High-precision surge protection circuit, power supply connecting line, equipment, system and method

Abstract

The invention provides a high-precision surge protection circuit, a power supply connecting line, equipment, a system and a method, a first end of the circuit is coupled to a path between a power supply input end and a power supply output end, a second end of the circuit is grounded, and the circuit compares the magnitude of path voltage with the magnitude of trigger voltage through a surge detection module; only when the comparison result represents that the surge occurs on the access, the power supply module is controlled to supply power to the discharge control module, so that the reference voltage source unit outputs a reference voltage, the comparison unit performs first processing on the reference voltage and the voltage of the second end of the first resistor, and outputs a corresponding first voltage to the control end of the discharge switch; therefore, the conduction degree of the discharge switch is controlled, and the voltage of the output end of the power supply is accurately clamped to a set clamping voltage. And when the comparison result shows that no surge occurs on the path, the power supply module is controlled to stop supplying power to the discharge control module, so that the discharge control module stops working, and the loss generated by the circuit is reduced.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on and claims the priority of application No. CN202410245652.5 filed with the China Patent and Trademark Office on March 5, 2024, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to the field of power electronics technology, and in particular to a high-precision surge protection circuit, a power connection line, an electronic device, a charging system and a high-precision surge protection method. Background Art

[0004] When switching power, electronic devices often generate transient voltages, such as pulse voltage, electrostatic discharge, and surge voltage, etc. Among them, surge voltage has high energy and large overcurrent, which is more harmful to the circuit and easily causes damage to the circuit. The cumulative effect of multiple small surges will also cause the performance of semiconductor devices to decline. Therefore, in order to protect electronic devices from damage during surges, it is necessary to add a surge suppression circuit to the power input port of the electronic device.

[0005] At present, the main surge suppression methods are: inserting appropriate linear impedance into the circuit to suppress the startup surge current (for example, Yao Likun, Yao Fei, Fu Zongbao, etc. Design and application research of space suit surge suppression circuit [J]. Computer Measurement and Control, 2021, 29(03): 220-223. DOI: 10.16526 / j.cnki.11-4762 / tp.2021.03.043.), connecting a specific surge suppression chip in series in the line (for example, CN116054115B), and connecting the TVS device in parallel with the subsequent circuit (for example, Dong Dawei, Li Jiangling. Research and design of a surge protection circuit [J]. Application of Electronic Technology, 2020, 46(07): 74-77. DOI: 10.16157 / j.issn.0258-7998.200395.).

[0006] However, the above existing practices have the following problems:

[0007] 1) For circuits that insert appropriate linear impedance to suppress startup surge current, since the resistance value of the resistor will change due to the influence of process and temperature, it can only be applied to devices with lower ambient temperature requirements;

[0008] 2) For a circuit that has a specific surge suppression chip connected in series in the line, although the internal MOS tube can be driven to work in the subthreshold region to absorb the surge energy when a surge occurs, its on-resistance is large when the circuit is working normally, which will generate unnecessary heat and affect the reliability of the device;

[0009] 3) For the circuit that connects the TVS device in parallel with the subsequent circuit, the cost is relatively high, the junction capacitance of the circuit is large, the clamping (protection) voltage value cannot be designed arbitrarily, and the leakage current generated is relatively large.

[0010] Therefore, how to clamp the output voltage of the control circuit to a set value when a surge voltage occurs, while ensuring that there is no impedance between the input and output ends of the power line, has become a technical problem that urgently needs to be solved in the industry. Summary of the invention

[0011] The present invention provides a high-precision surge protection circuit, a power connection line, an electronic device, a charging system and a high-precision surge protection method to solve the problem of how to clamp the output voltage of the control circuit to a set value when a surge voltage occurs, while taking into account the problem that there is no impedance between the input end and the output end of the power line.

[0012] According to a first aspect of the present invention, a high-precision surge protection circuit is provided, wherein a first end of the circuit is coupled to a power input end and a power output end respectively, and a second end of the circuit is grounded; the high-precision surge protection circuit comprises a surge detection module, a power module, a discharge control module and a discharge switch; the discharge control module comprises a reference voltage source unit, a comparison unit, a first resistor and a second resistor;

[0013] The first end of the surge detection module, the first end of the first resistor and the first end of the discharge switch are respectively coupled to the power input end and the power output end; the second end of the surge detection module is coupled to the input end of the power module, and the third end thereof is grounded; the output end of the power module is respectively coupled to the input end of the reference voltage source unit and the first end of the comparison unit; the output end of the reference voltage source unit is coupled to the first input end of the comparison unit, the second end of the first resistor is respectively coupled to the second input end of the comparison unit and the first end of the second resistor, and the second end of the second resistor is grounded; the output end of the comparison unit is coupled to the control end of the discharge switch, and the second end of the discharge switch is grounded, wherein:

