakage protection circuit stops the interval sampling of the power supply circuit when the power supply circuit is controlled to be turned on.

[0059] In some embodiments of the fourth aspect of the present application, the control unit is further connected to a detection unit and configured to control the detection unit to stop outputting the sampling control signal while controlling the power supply circuit to be turned on.

[0060] In some embodiments of the fourth aspect of the present application, the driving chip is an LED driving chip.

[0061] The fifth aspect of the present application provides a leakage protection method, comprising: interval sampling a power supply circuit of a load; detecting the voltage of the sampled electrical signal to determine whether the voltage of an AC input source is divided; and providing leakage protection based on the detection result.

[0062] In some embodiments of the fifth aspect of the present application, the interval sampling of the power supply circuit comprises: voltage limiting detection of the voltage of the power supply circuit; and obtaining the sampled electrical signal of the power supply circuit based on the result of the voltage limiting detection.

[0063] In some embodiments of the fifth aspect of the present application, the way of obtaining the sampled electrical signal of the power supply line based on the result of the voltage limiting detection comprises: collecting the sampled electrical signal on the power supply line within the voltage limiting interval at intervals of a preset detection timing.

[0064] In some embodiments of the fifth aspect of the present application, the interval is set based on a voltage variation period in the power supply line or according to a preset time length.

[0065] In some embodiments of the fifth aspect of the present application, the way of detecting the voltage of the sampled electrical signal comprises: comparing the voltage of the sampled electrical signal with a preset power-off protection voltage threshold, and determining whether the voltage of the AC input source is divided based on the comparison result.

[0066] In some embodiments of the fifth aspect of the present application, the way of providing the electric leakage protection based on the detection result comprises: when the detection result is that the voltage of the AC input source is not divided, controlling the power supply line to be turned on; when the detection result is that the voltage of the AC input source is divided, controlling the power supply line to be turned off; or when the detection result is that the voltage of the AC input source is not divided, controlling the driving circuit to supply power to the load; and when the detection result is that the voltage of the AC input source is divided, controlling the driving circuit to give an electric leakage protection response.

[0067] In some embodiments of the fifth aspect of the present application, the method further comprises the step of stopping the interval sampling of the power supply line when the power supply line is controlled to be turned on.

[0068] In the sixth aspect of the present application, a driving method is provided, comprising: providing a power supply line for a load after rectifying an accessed AC power; interval sampling the power supply line; detecting the voltage of the sampled electrical signal to determine whether the voltage of the AC input source is divided; providing electric leakage protection based on the detection result; and supplying power to the load on the power supply line when it is confirmed that the electric leakage protection is not needed.

[0069] In some embodiments of the sixth aspect of the present application, the way of interval sampling the power supply line comprises: voltage limiting detection of the voltage of the power supply line; and obtaining the sampled electrical signal of the power supply line based on the result of the voltage limiting detection.

[0070] In some embodiments of the sixth aspect of the present application, the way of obtaining the sampled electrical signal of the power supply line based on the result of the voltage limiting detection comprises: collecting the sampled electrical signal on the power supply line within the voltage limiting interval at intervals of a preset detection timing.

[0071] In some embodiments of the sixth aspect of the present application, the interval is set based on a voltage variation period in the power supply line or according to a preset time length.

[0072] In some embodiments of the sixth aspect of the present application, the way of detecting the voltage of the sampled electrical signal comprises comparing the voltage of the sampled electrical signal with a preset power-off protection voltage threshold and determining whether the voltage of the AC input source is divided based on the comparison result.

[0073] In some embodiments of the sixth aspect of the present application, the way of providing the electric leakage protection based on the detected result comprises controlling the power supply line to be turned on when the detected result is that the voltage of the AC input source is not divided, controlling the power supply line to be turned off when the detected result is that the voltage of the AC input source is divided, or controlling the driving circuit to supply power to the load when the detected result is that the voltage of the AC input source is not divided, and controlling the driving circuit to give an electric leakage protection response when the detected result is that the voltage of the AC input source is divided.

[0074] In some embodiments of the sixth aspect of the present application, the method further comprises the step of stopping the interval sampling of the power supply line when the power supply line is controlled to be turned on.

[0075] As described above, the electric leakage protection circuit, method and driving device of the present application have the following beneficial effects: the voltage in the power supply line is sampled at intervals and divided to determine whether the connected AC input power source is divided, and when it is determined that the voltage is divided, the power supply line is turned off, thereby achieving the electric leakage protection of the mis-touch human body and load. BRIEF DESCRIPTION OF DRAWINGS

[0076] Figure 1 A schematic diagram showing the connection relationship of the LED daylight lamp connected to the AC input power source.

[0077] Figure 2 A schematic diagram showing the structural framework of the electric leakage protection circuit of the present application in an embodiment.

[0078] Figure 3 A schematic diagram showing the structure of the voltage limiting detection circuit module in the electric leakage protection circuit of the present application in an embodiment.

[0079] Figure 4 A timing sequence diagram showing the voltage limiting detection circuit module and the timing circuit module of the electric leakage protection circuit of the present application in an embodiment using the first sampling control signal and the second sampling control signal waveforms.

[0080] Figure 5A timing circuit module of the leakage protection circuit in an embodiment of the present application is shown in a structural schematic diagram.

[0081] Figure 6 The relationship between the second sampling control signal and the first sampling control signal outputted by the timing circuit module in an embodiment of the present application is shown in a waveform schematic diagram.

[0082] Figure 7 A timing circuit module of the leakage protection circuit in an embodiment of the present application is shown in a structural schematic diagram.

[0083] Figure 8 A leakage protection circuit in an embodiment of the present application is shown in a structural schematic diagram.

[0084] Figure 9 The relationship between the voltage of the sampled electrical signal and the power-off protection voltage threshold when the leakage protection circuit detects a human body voltage division or no human body voltage division is shown in a waveform schematic diagram.

[0085] Figure 10 A leakage protection circuit in another embodiment of the present application is shown in a structural schematic diagram.

[0086] Figure 11 A chip containing a leakage protection circuit in an embodiment of the present application is shown in a packaging structural schematic diagram.

[0087] Figure 12 A frame structure of a driving device in an embodiment of the present application is shown in a structural schematic diagram.

[0088] Figure 13 A circuit structure of a driving device in an embodiment of the present application is shown in a structural schematic diagram.

[0089] Figure 14 A flowchart of a leakage protection method in an embodiment of the present application is shown.

[0090] Figure 15 A flowchart of a driving method in an embodiment of the present application is shown.

[0091] Figure 16 A structural schematic diagram of a leakage protection circuit and a driving circuit is shown.

[0092] Figure 17 Another structural schematic diagram of a leakage protection circuit and a driving circuit is shown. DETAILED DESCRIPTION

[0093] The embodiments of the present application are illustrated by specific working examples below, and other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure.

[0094] It should be noted that the structure, proportion, size, etc. shown in the drawings of the present specification are only used to cooperate with the content disclosed in the specification, so that those skilled in the art can understand and read, and are not used to limit the conditions that can be implemented by the present application, so they do not have technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" in the present specification are only for the convenience of clear description, and are not used to limit the scope of the present application, and the change or adjustment of the relative relationship is also considered as the scope of the present application without substantially changing the technical content.

[0095] The leakage caused by human operation usually occurs in the assembly operation of the load. As shown in the connection relationship of the LED daylight lamp and the driving device connected to the AC input power supply, Figure 1 The driving device and the LED load are built-in in the LED daylight lamp tube, and the two ends of the LED daylight lamp tube are connected to the phase line slot and the neutral line slot (i.e. the live end and the zero end) of the AC input power supply. In the assembly process of the above connection relationship, when one end of the LED daylight lamp tube is inserted into the daylight lamp tube frame slot, people may focus on assembling the needle-shaped pin of the LED daylight lamp and ignore the position of the handheld lamp tube. When one end of the daylight lamp is inserted into the daylight lamp tube frame slot, the other end of the LED daylight lamp which is not inserted into the daylight lamp tube frame slot is mistakenly touched by the finger, thereby causing the risk of electric shock.

[0096] To solve the leakage problem existing in the assembly and connection mode of the LED load and the driving device, and to extend to other similar electrical appliance assembly processes, the present application provides a leakage protection circuit which is connected to the power supply circuit of the load, samples the power supply circuit at intervals, detects the voltage of the sampled electric signal to determine whether the voltage of the AC input power supply is divided, and controls the conduction or disconnection of the power supply circuit based on the determined result. Taking the LED load as an example, the leakage protection circuit is an LED leakage protection circuit and provides leakage protection for the connecting operator and the LED load when the LED load is connected to the power supply circuit. The leakage protection circuit provided by the present application can be configured as an LED leakage protection circuit on the power supply circuit of the LED load. The power supply circuit mainly includes a circuit for converting the rectified current into a load driving current after rectifying the AC current. The power supply circuit not only has a conductor loop for returning the current from the rectifier circuit to the ground, but also includes an electrical device provided on the conductor loop and used for supplying power to the load, which includes the leakage protection circuit.

[0097] In this embodiment, the leakage protection circuit can be built in the driving device of the electrical appliance. The driving device can convert the AC power provided by the AC input power source into power for the load. For example, the LED driving device provides power for the LED load according to the working voltage of the LED load. The leakage protection circuit of the LED is built in the LED driving device. For example, the leakage protection circuit of the LED is configured in the LED driving device and is electrically connected to the power supply circuit at the back end of the rectifier circuit. When the AC input power source is not connected to both ends of the LED fluorescent lamp, the leakage protection circuit makes the entire power supply circuit unable to form a power supply circuit for the load. When the AC input power source is connected for a short period of time, the leakage protection circuit detects whether leakage occurs. If no leakage occurs, the power supply circuit is turned on to make the load work. Otherwise, the power supply circuit is maintained in a state where it cannot form a power supply circuit for the load.

[0098] In the above example, the leakage protection circuit samples the electrical signal of the rectified power supply circuit at intervals and detects whether the voltage of the AC input power source received by the electrical appliance is divided according to the voltage of the sampled electrical signal. When it is determined based on the detection result that the voltage of the AC input power source is divided, leakage protection is provided, thereby effectively preventing the risk of leakage when a human body is accidentally touched. When it is determined based on the detection result that the voltage of the AC input power source is not divided, the power supply circuit is controlled to be turned on, thereby providing working power for the load.

[0099] In this embodiment, the sampling interval of the leakage protection circuit can be set based on the voltage variation period in the power supply circuit. For example, the electrical signal is sampled at the voltage peak or valley in each or every other voltage variation period after rectification, or the electrical signal is sampled in a fixed voltage region between the voltage peak and valley in each or every other voltage variation period after rectification. To ensure that a human body will not be injured by continuous electric shock when accidentally touched, the sampling interval is in the order of milliseconds or even microseconds. For example, the sampling interval can be every half voltage variation period, every voltage variation period, or every multiple voltage variation periods. The sampling interval can be realized by the circuit structure designed by the leakage protection circuit using the voltage variation period. Alternatively, the sampling interval is set according to a pre-set time period. For example, the leakage protection circuit includes a capacitor and a resistor, and the sampling interval is determined by the charging time of the capacitor. The technician can design the corresponding sampling interval by configuring the resistor. The resistor can be an adjustable resistor or a fixed resistor.

[0100] In this case, the voltage detection method of the leakage protection circuit can determine whether the voltage of the AC input power is divided by comparing the sampled voltage with the preset reference voltage corresponding to the sampling time, so as to determine whether the power supply line where the load is located is turned on. For example, the leakage protection circuit starts timing of the sampling interval by detecting the voltage zero point on the power supply line, samples the electrical signal on the power supply line when the timing reaches, and determines the voltage threshold at the timing reaching time according to the voltage variation period of the power supply line, compares the sampled electrical signal voltage with the voltage threshold, so as to determine whether the voltage of the AC input power is divided. When it is determined that the voltage is divided, the leakage protection circuit can output a leakage protection control signal to control other circuits on the power supply line to temporarily suspend operation, or disconnect the connected power supply line. The other circuits include but are not limited to: driving circuit, filtering circuit, etc. Taking the leakage protection circuit of the LED load as an example, the LED leakage protection circuit is electrically connected with the power supply line of the LED load, and the LED leakage protection circuit outputs a leakage protection control signal based on the determined comparison result, so that the LED driving circuit electrically connected therewith gives a corresponding leakage protection response based on the leakage protection control signal. For example, the driving circuit includes an enable control unit, the controlled end of which is connected to the output end of the leakage protection circuit and the switching device or logic device in the driving circuit, when the enable control unit receives the leakage protection control signal, the switching device in the driving circuit is controlled to be disconnected, so that the energy converted by the driving circuit cannot be provided to the load, until the leakage protection control signal is disabled and the driving circuit enters the conduction state, at this time the driving circuit can perform driving operation. For another example, the driving circuit includes another enable control unit, the controlled end of which is connected to the output end of the leakage protection circuit, the input end is connected to the power supply end of the driving circuit, and the output end is grounded; when the leakage protection circuit outputs the leakage protection control signal, the enable control unit gives a corresponding leakage protection response based on the leakage protection control signal, that is, the power supply end is grounded so that the active device in the driving circuit cannot reach its working voltage.

[0101] In this case, the leakage protection circuit samples the electrical signal voltage according to the interval set according to the voltage variation period, and can determine whether the voltage of the AC input power is divided by comparing the electrical signal voltage with the preset power-off protection voltage threshold. For this purpose, please refer to Figure 2 , which shows a structural framework schematic diagram of the leakage protection circuit in an embodiment. As shown in the figure, the leakage protection circuit includes a detection unit 11, a sampling unit 12 and a control unit 13.

[0102] The detection unit 11 is connected to the power supply line, and is configured to output a sampling control signal based on detection of the voltage of the power supply line. Here, the detection unit 11 can detect the voltage change on the power supply line in real time, and determine that the sampling interval is reached and output the sampling control signal when the voltage change is detected to be a preset reference voltage value. The preset reference voltage value can correspond to any voltage value in the voltage change period, such as the peak value, the valley value, the intermediate value, etc. The sampling control signal is used to control the sampling unit to perform sampling operation.

[0103] In some embodiments, the detection unit includes a voltage limiting detection circuit module connected to the power supply line, configured to detect the voltage of the power supply line, and output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval. The voltage limiting interval is intercepted within the voltage change range of the power supply line. For example, the voltage limiting interval is [V1, V2], where 0≤V1<V2<Vmax, and Vmax is the maximum value of the voltage change range.