[0014] The surge detection module is used to compare the voltage of the path voltage and the trigger voltage, and only when the comparison result indicates that a surge occurs in the path between the power input end and the power output end, control the power module to supply power to the discharge control module; otherwise, control the power module to stop supplying power to the discharge control module;

[0015] The reference voltage source unit is configured to: output a reference voltage only when the power module supplies power to the discharge control module; otherwise, output a power ground voltage;

[0016] The comparison unit is configured as follows:

[0017] When the power supply module supplies power to the discharge control module, the reference voltage and the voltage at the second end of the first resistor are first processed, and the corresponding first voltage is output to the control end of the discharge switch to control the conduction degree of the discharge switch and clamp the voltage at the power output end to the clamping voltage; the first processing at least includes subtraction amplification processing;

[0018] When the power module stops supplying power to the discharge control module, the power ground voltage is output to the control end of the discharge switch to control the discharge switch to be turned off.

[0019] Optionally, the voltage value of the clamping voltage is configured as:

[0020]

[0021] Among them, V CLAMP is the clamping voltage value, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, V IN+ is the voltage value of the reference voltage.

[0022] Optionally, the comparison unit includes an amplifier, a first PMOS tube, a third resistor and a first pull-down sub-unit;

[0023] The power supply end of the amplifier is coupled to the output end of the power module, the non-inverting input end thereof is coupled to the output end of the reference voltage source unit, the inverting input end thereof is coupled to the second end of the first resistor, the output end thereof is coupled to the control end of the first PMOS tube, the source of the first PMOS tube is coupled to the output end of the power module, the drain thereof is respectively coupled to the first end of the first pull-down sub-unit and the first end of the third resistor, the second end of the first pull-down sub-unit is grounded; the second end of the third resistor is coupled to the control end of the discharge switch to output the corresponding first voltage or the power ground voltage; wherein:

[0024] The amplifier is configured as:

[0025] When the power supply module supplies power to the discharge control module, the voltage value received by the non-inverting input terminal thereof is compared with the voltage value received by the inverting input terminal thereof, and if the voltage value received by the non-inverting input terminal thereof is greater than the voltage value received by the inverting input terminal thereof, the power supply voltage of the power supply module is output;

[0026] If the voltage value received at its non-inverting input terminal is less than or equal to the voltage value received at its inverting input terminal, the reference voltage and the voltage at the second end of the first resistor are subtracted and amplified, and a corresponding second voltage value is output to the control end of the first PMOS tube to control the conduction degree of the first PMOS tube and clamp the voltage at the power output end to the clamping voltage.

[0027] Optionally, the discharge switch is an NMOS tube.

[0028] Optionally, the first pull-down subunit includes a resistor.

[0029] Optionally, the power module includes a second PMOS transistor, a first capacitor, a fifth resistor, a third PMOS transistor, a first NMOS transistor, a second NMOS transistor, a fourth PMOS transistor, a sixth resistor and a first diode;

[0030] The source and gate of the second PMOS tube are both coupled to the second end of the surge detection module, the drain of the second PMOS tube is respectively coupled to the first end of the first capacitor, the first end of the fifth resistor, the gate of the third PMOS tube and the gate of the first NMOS tube, the second end of the first capacitor and the second end of the fifth resistor are both grounded, the source of the third PMOS tube is coupled to the gate of the second PMOS tube, the drain of the third PMOS tube is respectively coupled to the drain of the first NMOS tube and the gate of the fourth PMOS tube, the source of the first NMOS tube is grounded, the source of the fourth PMOS tube is coupled to the source of the second NMOS tube, the drain of the second NMOS tube is coupled to the first end of the surge detection module, and its gate is coupled to the gate of the second PMOS tube, the drain of the fourth PMOS tube is respectively coupled to the first end of the sixth resistor and the negative electrode of the first diode, and the second end of the sixth resistor and the positive electrode of the first diode are both grounded.

[0031] Optionally, the first pull-down subunit includes a pull-down current source.

[0032] Optionally, the comparison unit further includes a second pull-down subunit;

[0033] A first end of the second pull-down subunit is coupled to a second end of the third resistor, and a second end of the second pull-down subunit is grounded.