[0104] To achieve the above-mentioned voltage limiting detection, the voltage limiting detection circuit module includes at least one comparator configured to compare whether the voltage on the power supply line reaches within the preset voltage limiting interval. The comparator is configured to provide a boundary threshold of the voltage limiting interval. The comparator includes but is not limited to a hysteresis comparator, a window comparator, a zero-crossing comparator, etc. In some embodiments, the voltage limiting detection circuit module is a valley bottom detection circuit designed based on sinusoidal change. For example, please refer to Figure 3 which shows a structural schematic diagram of the voltage limiting detection circuit module. As shown in the figure, the voltage limiting detection circuit module includes a zero-crossing comparator, and the negative input end of the zero-crossing comparator is connected to the boundary threshold of the voltage limiting interval, and the positive input end is directly or through a circuit including a sampling resistor connected to the power supply line. When the voltage change of the power supply line is less than the boundary threshold, the first sampling control signal is output. The boundary threshold is greater than zero, so that the first sampling control signal maintains an effective duration, while tolerating the false triggering or false non-triggering caused by the voltage instability of the power supply line. The sampling unit can sample the electric signal according to the rising edge or falling edge of the first sampling control signal, or continuously sample the electric signal during the effective period of the first sampling control signal. The sampling unit controlled based on the first sampling control signal performs sampling action once in each voltage change period.

[0105] In some embodiments, the detection unit further comprises a timing circuit module. The timing circuit module is connected to the voltage-limiting detection circuit module, and is configured to output a second sampling control signal based on the first sampling control signal. The timing circuit module outputs the second sampling control signal based on a rising edge of the first sampling control signal, and the sampling unit is enabled to sample based on the second sampling control signal. The duration of the second sampling control signal can be regarded as the duration of the sampling unit to allow sampling. Limiting the sampling duration can effectively prevent the false-on operation caused by the jitter of the sampled electrical signal. For example, refer to Figure 4 FIG. 3 shows a timing diagram of the voltage-limiting detection circuit module and the timing circuit module represented by the waveforms of the first sampling control signal and the second sampling control signal. The timing circuit module outputs the second sampling control signal based on a rising edge of the first sampling control signal, and counts the duration of the second sampling control signal. During the counted duration, the sampling unit samples the electrical signal. In order to prevent the false-on operation caused by the jitter of the sampled electrical signal, the timing circuit module outputs the second sampling control signal within the duration of the first sampling control signal, i.e., the duration of the second sampling control signal is less than that of the first sampling control signal. The sampling unit samples the electrical signal based on the second sampling control signal.

[0106] In some specific examples, the timing circuit module includes a clock signal generator, a counter Counter 1, a logic device group, and a switch, etc. The switch is connected to the voltage-limiting detection circuit module, and is connected to the control terminal of the counter Counter 1. The input terminal of the counter Counter 1 is connected to the clock signal generator, and the output terminal of the counter Counter 1 is connected to the logic device group. The switch is turned on and off based on the first sampling control signal. When the switch is turned on, the counter Counter 1 starts counting the received clock signal. Before the number of pulses of the counted clock signal reaches a preset value, the logic device group outputs the second sampling control signal. When the number of pulses counted by the counter Counter 1 reaches the count value, the logic device group is controlled not to output the second sampling control signal until the next first sampling control signal arrives.

[0107] In some specific examples, refer to Figure 5, which shows a structural schematic diagram of the timing circuit module in an embodiment. As shown in the figure, the timing circuit module comprises a capacitor, a capacitor charging controller, a capacitor discharging controller, two comparators and a logic device group, etc. Among them, the capacitor discharging controller is connected between the two ends of the capacitor; the control end of the capacitor charging controller receives a first sampling control signal, the input end is connected to a constant voltage, and the output end is connected to the capacitor; the capacitor is directly or through a resistor connected to the ground; the input end of the capacitor is also connected to comparators A1 and A2; among them, the other input end of comparator A1 is connected to a reference voltage Vref 1, and the other input end of comparator A2 is connected to a reference voltage Vref 2; the output ends of comparators A1 and A2 are both connected to the logic device group, and the logic device group outputs the second sampling control signal. Among them, the capacitor charging controller and the capacitor discharging controller can both be controlled switches, such as MOS tubes. The reference voltage Vref 1 is close to 0V, and Vref 2 is a voltage value higher than Vref 1. Through the design of the technical personnel, the time length of the capacitor voltage from Vref 1 to Vref 2 is less than the time length of the first sampling control signal. Initially, the capacitor discharging controller shorts the capacitor and the capacitor charging controller is disconnected, so that the capacitor is in a zero charge state, and correspondingly, the comparator A1 outputs a low level; when the capacitor charging controller receives the first sampling control signal, the capacitor charging controller is turned on and the capacitor discharging controller is disconnected, so that the capacitor is charged, when the capacitor voltage is higher than the reference voltage Vref, the comparator A1 outputs a high level and the comparator A2 still outputs a low level, and the logic device group outputs the second sampling control signal according to the preset logic configuration when the comparator A1 outputs a high level and the comparator A2 outputs a low level; when the capacitor voltage reaches Vref 2, the comparator A2 jumps to a high level, and the logic device group does not output the second sampling control signal according to the logic configuration when the comparators A1 and A2 both output a high level, and controls the capacitor charging controller to be disconnected to make the capacitor no longer charge, and controls the capacitor discharging controller to be turned on to discharge the capacitor charge, until the next first sampling control signal arrives.

[0108] In still some embodiments, the timing circuit module also sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing expires. Please refer to Figure 6 , which shows a waveform schematic diagram of the relationship between the second sampling control signal and the first sampling control signal output by the timing circuit module. As shown in the figure, among them, the detection timing can make the timing circuit module not output the second sampling control signal based on the first sampling control signal within the time interval T2 of at least one first sampling control signal.

[0109] In some specific examples, the timing circuit module comprises a plurality of counters, one of which, Counter 1, is used to count the duration of the second sampling control signal, and another, Counter 2, is used to count the detection timing. The timing circuit module further comprises a clock signal generator, a switch and a logic device group. The switch is turned on and off based on the first sampling control signal, and when turned on, it enables the counter Counter 1 to start counting the received clock signal. Before the number of pulses of the clock signal counted by the counter Counter 1 reaches a preset value, the logic device group outputs the second sampling control signal. When the number of pulses counted by the counter Counter 1 reaches the count value, the control logic device group stops outputting the second sampling control signal, at which time the counter Counter 2 starts counting the number of pulses of the received clock signal. When the counter Counter 2 reaches its count value, i.e. the detection timing is over, it controls the logic device group to output the second sampling control signal.

[0110] In yet some specific examples, please refer to Figure 7The timing circuit module is shown in a structural schematic diagram of another embodiment. As shown in the figure, the timing circuit module can include a plurality of capacitors, each of which is configured with a capacitor charging controller and a capacitor discharging controller, a plurality of comparators, and a logic device group, etc. Among them, the configured capacitor discharging controller is connected between the two ends of the corresponding capacitor; the control end of the configured capacitor charging controller receives a first sampling control signal, the input end is connected to a constant voltage, and the output end is connected to the corresponding capacitor; each of the capacitors is directly or through a resistor connected to ground; the input end of one of the capacitors C1 is also connected to comparators A1 and A2; among them, the other input end of comparator A1 is connected to reference voltage Vref 1, and the other input end of comparator A2 is connected to reference voltage Vref 2; comparator A3 is connected to another capacitor C2 and connected to reference voltage Vref 3; the output ends of comparators A1, A2 and A3 are all connected to a logic device group, and the logic device group outputs the second sampling control signal. Among them, the reference voltage Vref 1 is close to 0V, and Vref 2 is a voltage value higher than Vref 1. Through the design of the technician, the time length of the capacitor C1 voltage rising from Vref 1 to Vref 2 is less than the time length of the first sampling control signal; and the time length of the capacitor C2 voltage reaching Vref 3 from the initial value (such as 0v) is greater than the time length of one first sampling control signal. Initially, the capacitor discharging controller CDC1 shorts the capacitor C1 and the capacitor charging controller CCC1 is disconnected, so that the capacitor C1 is in a zero charge state, at the same time, the capacitor discharging controller CDC2 connected with the capacitor C2 is disconnected and the capacitor charging controller CCC2 is turned on, so that the capacitor C2 is in a state of storing charge; correspondingly, the comparators A1 and A2 output low level, and the comparator A3 outputs high level; when the capacitor charging controller CCC1 connected with the capacitor C1 receives the first sampling control signal, the capacitor charging controller CCC1 connected with the capacitor C1 is turned on and the capacitor discharging controller CDC1 is disconnected, so that the capacitor C1 is charged, when the voltage of the capacitor C1 is higher than the reference voltage Vref 1, the comparator A1 outputs high level and the comparator A2 still outputs low level, and the logic device group outputs the second sampling control signal according to the preset logic configuration when the comparators A1 and A3 output high level and the comparator A2 outputs low level. At this time, the capacitor discharging controller CDC2 and the capacitor charging controller CCC2 are controlled by the second sampling control signal to discharge the capacitor C2, and the comparator A3 outputs low level; however, when the capacitor C1 continues to charge and the voltage reaches Vref 2, the comparator A2 jumps to high level, and the logic device group no longer outputs the second sampling control signal according to the logic configuration when the comparators A1 and A2 both output high level and the comparator A3 outputs low level, and controls the capacitor charging controller CCC1 to be disconnected to stop charging the capacitor C1, and controls the capacitor discharging controller CDC1 to be turned on to discharge the capacitor C1.When the capacitor C1 discharges, the capacitor C2 capacitor charging controller CCC2 is turned on and the capacitor discharge controller CDC2 is turned off, so that the capacitor C2 is charged until the capacitor C2 voltage reaches Vref 3, the comparator A3 outputs high level, and the logic device group outputs the second sampling control signal according to the level change of the comparators A1 and A2 according to the logic configuration when the comparator A3 outputs high level.

[0111] It should be noted that the circuit structure provided by the timing circuit module is only an example and is not a limitation of the circuit structure of the timing circuit module in the present application. In fact, according to the design of the timing logic by the technician, other timing circuit modules containing comparators, logic device groups, capacitors can also be proposed; or timing circuit modules containing clock signal generators and counters. Herein, the design of the timing circuit module based on the above technical inspiration is regarded as a specific example of the present application. In addition, the devices in the above timing circuit module can be fixedly arranged in the leakage protection circuit. In order to facilitate the various types of alternating current cycles provided by different alternating current power supplies, the timing devices such as capacitors and their peripheral devices, or counters in the above timing circuit module can be selected by the technician according to the specific design needs. Based on the design of the above timing circuit module, an example is that the sampling unit in the leakage protection circuit samples the voltage of the electrical signal on the power supply line during receiving the second sampling control signal.

[0112] It should also be noted that the logic device group mentioned in any of the above examples can contain at least one logic device and be electrically connected by the logic device to realize the corresponding logic configuration according to the actual logic design needs. Among them, the logic device includes but is not limited to AND gate, OR gate, NAND gate, NOT gate, encoder, decoder, selector, etc.

[0113] The sampling unit is connected with the detection unit, and is used for acquiring a sampling electrical signal of the power supply line based on the received sampling control signal.

[0114] Please refer to Figure 8 , which shows the structure schematic diagram of the leakage protection circuit in an embodiment. As shown in the figure, the sampling unit 12 contains a controlled switch and a sampling resistor, wherein the control end of the controlled switch is connected with the output end of the detection unit, one access end of the controlled switch is connected with the power supply line, and the other access end is connected with the ground through the sampling resistor, and the sampling resistor is also connected with the control unit 13. Among them, the controlled switch includes but is not limited to any one of the following: triode (BJT), junction field effect transistor (JFET), depletion MOS power tube, and silicon controlled dimmer, etc. When the detection unit 11 outputs a sampling control signal, the controlled switch is turned on, and the control unit 13 acquires the voltage of the sampled electrical signal from the sampling resistor.

[0115] In a specific example, as shown in Figure 8 The controlled switch is a MOS power transistor in this example, the gate of the MOS power transistor is connected to the output of the timing circuit module, the drain of the MOS power transistor is connected to the power supply circuit, and the source of the MOS power transistor is connected to the sampling resistor. The MOS power transistor is turned on during the period when the first sampling control signal or the second sampling control signal is received, so that the control unit 13 obtains the sampled voltage, according to the timing circuit module provided above.

[0116] The control unit is configured to compare the voltage of the sampled electrical signal with a preset power-off protection voltage threshold, and provide leakage protection based on the comparison result.

[0117] In this case, the power-off protection voltage threshold preset by the control unit can be provided by a constant voltage circuit. The power-off protection voltage threshold can be designed based on the voltage drop affecting the sampling unit due to the body voltage division of alternating current. When the control unit determines that the sampled voltage is lower than the power-off protection voltage threshold, the power supply circuit can be disconnected or a leakage protection control signal can be output; otherwise, the power supply circuit of the power supply circuit is turned on to enable the load to work normally.

[0118] In an embodiment, the control unit comprises a comparison circuit module, a logic latch circuit module, and a switch circuit module. The comparison circuit module is configured to compare the voltage of the sampled electrical signal with a preset power-off protection voltage threshold and output a comparison result. The logic latch circuit module is connected to the comparison circuit module and is configured to latch the comparison result. The switch circuit module is connected to the logic latch circuit module and is configured to control the power supply circuit to be turned on or disconnected based on the latched signal.

[0119] Please refer to Figure 9 , which shows that the leakage protection circuit corresponds to Figure 8 When the load is connected to the power supply circuit and there is no artificial voltage division, the waveform of the voltage of the sampled electrical signal received by the comparison circuit module is shown in the leakage protection circuit. As shown in the figure, when the load is connected to the power supply circuit and there is no artificial error operation, the sampled voltage is higher than the power-off protection voltage threshold Vref; when the load is connected to the power supply circuit and there is an artificial error operation, the sampled voltage is lower than the power-off protection voltage threshold Vref due to the body voltage division. When the sampled voltage is higher than the power-off protection voltage threshold Vref, the comparison circuit module outputs a jump signal, the logic latch circuit module latches the jump signal and outputs a latched signal to the switch circuit module, and the switch circuit module controls the power supply circuit to be turned on; otherwise, the comparison circuit module does not output a jump signal, the logic latch circuit module does not output a latched signal, and the switch circuit module maintains the power supply circuit to be disconnected. In this way, the load and personal safety are protected.

[0120] In a specific example, the comparison circuit module comprises a comparator, and the switch circuit module comprises a controlled switch and a switch drive module. The negative input terminal of the comparator is connected to the power-off protection voltage threshold, and the positive input terminal of the comparator is connected to the input terminal of the logic latch circuit module. The output terminal of the logic latch circuit module is the output terminal of the detection unit. The switch circuit module takes the MOS power tube and the gate drive module as an example. The gate of the MOS power tube is connected to the output terminal of the comparator through the gate drive module, and the source and the drain are connected to the power supply circuit. When the load is normally connected to the power supply circuit, the comparator always outputs a high level, and the MOS power tube turns on the power supply circuit to make the load work normally. Please refer to Figure 8 which shows the structure of the leakage protection circuit in another embodiment. When the output of the comparison circuit module jumps from low level to high level, the logic latch circuit module latches the high level state. When the output of the comparison circuit module jumps from high level to low level, the logic latch circuit module latches the low level state. Initially, the logic latch circuit module is in the low level state, and the switch circuit module is disconnected from the power supply circuit based on the received low level state latch signal. When the output of the comparison circuit module jumps from low level to high level, the logic latch circuit module latches the high level state and outputs a high level state latch signal, and the switch circuit module is connected to the power supply circuit. Therefore, the latch signal is used to represent the leakage protection control signal of the leakage protection circuit.