[0034] Optionally, the second pull-down submodule includes a seventh resistor, a third NMOS transistor and a fourth NMOS transistor;

[0035] The first end of the seventh resistor is coupled to the anode of the first diode, and the second end thereof is respectively coupled to the drain of the third NMOS tube and the gate of the fourth NMOS tube. The gate of the third NMOS tube is coupled to the first end of the fifth resistor, and the source thereof is grounded. The drain of the fourth NMOS tube is coupled to the second end of the third resistor, and the source thereof is grounded.

[0036] Optionally, the surge detection module includes a first zener diode, a second zener diode, a third zener diode, a fourth resistor and a fourth zener diode connected in series in sequence;

[0037] The first end of the first Zener diode is coupled to the power input terminal, the fourth Zener diode is grounded, and the first end and the second end of the fourth resistor are respectively coupled to the first input terminal and the second input terminal of the power module to output the comparison result to the power module.

[0038] Optionally, the trigger voltage is the sum of a Zener voltage of the first Zener diode, a Zener voltage of the second Zener diode, and a Zener voltage of the third Zener diode.

[0039] Optionally, the surge detection module includes at least one voltage regulator diode.

[0040] Optionally, the trigger voltage is greater than the clamping voltage.

[0041] Optionally, the trigger voltage is less than or equal to the clamping voltage.

[0042] Optionally, the power module includes a second capacitor; the second capacitor is connected in parallel with the fourth resistor.

[0043] According to a second aspect of the present invention, there is provided a power connection line for providing a connection between a power supply device and a device for charging, comprising a voltage bus and a high-precision surge protection circuit as described in any one of the first aspects of the present invention connected in parallel to the voltage bus.

[0044] According to a third aspect of the present invention, there is provided an electronic device, comprising the high-precision surge protection circuit provided by any one of the first aspects of the present invention.

[0045] According to a fourth aspect of the present invention, there is provided a charging system, comprising the high-precision surge protection circuit provided by the third aspect of the present invention.

[0046] According to a fifth aspect of the present invention, a high-precision surge protection method is provided, for controlling the high-precision surge protection circuit according to any one of the first aspects of the present invention, the method comprising:

[0047] Compare the voltage magnitudes of the path voltage and the trigger voltage, and only when the comparison result indicates that a surge occurs in the path between the power input terminal and the power output terminal, control the power module to supply power to the discharge control module; otherwise, control the power module to stop supplying power to the discharge control module; wherein:

[0048] If the power module supplies power to the discharge control module, the following steps are performed:

[0049] Controlling the reference voltage source unit to output a reference voltage;

[0050] Performing a first processing on the reference voltage and the voltage at the second end of the first resistor, and outputting a corresponding first voltage to the control end of the discharge switch to control the conduction degree of the discharge switch and clamp the voltage at the power output end to the clamping voltage; the first processing at least includes a subtraction amplification processing;

[0051] If the power module stops supplying power to the discharge control module, the following steps are performed:

[0052] Controlling the reference voltage source unit to output a power ground voltage;

[0053] The power ground voltage is output to the control end of the discharge switch to control the discharge switch to be turned off.

[0054] In the high-precision surge protection circuit, power connection line, electronic device, charging system and high-precision surge protection method provided by the present invention, the first end of the circuit is coupled to the power input end and the power output end respectively, and the second end thereof is grounded. The circuit compares the voltage magnitudes of the path voltage and the trigger voltage through a surge detection module, and only when the comparison result indicates that a surge occurs in the path between the power input end and the power output end, the power supply module is controlled to supply power to the discharge control module, so that the reference voltage source unit outputs a reference voltage, the comparison unit performs a first processing on the reference voltage and the voltage of the second end of the first resistor, and outputs a corresponding first voltage to the control end of the discharge switch to control the conduction degree of the discharge switch, and accurately clamps the voltage of the power output end to the set clamping voltage; when the comparison result indicates that no surge occurs in the path between the power input end and the power output end, the power supply module is controlled to stop supplying power to the discharge control module, so that the discharge control module stops working, thereby reducing the loss generated by the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 is a schematic diagram of the structure of a high-precision surge protection circuit in an embodiment of the present invention;

[0057] Figure 2 is a schematic diagram of the structure of a high-precision surge protection circuit in a first embodiment of the present invention;

[0058] Figure 3 is a schematic diagram of the structure of a high-precision surge protection circuit in a second embodiment of the present invention;

[0059] Figure 4 is a schematic diagram of the structure of a high-precision surge protection circuit in a third embodiment of the present invention;

[0060] Figure 5 is a schematic diagram of the structure of a high-precision surge protection circuit in a fourth embodiment of the present invention;

[0061] Figure 6 is a schematic diagram of the structure of a high-precision surge protection circuit in a fifth embodiment of the present invention;

[0062] Figure 7 is a schematic diagram of the structure of a high-precision surge protection circuit in a sixth embodiment of the present invention;

[0063] Figure 8 is a schematic diagram of the structure of a high-precision surge protection circuit in a seventh embodiment of the present invention;

[0064] Fig. 9 is a schematic diagram of the structure of a high-precision surge protection circuit in an eighth embodiment of the present invention;

[0065] Fig.10 is a schematic diagram of the structure of a high-precision surge protection circuit in a ninth embodiment of the present invention;

[0066] Fig.11 is a flow chart of a high-precision surge protection method in an embodiment of the present invention;

[0067] Fig.12 Schematic diagram of the structure of the power connection line in the embodiment of the present invention.