[0121] Here, the MOS power tube in the controlled switch can also be replaced by any one of a transistor (BJT), a junction field effect transistor (JFET), a depletion MOS power tube, a silicon controlled dimmer, etc. The switch drive module is not necessarily a gate drive module, but can be adjusted according to actual design needs. For example, the switch circuit module comprises a MOS power tube and a source drive module, etc.

[0122] In some other embodiments, the output terminal of the logic latch circuit module is connected to other circuits (such as the drive circuit mentioned above) on the power supply circuit, so that the other circuits provide corresponding leakage protection based on the latch signal. Here, no further description is given.

[0123] It should be noted that the comparison relationship between the sampling electrical signal voltage and the power-off protection voltage threshold when there is a human body voltage division, and the comparison relationship between the sampling electrical signal voltage and the power-off protection voltage threshold when there is no human body voltage division shown in the above Figure 9 are related to the circuit structure of the sampling unit. When the circuit structure of the sampling unit is configured such that the sampled electrical signal voltage when there is a human body voltage division is higher than the sampled electrical signal voltage when there is no human body voltage division, the corresponding control unit should be based on the comparison relationship between the sampling electrical signal voltage and the power-off protection voltage threshold when there is a human body voltage division. Figure 9The opposite comparison result provides corresponding leakage protection. The circuit structure of the sampling unit can also be connected to the power supply line through a sampling resistor connected to one access end of a controlled switch and grounded to the other access end. This is not listed one by one here.

[0124] To prevent the logic latch circuit module from providing an incorrect latch signal during the restart operation after the user turns off the load, the logic latch circuit module needs to be reset to the initial low state when the load is powered off. In some specific examples, the logic latch circuit module is reset based on the leakage protection circuit being in an underpower state.

[0125] The underpower state is a state in which the power supply of the load cannot reach its working voltage due to external factors or electrical components on the power supply line during normal operation of the load, thereby causing the load to stop working. The underpower state of the leakage protection circuit can be caused by artificial power-off or by abnormality of internal (or external) electrical components of the leakage protection circuit. For example, situations that cause the leakage protection circuit to be in an underpower state include but are not limited to: the power-off state of the leakage protection circuit during power-off; and the state of the leakage protection circuit during which the power supply system cannot provide corresponding working voltage to the active devices in the leakage protection circuit.

[0126] The logic circuit module can reset its latched signal by detecting the underpower state of the leakage protection circuit. In one specific example, the reset end of the logic latch circuit module is connected to the power supply line, and when the power supply line is powered off, the leakage protection circuit is in an underpower state, and the corresponding reset end receives a reset valid signal. In another specific example, the reset end of the logic latch circuit module is connected to the under-voltage protection circuit for protecting the leakage protection circuit, and when the under-voltage protection circuit generates an underpower protection signal due to detection of the underpower state of the leakage protection circuit, the reset end of the logic latch circuit module takes the underpower protection signal as the reset valid signal. Thus, the reset operation of the logic latch circuit module is realized.

[0127] In addition, due to the logical latch circuit module, when the power supply line is connected, the detection unit and the sampling unit do not necessarily need to continuously provide the voltage of the electrical signal to continuously control the switch circuit unit to be turned on. Therefore, interval sampling of the power supply line is stopped when the power supply line is controlled to be turned on. The leakage protection circuit can add a control circuit module in the detection unit or the sampling unit to correspondingly stop detection or sampling. In some specific examples, the control unit is also connected with the detection unit to control the detection unit to stop outputting the sampling control signal when the power supply line is controlled to be turned on. For example, the timing circuit module in the detection unit is also connected with the output end of the logical latch circuit module in the control unit, and when the logical latch circuit module outputs a high-level state latch signal, the timing circuit module does not output the first sampling control signal or the second sampling control signal. In this way, the problem of false power-off of the load caused by unstable voltage of the alternating input power supply can be effectively prevented.

[0128] The working process of the leakage protection circuit will be described below with reference to the leakage protection circuit structure shown in Figure 10 When the load is connected to the power supply line, the voltage on the power supply line is acquired by the voltage limiting detection circuit module 111 in real time, and when the acquired voltage falls within the preset valley voltage interval, the first sampling control signal is output. The timing circuit module 112 outputs the second sampling control signal based on the first sampling control signal and starts to detect the timing. The second sampling control signal has a shorter duration than the first sampling control signal. The sampling unit 12 samples the voltage of the power supply line based on the second sampling control signal and provides the sampled voltage to the comparison circuit module 131 in the control unit 13 to compare the sampled voltage with the preset power-off protection voltage threshold. If the sampled voltage is lower than the power-off protection voltage threshold, it indicates that the alternating input power supply is artificially divided, the comparison circuit module 131 outputs a low-level signal, and the logical latch circuit module 132 controls the switch circuit module 133 to disconnect the power supply line based on the low-level signal. If the sampled voltage is higher than the power-off protection voltage threshold, it indicates that the load is normally connected to the power supply line, the comparison circuit module 131 outputs a high-level signal, the logical latch circuit module 132 outputs a high-level state latch signal based on the high-level signal, and controls the switch circuit module 133 to connect the power supply line.

[0129] During the period when the power supply line is not connected, the timing circuit module 112 does not output the second sampling control signal based on the first sampling control signal when the detection timing does not arrive, and only responds to the first sampling control signal when the detection timing is timed out. In addition, during the period when the power supply line is connected, the timing circuit module 112 is controlled to not output the second sampling control signal to disconnect the loop where the sampling resistor is located, thereby reducing the electrical loss of the leakage protection circuit.

[0130] The present application also provides a chip comprising a leakage protection circuit, which can be assembled in a power supply circuit for supplying power to a load. In some examples, the chip is assembled in a driving device. For example, the chip is assembled at the back end of a rectification circuit in a driving device. The driving device is exemplified by an LED driving device.

[0131] Referring to Figure 11 , which shows a schematic diagram of a packaging structure of a chip comprising a leakage protection circuit. As shown in the figure, the chip comprises a plurality of pins, at least one of which is used to access a power supply circuit of a load so that the power supply circuit forms a power supply loop via the chip. The pins include GND, DRAIN and HV. Among them, the HV pin is connected to the power supply circuit as the current input end of the chip, and the DRAIN and GND pins are connected to the power supply circuit as the ground loop of the power supply circuit. The leakage protection circuit detects the voltage of the sampled electrical signal by sampling the HV pin at intervals to determine whether the voltage of the alternating input power supply is divided, and controls the conduction or disconnection of the circuit between the DRAIN and GND pins based on the determined result, thereby realizing leakage protection. The number of pins of the chip is related to the integrated circuit module, for example, the chip comprises a leakage protection circuit, and the constant voltage power supply used by the leakage protection circuit can be shared with the constant voltage power supply in other circuits in the driving device or be separately configured and integrated in the chip. For the case of sharing the constant voltage power supply, the chip further comprises a pin for connecting to the constant voltage power supply.

[0132] In Figure 11 , the HV, DRAIN and GND pins are connected to the leakage protection circuit, wherein the HV pin is used to provide the voltage of the power supply circuit to the leakage protection circuit, and the DRAIN and GND pins are used to control the conduction or disconnection of the power supply circuit. The leakage protection circuit is used to sample the power supply circuit at intervals, detect the voltage of the sampled electrical signal to determine whether the voltage of the alternating input power supply is divided, and control the conduction or disconnection of the power supply circuit based on the determined result.

[0133] In other embodiments, according to the actual design requirements of the peripheral circuit of the chip and other circuits in the driving device where the chip is located, the chip can further comprise a pin for outputting a leakage protection control signal and a pin for connecting to the power supply circuit. The leakage protection control signal is generated and output by the leakage protection circuit when leakage is determined after interval sampling and voltage division detection. Other circuits on the power supply circuit can give corresponding leakage protection response based on the received leakage protection control signal. Among them, the other circuits include but are not limited to: filter circuit and driving circuit, etc. For example, referring to Figure 16Fig. 1 shows a structure diagram of the leakage protection circuit and the driving circuit, the leakage protection circuit 41 is connected to the power supply line and the ground through the chip pin, the driving circuit 42 contains an enable control unit (not shown), the control end (i.e. the enable end EN) of the enable control unit is connected to the output end of the leakage protection circuit 41 through another chip pin and connected to the switching device or the logic circuit (not shown) in the driving circuit 42, when the enable control unit receives the leakage protection control signal, it controls the corresponding switching device or the logic circuit to make the driving circuit stop supplying power to the load until the leakage protection control signal is disabled, at this time the driving circuit 42 can perform the driving operation. For example, please refer to Figure 17 Fig. 2 shows another structure diagram of the leakage protection circuit and the driving circuit, the leakage protection circuit 51 is connected to the power supply line and the ground through the chip pin, the driving circuit 52 contains another enable control unit and the existing driving controller, the control end of the enable control unit is connected to the output end of the leakage protection circuit through another chip pin, the input end is connected to the power supply end of the driving controller, and the output end is connected to the ground, when the leakage protection circuit 51 outputs the leakage protection control signal, the enable control unit gives the corresponding leakage protection response based on the leakage protection control signal, so that the existing driving controller cannot reach its normal working voltage.

[0134] Here, the sampling interval of the leakage protection circuit can be set based on the voltage variation period in the power supply line. For example, the voltage peak or valley in each or interval at least one voltage variation period after rectification is sampled, or the fixed voltage region between the voltage peak and valley in each or interval at least one voltage variation period after rectification is sampled. In order to ensure that the human body will not be injured by continuous electric shock when being accidentally touched, the sampling interval is in the order of milliseconds or even microseconds. For example, the sampling interval can be interval half a voltage variation period, interval one voltage variation period, or interval multiple voltage variation periods. The sampling interval can be realized by the circuit structure designed by the voltage variation period in the leakage protection circuit. Alternatively, the sampling interval is set according to the pre-set time length. For example, the leakage protection circuit contains a capacitor and a resistor, and the sampling interval is determined by the charging time of the capacitor, wherein the technician can design the corresponding sampling interval by configuring the resistor. The resistor can be an adjustable resistor or a fixed resistor.

[0135] In this case, the voltage detection mode of the leakage protection circuit can determine whether the voltage of the AC input power supply is divided by comparing the sampled voltage with the preset reference voltage corresponding to the sampling time, so as to determine whether the power supply line where the load is located is turned on. For example, the leakage protection circuit starts timing of the sampling interval by detecting the voltage zero point on the power supply line, samples the electrical signal on the power supply line when the timing reaches, and determines the voltage threshold at the timing reaching time according to the voltage variation period of the power supply line, compares the sampled electrical signal voltage with the voltage threshold, and determines whether the voltage of the AC input power supply is divided. When it is determined that the voltage is divided, the leakage protection circuit can output a leakage protection control signal to control other circuits on the power supply line to give a corresponding leakage protection response, or disconnect the connected power supply line.

[0136] In some embodiments, the leakage protection circuit samples the electrical signal voltage according to the interval set according to the voltage variation period, and can determine whether the voltage of the AC input power supply is divided by comparing the electrical signal voltage with the preset power-off protection voltage threshold. To this end, as shown in Figure 2 The leakage protection circuit includes a detection unit 11, a sampling unit 12, and a control unit 13.

[0137] The detection unit 11 is connected to the power supply line through an HV pin, and is used to output a sampling control signal based on the detection of the voltage of the power supply line. In this case, the detection unit 11 can detect the voltage variation on the power supply line in real time, and determine that the sampling interval is reached and output the sampling control signal when the voltage variation is detected to reach the preset reference voltage value. The preset reference voltage value can correspond to any voltage value in the voltage variation period, such as the peak value, the valley value, the intermediate value, etc. The sampling control signal is used to control the sampling unit to perform the sampling operation.

[0138] In some embodiments, the detection unit includes a voltage limiting detection circuit module connected to the power supply line, which is used to detect the voltage of the power supply line and output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval. The voltage limiting interval is intercepted within the voltage variation range of the power supply line. For example, the voltage limiting interval is [V1, V2], where 0≤V1

[0139] To achieve the above-mentioned voltage limiting detection, the voltage limiting detection circuit module includes at least one comparator for comparing whether the voltage on the power supply line reaches within the preset voltage limiting interval. The comparator is used to provide the boundary threshold of the voltage limiting interval. The comparator includes but is not limited to a hysteresis comparator, a window comparator, a zero-crossing comparator, etc. In some embodiments, the voltage limiting detection circuit module is a valley bottom detection circuit designed based on the sinusoidal variation. For example, as shown inFigure 3 As shown, the voltage limit detection circuit module comprises a zero-crossing comparator, and the negative input terminal of the zero-crossing comparator is connected to the boundary threshold of the voltage limit interval, and the positive input terminal is connected to the power supply circuit directly or through a circuit comprising a sampling resistor. When the voltage variation of the power supply circuit is less than the boundary threshold, a first sampling control signal is output. The boundary threshold is greater than zero, so that the first sampling control signal maintains an effective duration, while the voltage instability of the power supply circuit can cause false triggering or false non-triggering. The sampling unit can sample the electric signal according to the rising edge or falling edge of the first sampling control signal, or continuously sample the electric signal during the effective period of the first sampling control signal. The sampling unit controlled by the first sampling control signal performs a sampling action once in each voltage variation cycle.

[0140] In some embodiments, the detection unit further comprises a timing circuit module. The timing circuit module is connected to the voltage limit detection circuit module, and is configured to output a second sampling control signal based on the first sampling control signal. The timing circuit module outputs the second sampling control signal based on the rising edge of the first sampling control signal, and starts the sampling unit to sample based on the second sampling control signal. The duration of the second sampling control signal can be regarded as the duration of the sampling unit allowed to sample. Defining the sampling duration can effectively prevent false on operation caused by the jitter of the sampled electric signal. For example, as shown in FIG. 4, the timing circuit module outputs the second sampling control signal based on the rising edge of the first sampling control signal, and the sampling unit samples the electric signal during the duration of the second sampling control signal. Figure 4 As shown, the timing circuit module outputs the second sampling control signal based on the rising edge of the first sampling control signal, and counts the duration of the second sampling control signal. During the counting duration, the sampling unit samples the electric signal. In order to prevent false on operation caused by the jitter of the sampled electric signal, the timing circuit module outputs the second sampling control signal during the duration of the first sampling control signal, i.e., the duration of the second sampling control signal is less than the duration of the first sampling control signal. The sampling unit samples the electric signal based on the second sampling control signal.

[0141] In some specific examples, the timing circuit module comprises a clock signal generator, a counter Counter 1, a logic device group, a switch and the like. The switch is connected with the voltage limiting detection circuit module, and the switch is connected with the control end of the counter Counter 1. The input end of the counter Counter 1 is connected with the clock signal generator, and the output end of the counter Counter 1 is connected with the logic device group. The switch is turned on and off based on the first sampling control signal. When the switch is turned on, the counter Counter 1 starts to count the received clock signal. Before the number of counted clock signal pulses of the counter Counter 1 reaches a preset number, the logic device group outputs the second sampling control signal. When the number of counted clock signal pulses of the counter Counter 1 reaches the preset number, the control logic device group does not output the second sampling control signal until the next first sampling control signal arrives.

[0142] In yet some specific examples, as Figure 5The timing circuit module includes a capacitor, a capacitor charging controller, a capacitor discharging controller, two comparators and a logic device group, etc. The capacitor discharging controller is connected between the two ends of the capacitor; the control end of the capacitor charging controller receives a first sampling control signal, the input end is connected to a constant voltage, and the output end is connected to the capacitor; the capacitor is directly or through a resistor connected to the ground; the input end of the capacitor is also connected to comparators A1 and A2; the other input end of the comparator A1 is connected to a reference voltage Vref 1, and the other input end of the comparator A2 is connected to a reference voltage Vref 2; the output ends of the comparators A1 and A2 are connected to the logic device group, and the logic device group outputs the second sampling control signal. The capacitor charging controller and the capacitor discharging controller can be controlled switches, such as MOS tubes. The reference voltage Vref 1 is close to 0V, and Vref 2 is a voltage value higher than Vref 1. Through the design of the technical personnel, the time length of the capacitor voltage from Vref 1 to Vref 2 is less than the time length of the first sampling control signal. Initially, the capacitor discharging controller shorts the capacitor and the capacitor charging controller is disconnected, so that the capacitor is in a zero charge state, and correspondingly, the comparator A1 outputs a low level; when the capacitor charging controller receives the first sampling control signal, the capacitor charging controller is turned on and the capacitor discharging controller is disconnected, so that the capacitor is charged, when the capacitor voltage is higher than the reference voltage Vref, the comparator A1 outputs a high level and the comparator A2 still outputs a low level, and the logic device group outputs the second sampling control signal according to the preset logic configuration when the comparator A1 outputs a high level and the comparator A2 outputs a low level; when the capacitor voltage reaches Vref 2, the comparator A2 jumps to a high level, and the logic device group does not output the second sampling control signal according to the logic configuration when the comparators A1 and A2 both output a high level, and controls the capacitor charging controller to be disconnected to make the capacitor no longer charge, and controls the capacitor discharging controller to be turned on to discharge the capacitor charge, until the next first sampling control signal arrives.

[0143] In some embodiments, the timing circuit module also sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing expires. Please refer to Figure 6 which shows a waveform diagram of the relationship between the second sampling control signal and the first sampling control signal output by the timing circuit module. As shown in the figure, the detection timing can make the timing circuit module not output the second sampling control signal based on the first sampling control signal within the time interval T2 of at least one first sampling control signal.

[0144] In some embodiments, the timing circuit module comprises a plurality of counters, one of which, Counter 1, is used to count the duration of the second sampling control signal, and another, Counter 2, is used to count the detection timing. The timing circuit module further comprises a clock signal generator, a switch and a logic device group. The switch is turned on and off based on the first sampling control signal, and when turned on, it enables the counter Counter 1 to start counting the received clock signal. Before the number of pulses of the clock signal counted by the counter Counter 1 reaches a preset value, the logic device group outputs the second sampling control signal. When the number of pulses counted by the counter Counter 1 reaches the count value, the control logic device group stops outputting the second sampling control signal, and at this time, the counter Counter 2 starts counting the number of pulses of the received clock signal. When the counter Counter 2 reaches its count value, i.e., the detection timing is over, it controls the logic device group to output the second sampling control signal.

[0145] In yet some embodiments, as Figure 7As shown, the timing circuit module can include a plurality of capacitors, each capacitor being configured with a capacitor charging controller and a capacitor discharging controller, a plurality of comparators, and a logic device group, etc. Among them, the configured capacitor discharging controller is connected between the two ends of the corresponding capacitor; the control end of the configured capacitor charging controller receives a first sampling control signal, the input end is connected to a constant voltage, and the output end is connected to the corresponding capacitor; each capacitor is directly or through a resistor connected to ground; the input end of one of the capacitors C1 is also connected to comparators A1 and A2; wherein the other input end of comparator A1 is connected to reference voltage Vref 1, and the other input end of comparator A2 is connected to reference voltage Vref 2; comparator A3 is connected to another capacitor C2 and is connected to reference voltage Vref 3; the output ends of comparators A1, A2 and A3 are all connected to a logic device group, and the logic device group outputs the second sampling control signal. Wherein the reference voltage Vref 1 is close to 0V, and Vref 2 is a voltage value higher than Vref 1. Through the design of the technical personnel, the time length of the capacitor C1 voltage from Vref 1 to Vref 2 is less than the time length of the first sampling control signal; and the time length of the capacitor C2 voltage from the initial value (such as 0v) to Vref 3 is greater than the time length of a first sampling control signal. Initially, the capacitor discharging controller CDC1 shorts the capacitor C1 and the capacitor charging controller CCC1 is disconnected, so that the capacitor C1 is in a zero charge state, at the same time, the capacitor discharging controller CDC2 connected with the capacitor C2 is disconnected and the capacitor charging controller CCC2 is turned on, so that the capacitor C2 is in a charge storage state; correspondingly, the comparators A1 and A2 output low level, and the comparator A3 outputs high level; when the capacitor charging controller CCC1 connected with the capacitor C1 receives the first sampling control signal, the capacitor charging controller CCC1 connected with the capacitor C1 is turned on and the capacitor discharging controller CDC1 is disconnected, so that the capacitor is charged, when the capacitor voltage is higher than the reference voltage Vref, the comparator A1 outputs high level and the comparator A2 still outputs low level, and the logic device group outputs the second sampling control signal according to the preset logic configuration when the comparators A1 and A3 output high level and the comparator A2 outputs low level. At this time, the capacitor discharging controller CDC2 and the capacitor charging controller CCC2 are controlled by the second sampling control signal to discharge the capacitor C2, and the comparator A3 outputs low level; however, the capacitor C1 continues to charge so that the voltage reaches Vref 2, the comparator A2 jumps to high level, and the logic device group no longer outputs the second sampling control signal according to the logic configuration when the comparators A1 and A2 both output high level and the comparator A3 outputs low level, and controls the capacitor charging controller CCC1 to be disconnected to stop charging the capacitor C1, and controls the capacitor discharging controller CDC1 to be turned on to discharge the capacitor C1.When the capacitor C1 discharges, the capacitor C2 capacitor charging controller CCC2 is turned on and the capacitor discharge controller CDC2 is turned off, so that the capacitor C2 is charged until the capacitor C2 voltage reaches Vref 3, the comparator A3 outputs high level, and the logic device group outputs the second sampling control signal according to the level change of the comparators A1 and A2 according to the logic configuration when the comparator A3 outputs high level.

[0146] It should be noted that the circuit structure provided by the timing circuit module described above is only an example and is not a limitation of the circuit structure of the timing circuit module in the present application. In fact, according to the design of the timing logic by the skilled person, other timing circuit modules containing comparators, logic device groups, capacitors, or timing circuit modules containing clock signal generators and counters can also be proposed. Herein, detailed description is not made, however, the timing circuit modules designed based on the technical inspiration of the above-mentioned timing circuit modules should be considered as specific examples of the present application. In addition, the devices in the above-mentioned timing circuit module can be fixedly arranged in the chip. In order to facilitate various types of alternating current cycles provided by different alternating current power supplies, the devices used for timing in the above-mentioned timing circuit module, such as capacitors and their peripheral devices, or counters, etc. can be arranged outside the chip, and these devices are controlled and data is obtained through corresponding pins. In this way, it is convenient for the skilled person to select according to the specific design needs. Based on the design of the above-mentioned timing circuit modules, an example is that the sampling unit in the leakage protection circuit samples the voltage of the power supply line during receiving the second sampling control signal.

[0147] It should also be noted that the logic device group mentioned in any of the above examples can contain at least one logic device according to the actual logic design needs, and the corresponding logic configuration is realized by electrically connecting each logic device. Among them, the logic device includes but is not limited to AND gate, OR gate, NAND gate, NOT gate, encoder, decoder, selector, etc.

[0148] The sampling unit is connected with the detection unit, and is used for obtaining the sampling electric signal of the power supply line based on the received sampling control signal.

[0149] Please refer to Figure 8, which shows the structure of the leakage protection circuit in an embodiment. As shown in the figure, the sampling unit 12 comprises a controlled switch and a sampling resistor, wherein the control end of the controlled switch is connected to the output end of the detection unit, one access end of the controlled switch is connected to the power supply circuit through the HV pin, and the other access end is connected to the ground through the sampling resistor (i.e. connected to the GND pin), and the sampling resistor is also connected to the control unit 13. The controlled switch comprises, but is not limited to, any one of the following: a bipolar transistor (BJT), a junction field effect transistor (JFET), a depletion MOS power tube, a silicon-controlled dimmer, etc. When the detection unit 11 outputs a sampling control signal, the controlled switch is turned on, and the control unit 13 obtains the voltage of the sampled electric signal from the sampling resistor.

[0150] In a specific example, as shown in Figure 8 , the controlled switch is exemplified by a MOS power tube, the gate of the MOS power tube is connected to the output end of the timing circuit module, the drain of the MOS power tube is connected to the power supply circuit, and the source of the MOS power tube is connected to the sampling resistor. According to the foregoing timing circuit module, the MOS power tube is turned on during the reception of the first sampling control signal or the second sampling control signal so that the control unit obtains the sampled voltage.

[0151] The control unit is used to compare the voltage of the sampled electric signal with a preset power-off protection voltage threshold and provide leakage protection based on the comparison result.

[0152] Here, the power-off protection voltage threshold preset by the control unit can be provided by a constant voltage circuit. The power-off protection voltage threshold can be designed based on the voltage drop of the sampling unit affected by the human body voltage division alternating current. When the control unit determines that the sampled voltage is lower than the power-off protection voltage threshold, the power supply circuit can be disconnected or a leakage protection control signal can be output; otherwise, the power supply loop of the power supply circuit is turned on so that the load works normally.

[0153] In an embodiment, the control unit comprises a comparison circuit module, a logic latch circuit module, and a switch circuit module. The comparison circuit module is used to compare the voltage of the sampled electric signal with a preset power-off protection voltage threshold and output a comparison result. The logic latch circuit module is connected to the comparison circuit module and is used to latch the comparison result. The switch circuit module is connected to the logic latch circuit module and is used to control the power supply circuit to be turned on or disconnected based on the latched signal.

[0154] Please refer to Figure 9 , which shows the corresponding Figure 8The waveforms of the sampled voltage received by the comparison circuit module are shown in the leakage protection circuit. As shown in the figure, when the load is connected to the power supply line and there is no human error, the sampled voltage is higher than the power-off protection voltage threshold Vref; when the load is connected to the power supply line and there is human error, the sampled voltage is lower than the power-off protection voltage threshold Vref due to the voltage drop of the human body. When the sampled voltage is higher than the power-off protection voltage threshold Vref, the comparison circuit module outputs a jump signal, the logic latch circuit module latches the jump signal and outputs a latch signal to the switch circuit module, and the switch circuit module controls the power supply line to be turned on. Otherwise, the comparison circuit module does not output a jump signal, the logic latch circuit module does not output a latch signal, and the switch circuit module maintains the power supply line to be turned off. Thus, the load and personal safety are protected.

[0155] In a specific example, the comparison circuit module includes a comparator, and the switch circuit module includes a controlled switch and a switch drive module. The negative input terminal of the comparator is connected to the power-off protection voltage threshold, the positive input terminal is connected to the input terminal of the logic latch circuit module, and the output terminal of the logic latch circuit module is the output terminal of the detection unit. The switch circuit module includes a gate drive module and a MOS power tube, for example. The gate of the MOS power tube is connected to the output terminal of the comparator through the gate drive module, and the source and drain are connected to the power supply line. When the load is normally connected to the power supply line, the comparator always outputs a high level, and the MOS power tube turns on the power supply line to make the load work normally. Please refer to Figure 8 The logic latch circuit module latches the high level state when the output of the comparison circuit module jumps from low level to high level, and latches the low level state when the output of the comparison circuit module jumps from high level to low level. Initially, the logic latch circuit module is in low level state, and the switch circuit module disconnects the power supply line based on the received low level state latch signal. When the output of the comparison circuit module jumps from low level to high level, the logic latch circuit module latches the high level state and outputs a high level state latch signal, and the switch circuit module connects the power supply line. Therefore, the latch signal is used to represent the leakage protection control signal of the leakage protection circuit.

[0156] Here, the MOS power tube in the controlled switch can also be replaced by any one of a triode (BJT), a junction field effect transistor (JFET), a depletion MOS power tube, a silicon light dimmer, etc. The switch drive module is not necessarily a gate drive module, but can be adjusted according to actual design needs. For example, the switch circuit module includes a MOS power tube and a source drive module, etc.

[0157] In yet some embodiments, the output of the logic latching circuit module is connected to other circuits (such as the aforementioned driving circuit, etc.) on the power supply line, so that the other circuits provide corresponding leakage protection based on the latching signal. Details are not repeated here.

[0158] It should be noted that the comparison relationship between the sampling electrical signal voltage with human body voltage and the leakage protection voltage threshold value, and the comparison relationship between the sampling electrical signal voltage without human body voltage and the leakage protection voltage threshold value shown in the above Figure 9 are related to the circuit structure of the sampling unit. When the circuit structure of the sampling unit is configured such that the sampled electrical signal voltage with human body voltage is higher than the sampled electrical signal voltage without human body voltage, the corresponding control unit should provide corresponding leakage protection based on the opposite comparison result shown in the above Figure 9 . Wherein, the connection mode of the circuit structure of the sampling unit can also be that one access end of the controlled switch is connected to the power supply line through a sampling resistor, and the other access end is grounded. Details are not listed here.

[0159] In order to prevent the logic latching circuit module from providing false latching signals in the restart operation of the user after turning off the load, the logic latching circuit module needs to be reset to the initial low state when the load is powered off. In some specific examples, the logic latching circuit module is reset based on the fact that the leakage protection circuit is in an underpower state.

[0160] Wherein, the underpower state is a state in which the power supply of the load cannot reach its working voltage due to external factors or electrical components on the power supply line during normal operation of the load, thereby causing the load to stop working. The underpower state of the leakage protection circuit can be caused by human power-off or by abnormality of internal (or external) electrical components of the leakage protection circuit. For example, the situations that cause the leakage protection circuit to be in an underpower state include but are not limited to: the off state of the leakage protection circuit during power-off; and the state of the leakage protection circuit during which the power supply system cannot provide corresponding working voltage to the active devices in the leakage protection circuit.

[0161] The logic circuit module can reset its latched signal by detecting the under-voltage state of the leakage protection circuit. In a specific example, the reset terminal of the logic latch circuit module is connected to the power supply line. When the power supply line is powered off, the leakage protection circuit is in an under-voltage state, and the corresponding reset terminal receives a valid reset signal. In another specific example, the reset terminal of the logic latch circuit module is connected to an under-voltage protection circuit for protecting the leakage protection circuit. When the under-voltage protection circuit generates an under-voltage protection signal due to detecting the under-voltage state of the leakage protection circuit, the reset terminal of the logic latch circuit module takes the under-voltage protection signal as the valid reset signal. Thus, the reset operation of the logic latch circuit module is realized.