[0068] Description of reference numerals:

[0069] 1-High precision surge protection circuit;

[0070] Vin-power input terminal;

[0071] Vout-power output terminal;

[0072] 10- Surge detection module;

[0073] 20-power module;

[0074] 30- discharge control module;

[0075] 301-reference voltage source unit;

[0076] 302-comparison unit;

[0077] 3021-Amplifier;

[0078] 3022-first pull-down subunit;

[0079] 3023-second pull-down subunit;

[0080] Q1-first PMOS tube;

[0081] Q2- discharge switch;

[0082] R1-first resistor;

[0083] R2-second resistor;

[0084] R3-the third resistor;

[0085] R4-the fourth resistor;

[0086] Z1-first voltage zener diode;

[0087] Z2- the second voltage stabilizing diode;

[0088] Z3- the third voltage stabilizing diode;

[0089] Z4- the fourth voltage stabilizing diode;

[0090] Z5-fifth voltage zener diode;

[0091] C1 - first capacitor. DETAILED DESCRIPTION

[0092] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0093] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0094] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0095] In view of the fact that in the prior art, it is difficult for the circuit to control the output voltage of the circuit to be clamped at a set value when a surge voltage occurs, taking into account the problem that there is no impedance between the input end and the output end of the power line. In the high-precision surge protection circuit, power connection line, electronic device, charging system and high-precision surge protection method provided by the present invention, the first end of the circuit is coupled to the power input end and the power output end respectively, and the second end is grounded. The circuit compares the voltage magnitudes of the path voltage and the trigger voltage through the surge detection module, and only when the comparison result indicates that a surge occurs in the path between the power input end and the power output end, the power supply module is controlled to supply power to the discharge control module, so that the reference voltage source unit outputs the reference voltage, and the comparison unit performs a first processing on the reference voltage and the voltage of the second end of the first resistor, and outputs the corresponding first voltage to the control end of the discharge switch to control the conduction degree of the discharge switch, and accurately clamp the voltage of the power output end to the set clamping voltage; when the comparison result indicates that no surge occurs in the path between the power input end and the power output end, the power supply module is controlled to stop supplying power to the discharge control module, so that the discharge control module stops working, thereby reducing the loss generated by the circuit.

[0096] Please refer to Figure 1 , an embodiment of the present invention provides a high-precision surge protection circuit, a first end of which is respectively coupled to a power input terminal Vin and a power output terminal Vout, and a second end of which is grounded; the high-precision surge protection circuit includes a surge detection module 10, a power module 20, a discharge control module 30 and a discharge switch Q2; the discharge control module 30 includes a reference voltage source unit 301, a comparison unit 302, a first resistor R1 and a second resistor R2;

[0097] The first end of the surge detection module 10, the first end of the first resistor R1 and the first end of the discharge switch Q2 are respectively coupled to the power input terminal Vin and the power output terminal Vout; the second end of the surge detection module 10 is coupled to the input terminal of the power module 20, and the third end thereof is grounded; the output end of the power module 20 is respectively coupled to the input end of the reference voltage source unit 301 and the first end of the comparison unit 302; the output end of the reference voltage source unit 301 is coupled to the first input end of the comparison unit 302, the second end of the first resistor R1 is respectively coupled to the second input end of the comparison unit 302 and the first end of the second resistor R2, and the second end of the second resistor R2 is grounded; the output end of the comparison unit 302 is coupled to the control end of the discharge switch Q2, and the second end of the discharge switch Q2 is grounded, wherein:

[0098] The surge detection module 10 is used to compare the voltage of the path voltage and the trigger voltage, and only when the comparison result indicates that a surge occurs in the path between the power input terminal Vin and the power output terminal Vout, control the power module 20 to supply power to the discharge control module 30; otherwise, control the power module 20 to stop supplying power to the discharge control module 30;

[0099] The reference voltage source unit 301 is configured to: output a reference voltage only when the power module 20 supplies power to the discharge control module 30; otherwise, output a power ground voltage;

[0100] The comparison unit 302 is configured to:

[0101] When the power module 20 supplies power to the discharge control module 30, the reference voltage and the voltage at the second end of the first resistor R1 are first processed, and the corresponding first voltage is output to the control end of the discharge switch Q2 to control the conduction degree of the discharge switch Q2, and the voltage at the power output end Vout is clamped to the clamping voltage; the first processing at least includes subtraction amplification processing;

[0102] When the power module 20 stops supplying power to the discharge control module 30 , the power ground voltage is output to the control end of the discharge switch Q2 to control the discharge switch Q2 to be turned off.

[0103] The path voltage is the voltage on the path from the power input terminal Vin to the power output terminal Vout.

[0104] Since the first end of the high-precision surge protection circuit provided by the present invention is respectively coupled to the power input terminal Vin and the power output terminal Vout, there is no impedance between the input terminal and the output terminal of the power line, which ensures that the circuit does not generate additional heat during normal operation and does not cause stability damage to the circuit itself; at the same time, since the present invention adopts a reference voltage source module, the reference voltage value will not change when the external environment temperature fluctuates, thereby ensuring the stability of the clamping voltage value, and the present invention can also use the reference voltage value to set the voltage value of the clamping voltage;

[0105] In one implementation, the voltage value of the clamping voltage may be configured as:

[0106]

[0107] Among them, V CLAMP is the clamping voltage value, R1 is the resistance value of the first resistor R1, R2 is the resistance value of the second resistor R2, V IN+ is the voltage value of the reference voltage.

[0108] In a specific implementation, please refer to Figure 2 , the comparison unit 302 includes an amplifier 3021, a first PMOS tube Q1, a third resistor R3 and a first pull-down sub-unit 3022;

[0109] The power supply end of the amplifier 3021 is coupled to the output end of the power module 20, the non-inverting input end thereof is coupled to the output end of the reference voltage source unit 301, the inverting input end thereof is coupled to the second end of the first resistor R1, the output end thereof is coupled to the control end of the first PMOS tube Q1, the source of the first PMOS tube Q1 is coupled to the output end of the power module 20, the drain thereof is respectively coupled to the first end of the first pull-down subunit 3022 and the first end of the third resistor R3, and the second end of the first pull-down subunit 3022 is grounded; the second end of the third resistor R3 is coupled to the control end of the discharge switch Q2 to output the corresponding first voltage or the power ground voltage; wherein:

[0110] The amplifier 3021 is configured as:

[0111] When the power supply module 20 supplies power to the discharge control module 30, the voltage value received at the in-phase input terminal thereof is compared with the voltage value received at the in-phase input terminal thereof, and if the voltage value received at the in-phase input terminal thereof is greater than the voltage value received at the in-phase input terminal thereof, the power supply voltage of the power supply module 20 is output;

[0112] If the voltage value received at its non-inverting input terminal is less than or equal to the voltage value received at its inverting input terminal, the reference voltage and the voltage at the second end of the first resistor R1 are subtracted and amplified, and a corresponding second voltage value is output to the control end of the first PMOS tube Q1 to control the conduction degree of the first PMOS tube Q1 and clamp the voltage at the power output end to the clamping voltage.

[0113] The power supply voltage of the power module 20 may be understood as the power supply voltage provided by the power module 20 to the amplifier 3021 .

[0114] In a specific implementation, the discharge switch provided by the present invention may be an NMOS tube. Of course, the present invention is not limited to this, as long as the on-off of the discharge switch Q2 is controlled by the voltage of the second end of the third resistor R3, it is within the protection scope of the present invention.

[0115] The working principle of the amplifier 3021 provided by the present invention is now described.

[0116] Specifically, for the operational amplifier, if the voltage value received by the non-inverting input terminal V+ is greater than the voltage value received by the inverting input terminal V-, the output is the power supply voltage of the power module, which is insufficient to turn on the first PMOS tube Q1, and the gate of the discharge switch Q2 will be pulled to 0V by the pull-down unit (the first pull-down subunit 3022, or the first pull-down subunit 3022 and the second pull-down subunit 3023 described below), and naturally the voltage Vin of the power input terminal will not be discharged;

[0117] If the voltage value received by its non-inverting input terminal V+ is less than the voltage value received by its inverting input terminal V-, the operational amplifier is equivalent to working in the comparator mode, and the operational amplifier will output 0V, so that the first PMOS tube Q1 is fully turned on, and then the discharge switch Q2 is turned on, pulling down the voltage Vin of the power input terminal, so that the path voltage between the power input terminal and the power output terminal decreases until V- and V+ are equal;

[0118] When the voltage value received by the inverting input terminal V- is equal to the voltage value received by the non-inverting input terminal V+, the operational amplifier will operate in normal mode, so that the voltage Vin at the power input terminal is at the set value.