[0162] In addition, due to the arrangement of the logic latch circuit module, when the power supply line is connected, the detection unit and the sampling unit do not necessarily need to continue to provide the voltage of the electrical signal to continuously control the switch circuit unit to be turned on. Therefore, the interval sampling of the power supply line is stopped when the power supply line is controlled to be turned on. The leakage protection circuit can add a control circuit module in the detection unit or the sampling unit to correspondingly stop detection or sampling. In some specific examples, the control unit is also connected to the detection unit to control the detection unit to stop outputting the sampling control signal when the power supply line is controlled to be turned on. For example, the timing circuit module in the detection unit is also connected to the output terminal of the logic latch circuit module in the control unit, and when the logic latch circuit module outputs a high-level state latched signal, the timing circuit module does not output the first sampling control signal or the second sampling control signal. Thus, the problem of false power-off of the load caused by unstable voltage of the alternating input power supply can be effectively prevented.

[0163] Now, the leakage protection circuit structure shown in Figure 10 and Figure 11The working process of the chip is described by taking the chip packaging structure in the chip as an example. When a load is connected to a power supply line, the HV pin is electrically connected to the power supply line, the voltage on the power supply line can be obtained by the voltage limiting detection circuit module 111 connected to the HV pin in the chip in real time, and when the obtained voltage falls within a preset valley voltage interval, a first sampling control signal is output. The timing circuit module 112 outputs a second sampling control signal based on the first sampling control signal and starts timing the detection timing, wherein the duration of the second sampling control signal is shorter than that of the first sampling control signal. The sampling unit 12 samples the voltage of the power supply line based on the second sampling control signal and provides it to the comparison circuit module 131 in the control unit 13 to compare the sampled voltage with the preset power-off protection voltage threshold. If the sampled voltage is lower than the power-off protection voltage threshold, it means that the AC input power source is artificially divided, the comparison circuit module 131 outputs a low-level signal, and the logic latch circuit module 132 controls the switch circuit module to disconnect the power supply line based on the low-level signal. If the sampled voltage is higher than the power-off protection voltage threshold, it means that there is no artificial electric shock, the comparison circuit module 131 outputs a high-level signal, and the logic latch circuit module 132 outputs a high-level state latch signal based on the high-level signal and controls the switch circuit module 133 to connect the DRAIN and GND pins, so that the power supply line forms a loop.

[0164] During the period when the power supply line is not connected, the timing circuit module 112 does not output the second sampling control signal based on the first sampling control signal when the detection timing does not arrive, and only responds to the first sampling control signal when the detection timing times out. In addition, during the period when the power supply line is connected, the timing circuit module 112 is controlled not to output the second sampling control signal to disconnect the loop where the sampling resistor is located, thereby reducing the electrical loss of the leakage protection circuit.

[0165] The application also provides a driving device. The driving device is used to provide a DC power supply higher than the human body safety voltage for a load. Taking an LED load as an example, the driving device is used as an LED driving device to drive the LED load to work normally. Here, the LED load takes an LED daylight lamp as an example. When the LED daylight lamp is installed, people may touch its needle-shaped pin due to misoperation, and when the needle-shaped pin is connected to the LED driving device at the same time, the human body will be electrically shocked. Therefore, a leakage protection circuit is configured in the LED driving device. The driving device provided by the application can be installed in an AC input source and provide a power supply line for the LED load as an LED driving device.

[0166] Figure 12A schematic diagram of the frame structure of a drive device is shown. As shown, the drive device includes a rectifier circuit 21, a leakage protection circuit 22, and a drive circuit 23. The drive device is used to provide a DC power supply higher than the safe voltage for human use to a load 24. Taking an LED load as an example, the drive device is an LED driver and provides leakage protection for both the operator and the LED load when the LED load is connected to the power supply line. The drive device provides leakage protection when it detects voltage drop caused by human error, and it connects the power supply line and supplies power to the LED load when no human error is detected.

[0167] The rectifier circuit 21 is used to rectify the connected AC power and supply it to the load's power supply line. Here, the rectifier circuit 21 is connected to an AC input source and rectified by a rectifier bridge consisting of four diodes.

[0168] The leakage protection circuit 22 is connected to the rectifier circuit 21 and is used to perform interval sampling of the power supply line, detect the voltage of the sampled electrical signal to determine whether the voltage of the AC input power supply is divided, and provide leakage protection based on the determined result.

[0169] like Figure 12 As shown, the leakage protection circuit 22 is connected between the output terminal of the rectifier bridge and the ground terminal. The leakage protection circuit can be integrated into a chip. In some embodiments, such as... Figure 11 As shown, the HV pin of the chip is connected to the output terminal of the rectifier bridge, the GND pin is connected to the ground terminal of the rectifier bridge, and the DRAIN pin of the chip is connected to the circuit of the power supply line of the load. Therefore, the conduction or disconnection of the grounded portion of the power supply line of the load is controlled by the leakage current protection circuit. That is, when the leakage current protection circuit detects that the voltage of the AC input power supply is divided, the power supply line is disconnected; otherwise, the power supply line is connected. The number of pins of the chip is related to the integrated circuit module. For example, the chip includes a leakage current protection circuit, and the constant voltage power supply used by the leakage current protection circuit can be shared with the constant voltage power supply in other circuits in the drive device or configured separately and integrated into the chip. In the case of a shared constant voltage power supply, the chip also includes pins for connecting to the constant voltage power supply.

[0170] In some other embodiments, according to the actual design requirements of the peripheral circuit of the chip and other circuits in the driving device where the chip is located, the chip can include a pin for outputting a leakage protection control signal and a pin for accessing a power supply circuit. The leakage protection control signal is generated and outputted by the leakage protection circuit when leakage is detected after being sampled and divided. Other circuits on the pin power supply circuit can give corresponding leakage protection response based on the received leakage protection control signal. The other circuits include but are not limited to filter circuits and driving circuits, etc. For example, please refer to Figure 16 which shows a structural diagram of the leakage protection circuit and the driving circuit. The leakage protection circuit 41 is connected to the power supply circuit and the ground through the chip pin. The driving circuit 42 includes an enable control unit (not shown) whose control end (i.e. enable end EN) is connected to the output end of the leakage protection circuit 41 through another chip pin and controls the switching device or logic circuit (not shown) in the driving circuit 42. When the enable control unit receives the leakage protection control signal, it controls the switching device or logic circuit in the driving circuit 42, so that the energy converted by the driving circuit 42 cannot be provided to the load until the leakage protection control signal is disabled and the driving circuit 42 can perform driving operation. For another example, please refer to Figure 17 which shows another structural diagram of the leakage protection circuit and the driving circuit. The leakage protection circuit 51 is connected to the power supply circuit and the ground through the chip pin. The driving circuit 52 includes another enable control unit and the circuit in the existing driving controller. The control end of the enable control unit is connected to the output end of the leakage protection circuit through another chip pin, the input end is connected to the power supply end of the driving chip, and the output end is connected to the ground. When the leakage protection circuit 51 outputs the leakage protection control signal, the enable control unit gives corresponding leakage protection response based on the leakage protection control signal, i.e. connects the power supply end VCC in the existing driving controller to the ground, so that the active device in the circuit in the existing driving controller cannot reach its working voltage.

[0171] In this embodiment, the sampling interval of the leakage protection circuit is set based on the voltage variation period of the power supply line. The sampling interval can be realized by the circuit structure in the detection unit of the leakage protection circuit for controlling the sampling interval. For example, the sampling interval can be set to sample the voltage peak or valley of each or every interval of at least one voltage variation period after rectification, or to sample the fixed voltage region between the voltage peak and valley of each or every interval of at least one voltage variation period after rectification. In order to ensure that the human body will not be continuously shocked when being accidentally touched, the sampling interval is in the order of milliseconds or even microseconds. For example, the sampling interval can be set to sample every half of the voltage variation period, every one voltage variation period, or every multiple voltage variation periods. The sampling interval can be realized by the circuit structure designed based on the voltage variation period in the leakage protection circuit. Alternatively, the sampling interval can be set according to the preset time length. For example, the leakage protection circuit includes a capacitor and a resistor, and the sampling interval is determined by the charging time of the capacitor. The skilled person can configure the resistor to design the corresponding sampling interval. The resistor can be an adjustable resistor or a fixed resistor.

[0172] In this embodiment, the voltage detection method of the leakage protection circuit can determine whether the voltage of the alternating input power supply is divided by comparing the sampled voltage with the reference voltage corresponding to the sampling time. For example, the leakage protection circuit starts the timing of the sampling interval by detecting the voltage zero point on the power supply line, samples the electrical signal on the power supply line when the timing reaches, and compares the sampled voltage with the voltage threshold value at the timing reaching time according to the voltage variation period of the power supply line to determine whether the voltage of the alternating input power supply is divided. When it is determined that the voltage is divided, the leakage protection circuit can output a leakage protection control signal to control other circuits on the power supply line to give a corresponding leakage protection response, or disconnect the connected power supply line.

[0173] In some embodiments, the leakage protection circuit samples the voltage of the electrical signal according to the interval set based on the voltage variation period, and determines whether the voltage of the alternating input power supply is divided by comparing the voltage of the electrical signal with the preset power-off protection voltage threshold. For this purpose, as shown in FIG. 1, the leakage protection circuit includes a detection unit 11, a sampling unit 12, and a control unit 13. Figure 2

[0174] ​The detection unit 11 is connected to the power supply line and is configured to output a sampling control signal based on the detection of the voltage of the power supply line. Herein, the detection unit 11 can detect the voltage change on the power supply line in real time, and determine that the sampling interval is reached and output a sampling control signal when the detected voltage changes to a preset reference voltage value. Among them, the preset reference voltage value can correspond to any voltage value in the voltage change period, such as peak value, valley value, intermediate value, etc. The sampling control signal is used to control the sampling unit to perform a sampling operation.

[0175] In some embodiments, the detection unit includes a voltage-limiting detection circuit module connected to the power supply line for detecting the voltage of the power supply line, and outputting a first sampling control signal when the detected voltage falls within a preset voltage-limiting interval. Among them, the voltage-limiting interval is intercepted within the voltage change range of the power supply line. For example, the voltage-limiting interval is [V1, V2], where 0 ≤ V1 < V2 < Vmax, and Vmax is the maximum value of the voltage change range.

[0176] To implement the above voltage-limiting detection, the voltage-limiting detection circuit module includes at least one comparator, and the comparator is used to compare whether the voltage on the power supply line reaches within the preset voltage-limiting interval. Among them, the comparator is used to provide the boundary threshold of the voltage-limiting interval. The comparator includes but is not limited to a hysteresis comparator, a window comparator, a zero-crossing comparator, etc. In some embodiments, the voltage-limiting detection circuit module is a bottom detection circuit designed based on a sine wave change. For example, as Figure 3 shown, the voltage-limiting detection circuit module includes a zero-crossing comparator, and the negative input terminal of the zero-crossing comparator is connected to the boundary threshold of the voltage-limiting interval, and the positive input terminal is directly or through a circuit including a sampling resistor connected to the power supply line. When the voltage change of the power supply line is less than the boundary threshold, a first sampling control signal is output. Among them, the boundary threshold is greater than zero, so that the first sampling control signal maintains an effective duration, and at the same time can tolerate the false triggering or false non-triggering caused by the unstable voltage of the power supply line. The sampling unit can sample the electrical signal according to the rising edge or falling edge of the first sampling control signal, or continuously sample the electrical signal during the effective period of the first sampling control signal. The sampling unit controlled by the first sampling control signal will perform a sampling action in each voltage change cycle.

[0177] In some embodiments, the detection unit further comprises a timing circuit module. The timing circuit module is connected to the voltage-limiting detection circuit module, and is configured to output a second sampling control signal based on the first sampling control signal. The timing circuit module outputs the second sampling control signal based on a rising edge of the first sampling control signal, and the sampling unit is enabled to sample based on the second sampling control signal. The duration of the second sampling control signal can be regarded as the duration of the sampling unit to allow sampling. Limiting the sampling duration can effectively prevent the false-on operation caused by the jitter of the sampled electrical signal. For example, as shown in Figure 4 FIG. 7 is a timing diagram of the voltage-limiting detection circuit module and the timing circuit module using the waveforms of the first sampling control signal and the second sampling control signal. The timing circuit module outputs the second sampling control signal based on the rising edge of the first sampling control signal, and counts the duration of the second sampling control signal. During the counted duration, the sampling unit samples the electrical signal. In order to prevent the false-on operation caused by the jitter of the sampled electrical signal, the timing circuit module outputs the second sampling control signal during the duration of the first sampling control signal, i.e., the duration of the second sampling control signal is less than that of the first sampling control signal. The sampling unit samples the electrical signal based on the second sampling control signal.

[0178] In some specific examples, the timing circuit module includes a clock signal generator, a counter Counter 1, a logic device group, and a switch, etc. The switch is connected to the voltage-limiting detection circuit module, and is connected to the control terminal of the counter Counter 1. The input terminal of the counter Counter 1 is connected to the clock signal generator, and the output terminal of the counter Counter 1 is connected to the logic device group. The switch is turned on and off based on the first sampling control signal. When the switch is turned on, the counter Counter 1 starts to count the received clock signal. Before the number of pulses of the counted clock signal reaches a preset value, the logic device group outputs the second sampling control signal. When the number of pulses counted by the counter Counter 1 reaches the counting value, the logic device group is controlled not to output the second sampling control signal until the next first sampling control signal arrives.

[0179] In some specific examples, please refer to Figure 5The timing circuit module comprises a capacitor, a capacitor charging controller, a capacitor discharging controller, two comparators and a logic device group. The capacitor discharging controller is connected between the two ends of the capacitor. The control end of the capacitor charging controller receives a first sampling control signal, the input end is connected to a constant voltage, and the output end is connected to the capacitor. The capacitor is directly or through a resistor connected to the ground. The input end of the capacitor is also connected to comparators A1 and A2. The other input end of the comparator A1 is connected to a reference voltage Vref 1, and the other input end of the comparator A2 is connected to a reference voltage Vref 2. The output ends of the comparators A1 and A2 are connected to the logic device group, and the logic device group outputs the second sampling control signal. The capacitor charging controller and the capacitor discharging controller can be controlled switches, such as MOS tubes. The reference voltage Vref 1 is close to 0V, and Vref 2 is a voltage value higher than Vref 1. Through the design of the technical personnel, the time length of the capacitor voltage from Vref 1 to Vref 2 is less than the time length of the first sampling control signal. Initially, the capacitor discharging controller shorts the capacitor and the capacitor charging controller is disconnected, so that the capacitor is in a zero charge state, and the comparator A1 outputs a low level. When the capacitor charging controller receives the first sampling control signal, the capacitor charging controller is turned on and the capacitor discharging controller is disconnected, so that the capacitor is charged. When the capacitor voltage is higher than the reference voltage Vref, the comparator A1 outputs a high level and the comparator A2 still outputs a low level. The logic device group outputs the second sampling control signal according to the preset logic configuration when the comparator A1 outputs a high level and the comparator A2 outputs a low level. When the capacitor voltage reaches Vref 2, the comparator A2 jumps to a high level, and the logic device group does not output the second sampling control signal according to the logic configuration when the comparators A1 and A2 both output a high level, and controls the capacitor charging controller to be disconnected to stop charging the capacitor, and controls the capacitor discharging controller to be turned on to discharge the capacitor charge, until the next first sampling control signal arrives.