[0119] In a specific implementation, please refer to Figure 3 , the first pull-down subunit 3022 includes a resistor.

[0120] In this case, when the power module 20 supplies power to the discharge control module 30 , the first pull-down subunit 3022 and the PMOS transistor Q1 work together to control the gate voltage of the NMOS transistor Q2 .

[0121] When the power module 20 stops supplying power to the discharge control module 30, Q1 is turned off, and the gate voltage of the NMOS tube Q2 is pulled to the lowest potential through the first pull-down subunit 3022. At this time, Q2 is turned off and will not draw current from the power input terminal Vin, thereby ensuring the normal operation of the subsequent circuit.

[0122] Of course, the present invention does not limit the specific implementation of the first pull-down subunit. In another specific implementation, please refer to Figure 4 , the first pull-down subunit 3022 includes a pull-down current source.

[0123] exist Figure 4 In the example, the pull-down current source is composed of a third NMOS tube MN3 and a fourth NMOS tube MN4, the drain of the third NMOS tube MN3 receives a reference current, the drain of the third NMOS tube MN3 is also coupled to its gate, the source of the third NMOS tube MN3 is grounded, the gate of the third NMOS tube MN3 is coupled to the gate of the fourth NMOS tube MN4, the drain of the fourth NMOS tube MN4 is coupled to the drain of the first PMOS tube Q1, and the source of the fourth NMOS tube MN4 is grounded.

[0124] certainly, Figure 4 The structure of the pull-down current source in the figure is only an example, and those skilled in the art can select a suitable circuit as needed.

[0125] In this case, please continue to refer to Figure 4 , the comparison unit also needs to include a second pull-down subunit 3023;

[0126] A first end of the second pull-down subunit 3023 is coupled to a second end of the third resistor R3 , and a second end of the second pull-down subunit 3023 is grounded.

[0127] The working state of the second pull-down subunit is controlled according to the voltage change in the power module 20 .

[0128] In one embodiment, please continue to refer to Figure 5 , the power module includes a second PMOS tube MP2, a first capacitor C1, a fifth resistor R5, a third PMOS tube MP3, a first NMOS tube MN1, a second NMOS tube MN2, a fourth PMOS tube MP4, a sixth resistor R6 and a first diode D1;

[0129] The source and gate of the second PMOS tube MP2 are coupled to the second end of the surge detection module 10, the drain of the second PMOS tube MP2 is respectively coupled to the first end of the first capacitor C1, the first end of the fifth resistor R5, the gate of the third PMOS tube MP3 and the gate of the first NMOS tube MN1, the second end of the first capacitor C1 and the second end of the fifth resistor R5 are grounded, the source of the third PMOS tube MP3 is coupled to the gate of the second PMOS tube MP2, and the drain of the third PMOS tube MP3 is respectively coupled to the first NMOS The drain of the S tube MN1 and the gate of the fourth PMOS tube MP4, the source of the first NMOS tube MN1 is grounded, the source of the fourth PMOS tube MP4 is coupled to the source of the second NMOS tube MN2, the drain of the second NMOS tube MN2 is coupled to the first end of the surge detection module, and its gate is coupled to the gate of the second PMOS tube MP2, the drain of the fourth PMOS tube MP4 is respectively coupled to the first end of the sixth resistor R6 and the cathode of the first diode D1, and the second end of the sixth resistor R6 and the anode of the first diode D1 are both grounded.

[0130] exist Figure 5 In the example, the voltage A at the anode of the first diode D1 is VDD It can be understood as the voltage provided by the power module to the subsequent circuit.

[0131] Furthermore, in a specific implementation, please refer to Figure 6 , the second pull-down submodule includes a seventh resistor R7, a third NMOS transistor MN3 and a fourth NMOS transistor MN4;

[0132] The first end of the seventh resistor R7 is coupled to the anode of the first diode D1, and the second end thereof is respectively coupled to the drain of the third NMOS transistor MN3 and the gate of the fourth NMOS transistor MN4. The gate of the third NMOS transistor MN3 is coupled to the first end of the fifth resistor R5, and the source thereof is grounded. The drain of the fourth NMOS transistor MN4 is coupled to the second end ( Figure 6 ), whose source is grounded.