[0180] In still other embodiments, the timing circuit module also sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing expires. Please refer to FIG. 5, which is a waveform diagram of the relationship between the second sampling control signal and the first sampling control signal output by the timing circuit module. As shown in the figure, the detection timing can make the timing circuit module not output the second sampling control signal based on the first sampling control signal within the time interval T2 of at least one first sampling control signal.

[0181] In some specific examples, the timing circuit module comprises a plurality of counters, one of which, Counter 1, is used to count the duration of the second sampling control signal, and another, Counter 2, is used to count the detection timing. The timing circuit module further comprises a clock signal generator, a switch and a logic device group. The switch is turned on and off based on the first sampling control signal, and when turned on, it enables the counter Counter 1 to start counting the received clock signal. Before the number of pulses of the clock signal counted by the counter Counter 1 reaches a preset value, the logic device group outputs the second sampling control signal. When the number of pulses counted by the counter Counter 1 reaches the count value, the control logic device group stops outputting the second sampling control signal, at which time the counter Counter 2 starts counting the number of pulses of the received clock signal. When the counter Counter 2 reaches its count value, i.e. the detection timing is over, it controls the logic device group to output the second sampling control signal.

[0182] In yet some specific examples, please refer to Figure 7It is a structural schematic diagram of the timing circuit module in another embodiment. As shown in the figure, the timing circuit module can include a plurality of capacitors, each of which is configured with a capacitor charging controller and a capacitor discharging controller, a plurality of comparators, and a logic device group, etc. Among them, the configured capacitor discharging controller is connected between the two ends of the corresponding capacitor; the control end of the configured capacitor charging controller receives a first sampling control signal, the input end accesses a constant voltage, and the output end is connected to the corresponding capacitor; each of the capacitors is directly or through a resistor connected to ground; the input end of one of the capacitors C1 is also connected to comparators A1 and A2; among them, the other input end of comparator A1 accesses reference voltage Vref 1, and the other input end of comparator A2 accesses reference voltage Vref 2; comparator A3 is connected to another capacitor C2 and accesses reference voltage Vref 3; the output ends of comparators A1, A2 and A3 are all connected to a logic device group, which outputs the second sampling control signal. Among them, the reference voltage Vref 1 is close to 0V, and Vref 2 is a voltage value higher than Vref 1. Through the design of the technician, the time length of the capacitor C1 voltage rising from Vref 1 to Vref 2 is less than the time length of the first sampling control signal; and the time length of the capacitor C2 voltage reaching Vref 3 from the initial value (such as 0v) is greater than the time length of a first sampling control signal. Initially, the capacitor discharging controller CDC1 shorts the capacitor C1 and the capacitor charging controller CCC1 is disconnected, so that the capacitor C1 is in a zero charge state, at the same time, the capacitor discharging controller CDC2 connected with the capacitor C2 is disconnected and the capacitor charging controller CCC2 is turned on, so that the capacitor C2 is in a state of storing charge; correspondingly, the comparators A1 and A2 output low level, and the comparator A3 outputs high level; when the capacitor charging controller CCC1 connected with the capacitor C1 receives the first sampling control signal, the capacitor charging controller CCC1 connected with the capacitor C1 is turned on and the capacitor discharging controller CDC1 is disconnected, so that the capacitor is charged, when the capacitor voltage is higher than the reference voltage Vref, the comparator A1 outputs high level and the comparator A2 still outputs low level, and the logic device group outputs the second sampling control signal according to the preset logic configuration when the comparators A1 and A3 output high level and the comparator A2 outputs low level. At this time, the capacitor discharging controller CDC2 and the capacitor charging controller CCC2 are controlled by the second sampling control signal to discharge the capacitor C2, and the comparator A3 outputs low level; however, when the capacitor C1 continues to charge so that the voltage reaches Vref 2, the comparator A2 jumps to high level, and the logic device group no longer outputs the second sampling control signal according to the logic configuration when the comparators A1 and A2 both output high level and the comparator A3 outputs low level, and controls the capacitor charging controller CCC1 to be disconnected to make the capacitor C1 no longer charge, and controls the capacitor discharging controller CDC1 to be turned on to discharge the capacitor C1 charge.When the capacitor C1 discharges, the capacitor C2 capacitor charging controller CCC2 is turned on and the capacitor discharge controller CDC2 is turned off, so that the capacitor C2 is charged until the capacitor C2 voltage reaches Vref 3, the comparator A3 outputs high level, and the logic device group outputs the second sampling control signal according to the level change of the comparators A1 and A2 according to the logic configuration when the comparator A3 outputs high level.

[0183] It should be noted that the circuit structure provided by the timing circuit module described above is only an example and is not a limitation of the circuit structure of the timing circuit module in the present application. In fact, according to the design of the timing logic by the skilled person, other timing circuit modules containing comparators, logic device groups, capacitors, or timing circuit modules containing clock signal generators and counters can also be proposed. Herein, detailed description is not made, however, the timing circuit modules designed based on the technical inspiration of the above-mentioned timing circuit modules should be considered as specific examples of the present application. In addition, the devices in the above-mentioned timing circuit module can be fixedly arranged in the chip. In order to facilitate the various types of alternating current cycles provided by different alternating current power supplies, the devices used for timing in the above-mentioned timing circuit module, such as capacitors and their peripheral devices, or counters, etc. can be arranged outside the chip where the leakage protection circuit is located, and these devices are controlled and data is obtained through corresponding pins, so as to facilitate the selection of the skilled person according to the specific design needs. Based on the design of the above-mentioned timing circuit modules, an example is that the sampling unit in the leakage protection circuit samples the voltage of the power supply line during receiving the second sampling control signal.

[0184] It should also be noted that the logic device group mentioned in any of the above examples can contain at least one logic device according to the actual logic design needs, and the corresponding logic configuration can be realized by electrically connecting each logic device. Among them, the logic device includes but is not limited to AND gate, OR gate, NAND gate, NOT gate, encoder, decoder, selector, etc.

[0185] The sampling unit is connected with the detection unit, and is used for obtaining the sampling electric signal of the power supply line based on the received sampling control signal.

[0186] Please refer to Figure 8Fig. 1 shows a schematic diagram of the structure of the leakage protection circuit in one embodiment. As shown in the figure, the sampling unit 12 comprises a controlled switch and a sampling resistor, wherein the control terminal of the controlled switch is connected to the output terminal of the detection unit, one access terminal of the controlled switch is connected to the power supply circuit, and the other access terminal is connected to the ground through the sampling resistor, and the sampling resistor is also connected to the control unit 13. The controlled switch comprises, but is not limited to, any one of the following: a bipolar transistor (BJT), a junction field effect transistor (JFET), a depletion MOS power tube, a silicon-controlled dimmer, etc. When the detection unit 13 outputs a sampling control signal, the controlled switch is turned on, and the control unit 13 obtains the voltage of the sampled electrical signal from the sampling resistor.

[0187] In a specific example, as shown in Fig. 2, the controlled switch is exemplified by a MOS power tube, the gate of the MOS power tube is connected to the output terminal of the timing circuit module, the drain of the MOS power tube is connected to the power supply circuit, and the source is connected to the sampling resistor. According to the foregoing timing circuit module, the MOS power tube is turned on during the reception of the first sampling control signal or the second sampling control signal so that the control unit obtains the sampled voltage. Figure 8

[0188] The control unit is used to compare the voltage of the sampled electrical signal with the preset power-off protection voltage threshold and provide leakage protection based on the comparison result.

[0189] Here, the power-off protection voltage threshold preset by the control unit can be provided by a constant voltage circuit. The power-off protection voltage threshold can be designed based on the voltage drop of the sampling unit affected by the human body voltage division of alternating current. When the control unit determines that the sampled voltage is lower than the power-off protection voltage threshold, the power supply circuit can be disconnected or a leakage protection control signal can be output; otherwise, the power supply loop of the power supply circuit is turned on to make the load work normally.

[0190] In one embodiment, the control unit comprises a comparison circuit module, a logic latch circuit module, and a switching circuit module. The comparison circuit module is used to compare the voltage of the sampled electrical signal with the preset power-off protection voltage threshold and output the comparison result. The logic latch circuit module is connected to the comparison circuit module and is used to latch the comparison result. The switching circuit module is connected to the logic latch circuit module and is used to control the power supply circuit to be turned on or disconnected based on the latched signal.

[0191] Please refer to Fig. 3, which shows the corresponding Figure 9 Figure 8 ​​The waveforms of the sampling voltage received by the comparison circuit module are shown in the leakage protection circuit. As shown in the figure, when the load is connected to the power supply line and there is no human error, the sampled voltage is higher than the power-off protection voltage threshold Vref; when the load is connected to the power supply line and there is human error, the sampled voltage is lower than the power-off protection voltage threshold Vref due to the voltage division of the human body. When the sampled voltage is higher than the power-off protection voltage threshold Vref, the comparison circuit module outputs a jump signal, the logic latch circuit module latches the jump signal and outputs a latch signal to the switch circuit module, and the switch circuit module controls the power supply line to be turned on. Otherwise, the comparison circuit module does not output a jump signal, the logic latch circuit module does not output a latch signal, and the switch circuit module maintains the power supply line to be turned off. Thus, the load and personal safety are protected.

[0192] In a specific example, the comparison circuit module includes a comparator, and the switch circuit module includes a controlled switch and a switch drive module. The negative input terminal of the comparator is connected to the power-off protection voltage threshold, the positive input terminal is connected to the input terminal of the logic latch circuit module, and the output terminal of the logic latch circuit module is the output terminal of the detection unit. The switch circuit module includes a gate drive module and a MOS power tube, for example. The gate of the MOS power tube is connected to the output terminal of the comparator through the gate drive module, and the source and drain are connected to the power supply line. When the load is normally connected to the power supply line, the comparator always outputs a high level, and the MOS power tube turns on the power supply line to make the load work normally. Please refer to Figure 8 The logic latch circuit module latches the high level state when the output of the comparison circuit module jumps from low level to high level, and latches the low level state when the output of the comparison circuit module jumps from high level to low level. Initially, the logic latch circuit module is in low level state, and the switch circuit module disconnects the power supply line based on the received low level state latch signal. When the output of the comparison circuit module jumps from low level to high level, the logic latch circuit module latches the high level state and outputs a high level state latch signal, and the switch circuit module connects the power supply line. Therefore, the latch signal is used to represent the leakage protection control signal of the leakage protection circuit.

[0193] Here, the MOS power tube in the controlled switch can also be replaced by any one of a triode (BJT), a junction field effect transistor (JFET), a depletion MOS power tube, a silicon light dimmer, etc. The switch drive module is not necessarily a gate drive module, but can be adjusted according to actual design needs. For example, the switch circuit module includes a MOS power tube and a source drive module, etc.

[0194] In yet some embodiments, the output of the logic latching circuit module is connected to other circuits (such as the aforementioned driving circuit, etc.) on the power supply line, so that the other circuits provide corresponding leakage protection based on the latching signal. Details are not repeated here.

[0195] It should be noted that the comparison relationship between the sampling electrical signal voltage with human body voltage and the leakage protection voltage threshold value shown in the above Figure 9 , and the comparison relationship between the sampling electrical signal voltage without human body voltage and the leakage protection voltage threshold value are related to the circuit structure of the sampling unit. When the circuit structure of the sampling unit is configured such that the sampled electrical signal voltage with human body voltage is higher than the sampled electrical signal voltage without human body voltage, the corresponding control unit should provide corresponding leakage protection based on the opposite comparison result shown in Figure 9 . The connection mode of the circuit structure of the sampling unit can also be that one access end of the controlled switch is connected to the power supply line through a sampling resistor, and the other access end is grounded. Details are not listed here.

[0196] To prevent the logic latching circuit module from providing false latching signals in the restart operation of the user after turning off the load, the logic latching circuit module needs to be reset to the initial low state when the load is powered off. In some specific examples, the logic latching circuit module is reset based on the fact that the leakage protection circuit is in an underpower state.

[0197] The underpower state is a state in which the power supply of the load cannot reach its working voltage due to external factors or electrical components on the power supply line during normal operation of the load, thereby causing the load to stop working. The underpower state of the leakage protection circuit can be caused by human power-off or by abnormality of internal (or external) electrical components of the leakage protection circuit. For example, situations that cause the leakage protection circuit to be in an underpower state include but are not limited to: the off state of the leakage protection circuit during power-off; and the state of the leakage protection circuit during which the power supply system cannot provide corresponding working voltage to the active devices in the leakage protection circuit.

[0198] The logic circuit module can reset its latched signal by detecting the under-voltage state of the leakage protection circuit. In one embodiment, the reset terminal of the logic latch circuit module is connected to the power supply line. When the power supply line is disconnected, the leakage protection circuit is in an under-voltage state, and the reset terminal receives a valid reset signal. In another embodiment, the reset terminal of the logic latch circuit module is connected to an under-voltage protection circuit for protecting the leakage protection circuit. When the under-voltage protection circuit generates an under-voltage protection signal due to detecting the under-voltage state of the leakage protection circuit, the reset terminal of the logic latch circuit module uses the under-voltage protection signal as the valid reset signal. Thus, the reset operation of the logic latch circuit module is realized.

[0199] In addition, due to the configuration of the logic latch circuit module, when the power supply line is connected, the detection unit and the sampling unit do not necessarily need to continuously provide the voltage of the electrical signal to continuously control the switch circuit unit to be turned on. Therefore, the interval sampling of the power supply line is stopped when the power supply line is controlled to be turned on. The leakage protection circuit can include a control circuit module in the detection unit or the sampling unit to correspondingly stop detection or sampling. In some embodiments, the control unit is also connected to the detection unit to control the detection unit to stop outputting the sampling control signal when the power supply line is controlled to be turned on. For example, the timing circuit module in the detection unit is also connected to the output terminal of the logic latch circuit module in the control unit, and when the logic latch circuit module outputs a high-level state latched signal, the timing circuit module does not output the first sampling control signal or the second sampling control signal. Thus, the problem of false power-off of the load caused by unstable voltage of the alternating current input power supply can be effectively prevented.

[0200] When the power supply line is turned on, the drive circuit in the drive device provides constant current power supply to the load based on the current rectified by the rectifier circuit. Here, one end of the drive circuit is connected to the intersection node of the leakage protection circuit and the rectifier circuit, and the drive circuit provides constant current output to the load by performing constant voltage processing on the received power supply, and then returns to the ground part controlled by the leakage protection circuit to realize a complete loop of the power supply line.

[0201] In some embodiments, the drive circuit uses the resonance principle to process the rectified current into constant current power supply. Here, the drive circuit includes an LC oscillation unit and a switch control unit for controlling the LC oscillation unit. The switch control unit switches the on and off of the oscillation loop in the LC oscillation unit to provide constant current power supply to the load.

[0202] In some other embodiments, the driving circuit provides constant current power supply to the load. In this case, the driving circuit comprises a line voltage compensation circuit. The line voltage compensation circuit compensates the rectified current in reverse direction by preset at least one linear compensation relationship, so that the current flowing through the load is compensated, thereby realizing constant current power supply.

[0203] It should be noted that the driving mode and circuit structure of the driving circuit described above are only examples and not limiting to the present application. For actual driving load, the skilled person can use corresponding driving circuit. Here, no further examples are given. However, any way of connecting the driving circuit with the leakage protection circuit and the rectifier circuit and providing constant current power supply to the load should be considered as a specific example of the present application.

[0204] It should also be noted that all or part of the electrical devices in the driving circuit described above can be integrated in a chip and connected with the leakage protection circuit, the rectifier circuit, the load and other peripheral circuits through pins. The peripheral circuits include but are not limited to the electrical devices not integrated in the driving circuit, the power supply circuit of the chip, etc. For example, the switch control unit in the driving circuit is integrated in the constant current controller of our company. The DRAIN pin of the chip in this series can be used to connect the connection node of the leakage protection circuit and the rectifier circuit, the GND pin is used to connect the switch circuit module in the leakage protection circuit, and the CS pin is used to connect the LC oscillation unit. Please refer to Figure 13

[0205] ​In addition, all or part of the leakage protection circuit and the driving circuit in the driving device can be integrated in a driving chip. The driving chip is connected to the rectifier circuit, the leakage protection circuit, and other peripheral circuits through pins, for leakage detection and driving processing of the current rectified by the rectifier circuit, to provide leakage protection for users and constant current supply for loads. The peripheral circuits include, for example, a power supply circuit of the chip.

[0206] In one example, the driving chip can include the following pins: HV, GND, DRAIN, CS, VCC, etc. The HV pin is connected to the power supply circuit of the rectifier circuit, and the DRAIN and GND pins are connected to the ground circuit of the power supply circuit, so that the conduction or disconnection of the ground circuit of the power supply circuit is controlled by the driving chip. The leakage protection circuit in the driving chip detects the voltage of the power supply circuit through interval sampling of the HV pin, determines whether the voltage of the alternating current input power is divided based on the detected voltage of the sampled electrical signal, and controls the conduction or disconnection of the circuit between the DRAIN and GND pins based on the determined result, thereby achieving leakage protection. When the DRAIN and GND pins in the driving chip are conductive, the driving circuit in the driving chip samples the rectified electrical signal through the CS port and achieves constant current supply for the load based on the detection of the sampled electrical signal. In addition, the VCC pin can be used to connect a constant voltage source of the chip to provide power supply for active devices in the chip and a stable reference voltage for electrical devices such as comparators and operational amplifiers in the chip.

[0207] In another example, according to the actual design requirements of the peripheral circuits of the chip and other circuits in the driving device where the chip is located, the chip can further include a pin for outputting a leakage protection control signal. The leakage protection control signal is generated and outputted by the leakage protection circuit when leakage is detected through interval sampling and voltage division. Other circuits on the power supply circuit can give corresponding leakage protection response based on the received leakage protection control signal. The other circuits include, but are not limited to, filter circuits and driving circuits, etc. For example, as shown in Figure 16 When the leakage protection control signal is received, the enable control unit controls the switch devices or logic devices in the driving circuit to be disconnected, so that the energy converted by the driving circuit cannot be provided to the load, until the leakage protection control signal is disabled and the enable control unit is turned on, at which time the driving circuit can perform driving operation. For another example, as shown in Figure 17As shown, the driving chip comprises a new enable control unit and the circuit in the existing constant current controller, the control end of the enable control unit is connected with the output end of the leakage protection circuit, the input end is connected with the power supply end of the driving chip, and the output end is grounded; when the leakage protection circuit outputs a leakage protection control signal, the enable control unit gives a corresponding leakage protection response based on the leakage protection control signal, that is, the power supply end VCC in the existing constant current controller is grounded, so that the active device in the circuit in the existing constant current controller cannot reach its working voltage.

[0208] It should be noted that the above-mentioned existing constant current controller is only an example, not a limitation of the present application. Those skilled in the art can add a corresponding enable control unit to other driving chips that are not configured with leakage protection, based on the inspiration of the connection relationship between the above-mentioned enable control unit and the chip, so as to realize leakage protection by cooperation of the leakage protection circuit and the driving circuit.

[0209] It should be noted that the number of pins of the driving chip is related to the integrated circuit module, for example, some capacitor devices in the driving circuit are not integrated in the driving chip, and the corresponding driving chip provides pins for connecting the corresponding electrical devices, etc.

[0210] Please refer to Figure 14 , which shows a flowchart of a leakage protection method. The leakage protection method can be performed by the above-mentioned leakage protection circuit, or other leakage protection circuits that can perform the method.

[0211] In step S110, the power supply line of the load is sampled at intervals.

[0212] Here, the sampling interval can be set based on the voltage variation period in the power supply line. For example, the voltage peak or valley of each or interval at least one voltage variation period after rectification is sampled, or the fixed voltage region between the voltage peak and valley in each or interval at least one voltage variation period after rectification is sampled. In order to ensure that the human body will not be injured by continuous electric shock when touched by mistake, the sampling interval is in the order of milliseconds or even microseconds. For example, the sampling interval can be interval half a voltage variation period, interval one voltage variation period, or interval multiple voltage variation periods. The sampling interval can be realized by the circuit structure designed by the leakage protection circuit using the voltage variation period. Alternatively, the sampling interval is set according to the pre-set time length. For example, the leakage protection circuit comprises a capacitor and a resistor, and the sampling interval is determined by the charging time of the capacitor; wherein, the skilled person can design the corresponding sampling interval by configuring the resistor. The resistor can be an adjustable resistor or a fixed resistor.

[0213] In some embodiments, the voltage of the electrical signal can be sampled at intervals set according to a voltage variation period, and whether the voltage of the AC input power is divided can be determined by comparing the voltage of the electrical signal with a preset power-off protection voltage threshold.

[0214] To this end, the step S110 can comprise a step of obtaining a sampling electrical signal of the power supply line based on the detection of the voltage of the power supply line and based on the result of the voltage limiting detection.

[0215] Here, the leakage protection circuit can detect the voltage variation on the power supply line in real time, and determine that the sampling interval for obtaining the sampling electrical signal of the power supply line is reached when the voltage variation is detected to reach a preset reference voltage value. The preset reference voltage value can correspond to any voltage value in the voltage variation period, such as a peak value, a valley value, an intermediate value, etc.

[0216] In some embodiments, the leakage protection circuit detects the voltage of the power supply line, and obtains the sampling electrical signal of the power supply line when the detected voltage falls within a preset voltage limiting interval. The voltage limiting interval is intercepted within the voltage variation range of the power supply line. For example, the voltage limiting interval is [V1, V2], where 0≤V1<V2<Vmax, and Vmax is the maximum value of the voltage variation range. The leakage protection circuit can perform a sampling action once every voltage variation period.

[0217] In yet some embodiments, the leakage protection circuit further obtains the sampling electrical signal of the power supply line within a limited time when the detected voltage falls within the preset voltage limiting interval. The limited sampling time is shorter than the time length during which the detected voltage falls within the preset voltage limiting interval. Limiting the sampling time can effectively prevent the mis-triggering operation caused by the jitter of the sampled electrical signal. For example, refer to Figure 4 The leakage protection circuit samples the electrical signal of the power supply line within the effective time limit of the second sampling control signal. The first sampling control signal is generated when the voltage of the power supply line is detected to fall within the preset voltage limiting interval, and the second sampling control signal is a signal generated within a limited time when the first sampling control signal is generated. The leakage protection circuit samples the electrical signal based on the second sampling control signal.

[0218] In some embodiments, the leakage protection circuit collects the sampling electrical signal of the power supply line within the voltage limiting interval at intervals set according to a preset detection timing. For example, refer to Figure 6, which shows a waveform diagram of the relationship between the second sampling control signal and the first sampling control signal in the leakage protection circuit. As shown in the figure, the detection timing can be such that the timing circuit module does not output the second sampling control signal based on the first sampling control signal within the time interval T2 of at least one first sampling control signal. The leakage protection circuit obtains the sampled electrical signal of the power supply line within the duration of the second sampling control signal.

[0219] In step S120, the voltage of the sampled electrical signal is detected to determine whether the voltage of the AC input source is divided.

[0220] Here, the leakage protection circuit can determine whether the voltage of the AC input source is divided by comparing the sampling voltage corresponding to the sampling time with the preset reference voltage corresponding to the sampling time, thereby determining whether to turn on the power supply line where the load is located. For example, the leakage protection circuit starts timing of the sampling interval by detecting the voltage zero point on the power supply line, samples the electrical signal on the power supply line when the timing reaches, and compares the sampled electrical signal voltage with the voltage threshold value at the timing reaching time according to the voltage variation period of the power supply line to determine whether the voltage of the AC input source is divided.

[0221] In some embodiments, the leakage protection circuit presets a power-off protection voltage threshold. The power-off protection voltage threshold can be designed based on the voltage drop affecting the sampling unit due to the human body dividing the AC voltage. The leakage protection circuit compares the voltage of the sampled electrical signal with the preset power-off protection voltage threshold and outputs the comparison result. For example, when the load is normally connected to the power supply line, the sampled voltage is higher than the power-off protection voltage threshold; when the load is connected to the power supply line and there is human error, the sampled voltage is lower than the power-off protection voltage threshold due to the human body voltage division.

[0222] It should be noted that according to the circuit structure design of the sampling unit, when the load is normally connected to the power supply line, the sampled voltage can be lower than the power-off protection voltage threshold; when the load is connected to the power supply line and there is human error, the sampled voltage is higher than the power-off protection voltage threshold due to the human body voltage division.

[0223] In step S130, leakage protection is provided based on the detected result.

[0224] In some embodiments, the leakage protection circuit compares the voltage of the sampled electrical signal with the preset power-off protection voltage threshold; when the comparison result is that the voltage of the AC input source is not divided, the power supply line is controlled to be turned on; and when the detected result is that the voltage of the AC input source is not divided, the power supply line is controlled to be disconnected.

[0225] In one embodiment, the leakage protection circuit comprises a controlled switch connected to the power supply line. The controlled switch is exemplified as a MOS power transistor. The leakage protection circuit controls the MOS power transistor to be on when the voltage of the electrical signal is higher than or equal to the leakage protection voltage threshold, and vice versa.

[0226] In another embodiment, the leakage protection circuit outputs a leakage protection control signal to other circuits connected to the power supply line based on the detected result. The leakage protection control signal is generated and outputted by the leakage protection circuit when leakage is detected after the voltage of the electrical signal is sampled and divided. The other circuits can give corresponding leakage protection response based on the received leakage protection control signal. The other circuits include but are not limited to filter circuits and driving circuits. For example, the driving circuit connected to the leakage protection circuit comprises an enable control unit (not shown) whose control end (i.e. enable end EN) is connected to the output end of the leakage protection circuit and controls the switching devices or logic devices in the driving circuit. When the enable control unit receives the leakage protection control signal, it controls the switching devices in the driving circuit to be off, so that the energy converted by the driving circuit cannot be provided to the load, until the leakage protection control signal is disabled and the driving circuit can perform driving operation. For another example, the driving circuit connected to the leakage protection circuit comprises an enable control unit and an existing constant current controller. The control end of the enable control unit is connected to the output end of the leakage protection circuit, the input end is connected to the power supply end of the driving chip, and the output end is grounded. When the leakage protection circuit outputs the leakage protection control signal, the enable control unit gives corresponding leakage protection response based on the leakage protection control signal, i.e. grounds the power supply end VCC of the existing constant current controller, so that the active devices in the existing constant current controller cannot reach their working voltage.

[0227] In another embodiment, the leakage protection method further comprises the step of stopping the sampling of the power supply line when the power supply line is controlled to be on.

[0228] Since the leakage protection circuit does not necessarily need to continue to sample the voltage of the electrical signal to control the switching circuit unit to be on when the power supply line is connected, the leakage protection circuit can stop generating the sampling control signal or stop sampling when the power supply line is on.

[0229] It should be noted that the above steps can be performed by the corresponding circuit modules of the leakage protection circuit mentioned in the present application, and the structure of the leakage protection circuit will not be repeated here.

[0230] Please refer to Figure 15The flow chart shows the driving method in an embodiment of the present application. The driving method is mainly executed by the driving device mentioned above or other driving device capable of executing the method.

[0231] In step S210, the accessed AC power is rectified and provided to the power supply line of the load.

[0232] Here, the driving device accesses the AC input source and rectifies the output by a rectifier bridge composed of four diodes.

[0233] In step S220, the power supply line is sampled at intervals. The implementation of step S220 can be the same as or similar to the implementation of step S110 mentioned above, which will not be described in detail here.

[0234] For example, the leakage protection circuit in the driving device collects the sampled electrical signal on the power supply line within the voltage limiting interval at preset detection timing intervals. Please refer to Figure 6 The waveform diagram shows the relationship between the second sampling control signal and the first sampling control signal in the leakage protection circuit. As shown in the figure, the detection timing can be such that the timing circuit module does not generate the second sampling control signal based on the first sampling control signal within the time interval T2 of at least one first sampling control signal. The first sampling control signal is generated when the voltage of the power supply line is detected to fall within the preset voltage limiting interval, and the second sampling control signal is a signal generated in a limited time when the first sampling control signal is generated. The leakage protection circuit acquires the sampled electrical signal of the power supply line within the duration of the second sampling control signal.

[0235] In step S230, the voltage of the sampled electrical signal is detected to determine whether the voltage of the AC input source is divided. The implementation of step S230 can be the same as or similar to the implementation of step S120 mentioned above, which will not be described in detail here.

[0236] For example, the leakage protection circuit in the driving device presets a power-off protection voltage threshold. The power-off protection voltage threshold can be designed based on the voltage drop affecting the sampling unit due to the human body dividing the AC power. The leakage protection circuit compares the voltage of the sampled electrical signal with the preset power-off protection voltage threshold and outputs the comparison result. When the load is normally connected to the power supply line, the sampled voltage is higher than the power-off protection voltage threshold; when the load is connected to the power supply line and there is human error, the sampled voltage is lower than the power-off protection voltage threshold due to the human body dividing the voltage.

[0237] In step S240, leakage protection is provided based on the detected result. The implementation of step S240 can be the same as or similar to the implementation of step S130 mentioned above, which will not be described in detail here.

[0238] For example, the leakage protection circuit in the driving device comprises a controlled switch connected to the power supply line. The controlled switch is exemplified as a MOS power tube. When the voltage of the electrical signal is higher than or equal to the power-off protection voltage threshold, the leakage protection circuit controls the MOS power tube to be turned on and performs step S250. Otherwise, the leakage protection circuit controls the MOS power tube to be turned off to provide leakage protection.

[0239] In step S250, power supply is provided to the load on the power supply line.

[0240] For example, the driving circuit in the driving device uses the resonance principle to process the rectified current into the working power supply of the load. For another example, the driving circuit in the driving device uses the line voltage compensation method to process the rectified current into the working power supply of the load.