[0133] In this case, when the power module 20 supplies power to the discharge control module 30, the first pull-down subunit 3022 and the PMOS tube Q1 work together to control the gate voltage of the NMOS tube Q2;

[0134] When the power module 20 stops supplying power to the discharge control module 30, Q1 is turned off, and the gate voltage of the NMOS tube Q2 is pulled to the lowest potential through the second pull-down subunit 3023. At this time, Q2 is turned off and will not draw current from the power input terminal Vin, thereby ensuring the normal operation of the subsequent circuit.

[0135] Now combined Figure 7 , the working process of the high-precision surge protection circuit is described:

[0136] In actual implementation, the surge detection module includes at least one voltage stabilizing diode.

[0137] exist Figure 7 In the example, the surge detection module 10 includes a first Zener diode Z1, a second Zener diode Z2, a third Zener diode Z3, a fourth resistor R4 and a fourth Zener diode Z4 connected in series in sequence;

[0138] The first end of the first Zener diode Z1 is coupled to the power input terminal Vin, the fourth Zener diode Z4 is grounded, and the first end and the second end of the fourth resistor R4 are respectively coupled to the first input terminal and the second input terminal of the power module 20 to output the comparison result to the power module 20.

[0139] in this case, Figure 5 The source and the gate of the second PMOS transistor MP2 in the power module are respectively coupled to the first end and the second end of the fourth resistor R4.

[0140] In actual operation, the surge voltage generally reaches 50-300V. In this case, if a surge occurs at the power input terminal Vin, the voltage value of the path voltage will be higher, which will trigger the surge detection module 10 to work and avoid subsequent circuit damage; wherein, the voltage value of the path voltage at this time is the sum of the voltage value of the power supply voltage and the voltage value of the surge voltage, and the power supply voltage is the normal working voltage provided by the power input terminal Vin. In an embodiment of the present invention, the trigger voltage is the sum of the Zener voltage of the first Zener diode Z1, the Zener voltage of the second Zener diode Z2, and the Zener voltage of the third Zener diode Z3. In an example, the Zener voltages of the first Zener diode Z1, the second Zener diode Z2, the third Zener diode Z3, and the fourth Zener diode Z4 are all 6V; in actual operation, the clamping voltage of the circuit can be 25-27V.

[0141] In this case, if current flows inside the surge detection module 10, and the voltage value received by the non-inverting input terminal of the amplifier 3021 is less than or equal to the voltage value received by the inverting input terminal thereof, the amplifier 3021 controls the conduction degree of the discharge switch Q2 by controlling the conduction degree of the first PMOS tube Q1. Figure 7 In the example shown, the conduction degree of the first PMOS tube Q1 controls the gate voltage of the discharge switch Q2 to meet the discharge requirement.

[0142] Of course, the present invention does not limit the specific number of voltage-stabilizing diodes and the magnitude of their Zener voltages, which can be set according to the voltage value of the power supply voltage and / or the voltage that the power module 20 can withstand in actual work;

[0143] For an example, please refer to Figure 8 , if the circuit is designed such that the Zener voltage of the voltage regulator diode is 6V, the voltage value of the supply voltage is less than 5V when the circuit is working normally, and the clamping voltage is 6-8V, then the surge detection module 10 can be designed to include a fourth resistor R4 and a fourth voltage regulator diode Z4 connected in series in sequence;

[0144] In another example, see Fig. 9 If the circuit is designed so that the Zener voltage of the Zener diodes is 6V, the voltage value of the supply voltage is less than 30V when the circuit is working normally, and the clamping voltage is 33-36V, then the surge detection module 10 can be designed to include a first Zener diode Z1, a second Zener diode Z2, a third Zener diode Z3, a fourth Zener diode Z4, a fourth resistor R4 and a fifth Zener diode Z5 which are connected in series in sequence.

[0145] In the above example, the trigger voltage needs to be less than or equal to the clamping voltage, so as to ensure that there is a voltage drop across the fourth resistor R4.

[0146] In other implementations, the trigger voltage may also be designed to be greater than the clamp voltage. In this case, please refer to Fig.10 The power module 20 includes a second capacitor C2; the second capacitor C2 is connected in parallel with the fourth resistor R4. The voltage across the fourth resistor R4 charges the second capacitor C2, and the second capacitor C2 is used to supply power to the discharge control module 30.

[0147] In this case, the surge detection module 10 may be designed to include a fourth resistor R4 and a fourth voltage stabilizing diode Z4 (eg, Figure 8 ); a plurality of voltage stabilizing diodes (for example Fig. 9The surge detection module 10 shown;

[0148] In one example, if the circuit is designed so that the Zener voltage of the voltage-stabilizing diode is 6V, the voltage value of the supply voltage is less than 24V when the circuit is working normally, the trigger voltage is 30V, and the clamping voltage is 25-27V. Please refer to Fig.10 , the surge detection module 10 can be designed to include a first Zener diode Z1, a second Zener diode Z2, a third Zener diode Z3, a fourth Zener diode Z4, a fourth resistor R4 and a fifth Zener diode Z5 which are connected in series in sequence.