[0241] In summary, the present application determines whether the accessed AC input power is divided by sampling and dividing the voltage in the power supply line to determine whether the accessed AC input power is divided. When it is determined that the AC input power is divided, the power supply line is turned off, thereby achieving leakage protection for the accidental touch of the human body and the load.

[0242] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea of the present application should be covered by the claims of the present application.

Claims

1. An electric leakage protection circuit, characterized by comprising: A power supply line for electrically connecting a load, the power supply line is periodically sampled, a voltage of the sampled electrical signal is detected to determine whether a voltage of an alternating input power supply is divided, and leakage protection is provided based on the determined result; The leakage protection circuit comprises: A detection unit connected to the power supply line, configured to output a sampling control signal based on the detection of the voltage of the power supply line, the detection unit comprises a voltage limiting detection circuit module connected to the power supply line, the voltage limiting detection circuit module is configured to detect the voltage of the power supply line and output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval, the preset voltage limiting interval is intercepted within the voltage variation range of the power supply line; A sampling unit connected to the detection unit, configured to obtain a sampled electrical signal of the power supply line based on the received sampling control signal; A control unit connected to the sampling unit, configured to compare the voltage of the sampled electrical signal with a preset power-off protection voltage threshold, and provide leakage protection based on the comparison result.

2. The ground-fault circuit of claim 1, wherein, The detection unit further comprises a timing circuit module connected to the voltage limiting detection circuit module, configured to limit the output of a second sampling control signal based on the first sampling control signal.

3. The ground-fault circuit of claim 2, wherein, The timing circuit module sets a detection timing based on the first sampling control signal, and outputs the second sampling control signal after the detection timing expires.

4. The leakage protection circuit according to claim 2 or 3, characterized in that, The timing circuit module outputs the second sampling control signal within the duration of the first sampling control signal.

5. The ground-fault circuit of claim 1, wherein, The control unit comprises: A comparison circuit module configured to compare the voltage of the sampled electrical signal with a preset power-off protection voltage threshold and output a comparison result; A logic latch circuit module connected to the comparison circuit module, configured to latch the comparison result and output a corresponding latch signal; wherein the latch signal is used to represent a leakage protection control signal of the leakage protection circuit.

6. The ground-fault circuit of claim 5, wherein, The control unit further comprises a switch circuit module connected to the logic latch circuit module, configured to control the power supply line to be turned on or turned off based on the latch signal.

7. The ground fault protection circuit of claim 5, wherein, The logic latch circuit module is reset based on the leakage protection circuit being in an underpower state.

8. The ground fault protection circuit of claim 6, wherein, The periodic sampling of the power supply line is stopped when the power supply line is controlled to be turned on.

9. The ground fault protection circuit of claim 1, wherein, The control unit is further connected to the detection unit, configured to control the detection unit to stop outputting the sampling control signal when the power supply line is controlled to be turned on.

10. The ground fault protection circuit of claim 1, wherein, The leakage protection circuit is an LED leakage protection circuit, configured to be electrically connected to a power supply line of an LED load, and the LED leakage protection circuit outputs a leakage protection control signal based on the determined comparison result so that an LED driving circuit electrically connected thereto gives a corresponding leakage protection response based on the leakage protection control signal.

11. A chip, characterized by Comprises: A plurality of pins, wherein at least one pin is electrically connected to a power supply line of a load; The leakage protection circuit is connected with the pin and is used for interval sampling of the power supply circuit, detecting voltage of the sampled electric signal to determine whether voltage of the alternating current input power supply is divided, and providing leakage protection based on the determined result; the leakage protection circuit comprises: a detection unit connected with the power supply circuit and used for outputting a sampling control signal based on detection of voltage of the power supply circuit, the detection unit comprising a voltage limiting detection circuit module connected with the power supply circuit, the voltage limiting detection circuit module being used for detecting voltage of the power supply circuit and outputting a first sampling control signal when the detected voltage falls into a preset voltage limiting interval, the preset voltage limiting interval being intercepted in a voltage variation range of the power supply circuit; a sampling unit connected with the detection unit and used for acquiring a sampling electric signal of the power supply circuit based on the received sampling control signal; and a control unit connected with the sampling unit and used for comparing voltage of the sampling electric signal with a preset power-off protection voltage threshold and providing leakage protection based on a comparison result.

12. The chip of claim 11, wherein, The detection unit further comprises a timing circuit module connected with the voltage limiting detection circuit module and used for time-limited output of a second sampling control signal based on the first sampling control signal.

13. The chip of claim 12, wherein, The timing circuit module sets a detection timing based on the first sampling control signal and outputs the second sampling control signal after the detection timing expires.

14. The chip according to claim 12 or 13, characterized in that The timing circuit module outputs the second sampling control signal within a duration of the first sampling control signal.

15. The chip of claim 11, wherein, The control unit comprises: a comparison circuit module used for comparing voltage of the sampled electric signal with the preset power-off protection voltage threshold and outputting a comparison result; a logic latch circuit module connected with the comparison circuit module and used for latching the comparison result and outputting a corresponding latch signal; wherein the latch signal is used for indicating a leakage protection control signal of the leakage protection circuit.

16. The chip of claim 15, wherein, The control unit further comprises a switch circuit module connected with the logic latch circuit module and used for controlling the power supply circuit to be turned on or turned off based on the latch signal.

17. The chip of claim 15, wherein, The logic latch circuit module is reset based on the leakage protection circuit being in an underpower state.

18. The chip of claim 11, wherein, The leakage protection circuit outputs a leakage protection control signal based on the determined result; and the chip further comprises a pin used for outputting the leakage protection control signal, so that a driving circuit connected with the pin gives a corresponding leakage protection response based on the leakage protection control signal.

19. The chip of claim 16, wherein, The leakage protection circuit stops interval sampling of the power supply circuit when the power supply circuit is controlled to be turned on.

20. The chip of claim 11, wherein, The control unit is further connected with the detection unit and is used for controlling the detection unit to stop outputting the sampling control signal when the power supply circuit is controlled to be turned on.

21. The chip of claim 11, wherein, The leakage protection circuit is an LED leakage protection circuit and is electrically connected with a power supply circuit of an LED load through the pin.

22. A drive apparatus characterized by comprising: The chip comprises: a rectifier circuit used for rectifying alternating current accessed and providing the rectified alternating current to a power supply circuit of a load; and The leakage protection circuit is connected to the rectifier circuit and is configured to perform interval sampling on the power supply line, detect voltage of the sampled electrical signal to determine whether voltage of the AC input power is divided, and provide leakage protection based on the determined result; The driving circuit is connected to the leakage protection circuit and is configured to supply power to the load based on the current rectified by the rectifier circuit; The leakage protection circuit comprises a detection unit connected to the power supply line and configured to output a sampling control signal based on detection of voltage of the power supply line, the detection unit comprising a voltage limiting detection circuit module connected to the power supply line, the voltage limiting detection circuit module being configured to detect voltage of the power supply line and output a first sampling control signal when the detected voltage falls within a preset voltage limiting interval, the preset voltage limiting interval being intercepted within a voltage variation range of the power supply line; a sampling unit connected to the detection unit and configured to obtain a sampled electrical signal of the power supply line based on the received sampling control signal; and a control unit connected to the sampling unit and configured to compare voltage of the sampled electrical signal with a preset power-off protection voltage threshold and provide leakage protection based on a comparison result.

23. The drive apparatus according to claim 22, characterized by The detection unit further comprises a timing circuit module connected to the voltage limiting detection circuit module and configured to output a second sampling control signal based on the first sampling control signal.

24. The drive apparatus according to claim 23, characterized by The timing circuit module sets a detection timing based on the first sampling control signal and outputs the second sampling control signal after the detection timing expires.

25. Drive arrangement according to claim 23 or 24, characterized in that The timing circuit module outputs the second sampling control signal within a duration of the first sampling control signal.

26. The drive apparatus of claim 22, wherein The control unit comprises a comparison circuit module configured to compare voltage of the sampled electrical signal with the preset power-off protection voltage threshold and output a comparison result; and a logic latch circuit module connected to the comparison circuit module and configured to latch the comparison result and output a corresponding latch signal, wherein the latch signal is used to represent a leakage protection control signal of the leakage protection circuit.

27. The drive apparatus according to claim 26, wherein The control unit further comprises a switch circuit module connected to the logic latch circuit module and configured to control the power supply line to be turned on or turned off based on the latch signal.

28. The drive apparatus of claim 26, wherein The logic latch circuit module is reset based on the leakage protection circuit being in an underpower state.

29. The drive apparatus of claim 22, wherein The leakage protection circuit outputs a leakage protection control signal to the driving circuit, and the driving circuit gives a corresponding leakage protection response based on the leakage protection control signal.

30. The drive apparatus according to claim 29, wherein The driving circuit comprises an enable control unit, which gives a corresponding leakage protection response based on the leakage protection control signal when the leakage protection circuit outputs the leakage protection control signal.

31. The drive apparatus according to claim 27, wherein The leakage protection circuit stops interval sampling on the power supply line when the power supply line is controlled to be turned on.

32. The drive apparatus of claim 22, wherein The control unit is further connected to the detection unit and is configured to control the detection unit to stop outputting the sampling control signal when the power supply line is controlled to be turned on.

33. The drive apparatus of claim 22, wherein The driving device is an LED driving device.

34. A driver chip, comprising: Comprises: A plurality of pins, wherein at least two pins are used to electrically connect the power supply line of the load; The leakage protection circuit is connected with the pin and is used for sampling the power supply line at intervals, detecting the voltage of the sampled electric signal to determine whether the voltage of the alternating current input power supply is divided, and providing leakage protection based on the determined result; The driving circuit is connected with the leakage protection circuit and is used for supplying power to the load based on the current rectified by the rectifier circuit; The leakage protection circuit comprises a detection unit connected with the power supply line and used for outputting a sampling control signal based on the detection of the voltage of the power supply line, the detection unit comprising a voltage limiting detection circuit module connected with the power supply line and used for detecting the voltage of the power supply line and outputting a first sampling control signal when the detected voltage falls into a preset voltage limiting interval, the preset voltage limiting interval being intercepted in the voltage variation range of the power supply line; a sampling unit connected with the detection unit and used for obtaining a sampling electric signal of the power supply line based on the received sampling control signal; and a control unit connected with the sampling unit and used for comparing the voltage of the sampling electric signal with a preset power-off protection voltage threshold and providing leakage protection based on the comparison result.

35. The driver chip of claim 34, wherein, The detection unit further comprises a timing circuit module connected with the voltage limiting detection circuit module and used for limiting the output of a second sampling control signal based on the first sampling control signal.

36. The driver chip of claim 35, wherein, The timing circuit module sets a detection timing based on the first sampling control signal and outputs the second sampling control signal after the detection timing expires.

37. The driver chip of claim 35, wherein, The timing circuit module outputs the second sampling control signal within the duration of the first sampling control signal.

38. The driver chip of claim 34, wherein, The control unit comprises a comparison circuit module used for comparing the voltage of the sampling electric signal with the preset power-off protection voltage threshold and outputting a comparison result; and a logic latch circuit module connected with the comparison circuit module and used for latching the comparison result and outputting a corresponding latch signal; wherein the latch signal is used for representing a leakage protection control signal of the leakage protection circuit.

39. The driver chip of claim 38, wherein, The control unit further comprises a switch circuit module connected with the logic latch circuit module and used for controlling the power supply line to be turned on or turned off based on the latch signal.

40. The driver chip of claim 38, wherein, The logic latch circuit module is reset based on the leakage protection circuit being in an underpower state.

41. The driver chip of claim 38, wherein, The leakage protection circuit outputs a leakage protection control signal to the driving circuit; and the driving circuit gives a corresponding leakage protection response based on the leakage protection control signal.

42. The driver chip of claim 41, wherein, The driving circuit comprises an enable control unit, which gives a corresponding leakage protection response based on the leakage protection control signal when the leakage protection circuit outputs the leakage protection control signal.

43. The driver chip of claim 39, wherein, The leakage protection circuit stops sampling the power supply line at intervals when the power supply line is controlled to be turned on.

44. The driver chip of claim 34, wherein, The control unit is further connected with the detection unit and is used for controlling the detection unit to stop outputting the sampling control signal when the power supply line is controlled to be turned on.

45. The driver chip of claim 34, wherein, The driving chip is an LED driving chip.

46. An arc fault protection method, comprising: Comprise: The power supply line of the load is interval sampled, and a sampling control signal is output. The sampling electrical signal of the power supply line is obtained according to the received sampling control signal. The interval sampling includes: detecting the voltage of the power supply line, and outputting a first sampling control signal when the detected voltage falls into a preset voltage limiting interval, which is intercepted in the voltage variation range of the power supply line; The voltage of the sampled electrical signal is detected to determine whether the voltage of the AC input source is divided. The detection of the voltage of the sampled electrical signal includes: comparing the voltage of the sampled electrical signal with a preset power-off protection voltage threshold, and determining whether the voltage of the AC input source is divided based on the comparison result; Leakage protection is provided based on the detected result.

47. The arc fault protection method of claim 46, wherein, The way of providing leakage protection based on the detected result includes: when the detected result is that the voltage of the AC input source is not divided, controlling the power supply line to be turned on; when the detected result is that the voltage of the AC input source is divided, controlling the power supply line to be turned off; or when the detected result is that the voltage of the AC input source is not divided, controlling the driving circuit to supply power to the load; and when the detected result is that the voltage of the AC input source is divided, controlling the driving circuit to give a leakage protection response.

48. The arc fault protection method of claim 46, wherein, Further comprising a step of stopping the interval sampling of the power supply line when the power supply line is controlled to be turned on.

49. A driving method, comprising: It includes: A power supply line of a load is provided with AC power after rectification; The power supply line is interval sampled, and a sampling control signal is output. The sampling electrical signal of the power supply line is obtained according to the received sampling control signal. The interval sampling includes: detecting the voltage of the power supply line, and outputting a first sampling control signal when the detected voltage falls into a preset voltage limiting interval, which is intercepted in the voltage variation range of the power supply line; The voltage of the sampled electrical signal is detected to determine whether the voltage of the AC input source is divided. The detection of the voltage of the sampled electrical signal includes: comparing the voltage of the sampled electrical signal with a preset power-off protection voltage threshold, and determining whether the voltage of the AC input source is divided based on the comparison result; Leakage protection is provided based on the detected result. When it is confirmed that there is no need to provide leakage protection, the load on the power supply line is supplied with power.

50. The driving method according to claim 49, wherein The way of providing leakage protection based on the detected result includes: When the comparison result is that the voltage of the AC input source is not divided, the power supply line is controlled to be turned on; when the comparison result is that the voltage of the AC input source is divided, the power supply line is controlled to be turned off; or When the comparison result is that the voltage of the AC input source is not divided, the driving circuit is controlled to supply power to the load; and when the comparison result is that the voltage of the AC input source is divided, the driving circuit is controlled to give a leakage protection response.

51. The driving method according to claim 50, wherein Further comprising a step of stopping the interval sampling of the power supply line when the power supply line is controlled to be turned on.

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