[0149] Of course, when the power module 20 includes the second capacitor C2, the trigger voltage may also be designed to be less than or equal to the clamping voltage.

[0150] It should be understood that the surge in the path between the power input terminal and the power output terminal mentioned in the embodiment of the present invention can be understood as the voltage of the path between the power input terminal and the power output terminal being greater than or equal to the trigger voltage.

[0151] In addition, the embodiment of the present invention also provides a high-precision surge protection method for Figure 1-Figure 10 The high-precision surge protection circuit is controlled, and the method includes:

[0152] Compare the voltages of the path voltage and the trigger voltage, and only when the comparison result indicates that a surge occurs in the path between the power input terminal Vin and the power output terminal Vout, control the power module 20 to supply power to the discharge control module 30; otherwise, control the power module 20 to stop supplying power to the discharge control module 30; wherein:

[0153] If the power module 20 supplies power to the discharge control module 30, the following steps are performed:

[0154] Controlling the reference voltage source unit 301 to output a reference voltage;

[0155] Performing a first processing on the reference voltage and the voltage at the second end of the first resistor R1, and outputting a corresponding first voltage to the control end of the discharge switch Q2, so as to control the conduction degree of the discharge switch Q2, and clamping the voltage at the power output end Vout to the clamping voltage; the first processing at least includes a subtraction amplification processing;

[0156] If the power module 20 stops supplying power to the discharge control module 30, the following steps are performed:

[0157] Controlling the reference voltage source unit 301 to output a power supply ground voltage;

[0158] The power ground voltage is output to the control end of the discharge switch Q2 to control the discharge switch Q2 to be turned off.

[0159] As a specific implementation, please refer to Fig.11 In actual use, the embodiments of the present invention provide Figure 1 The high-precision surge protection circuit shown in the figure is controlled by the following steps:

[0160] S41: Power on;

[0161] Specifically, there is a voltage signal in the path between the power input terminal Vin and the power output terminal Vout, and the high-precision surge protection circuit works normally;

[0162] Of course, if there is no voltage signal in the path between the power input terminal Vin and the power output terminal Vout, which is equivalent to the path voltage being less than the trigger voltage, the power module 20 stops supplying power to the discharge control module 30 .

[0163] S42: comparing the voltage of the path voltage and the trigger voltage, and when the comparison result indicates that a surge occurs in the path between the power input terminal Vin and the power output terminal Vout, proceed to S43; otherwise, proceed to S46;

[0164] Specifically, the surge detection module 10 compares the voltage of the path voltage and the trigger voltage, and only when the comparison result indicates that a surge occurs in the path between the power input terminal Vin and the power output terminal Vout, the process proceeds to S43, otherwise, the process proceeds to S46;

[0165] S43: Control the power module 20 to supply power to the discharge control module 30;

[0166] S44: controlling the reference voltage source unit 301 to output a reference voltage;

[0167] S45: performing a first process on the reference voltage and the voltage at the second end of the first resistor R1, and outputting a corresponding first voltage to the control end of the discharge switch Q2 to control the conduction degree of the discharge switch Q2, and clamping the voltage at the power output end Vout to the clamping voltage; and returning to S42;

[0168] Specifically, the first processing at least includes subtraction and amplification processing;

[0169] S46: Control the power module 20 to stop supplying power to the discharge control module 30;

[0170] S47: Control the reference voltage source unit 301 to output a power ground voltage;

[0171] S48: output the power ground voltage to the control end of the discharge switch Q2 to control the discharge switch Q2 to be turned off, and return to S42.

[0172] In a specific implementation manner, in Figures 1 to 9 When the high-precision surge protection circuit shown is controlled, the trigger voltage needs to be greater than the clamping voltage;

[0173] For Fig.10 When the high-precision surge protection circuit shown is controlled, the trigger voltage may be less than or equal to the clamping voltage, or may be greater than the clamping voltage.

[0174] In addition, please refer to Fig.12 An embodiment of the present invention further provides a power connection line to provide a connection between a power supply device and a device for charging, including a voltage bus and a high-precision surge protection circuit 1 connected in parallel to the voltage bus; of course, the present invention does not limit the interface type of the connection line, and it can also be other interfaces, such as Type A, etc.

[0175] In addition, an embodiment of the present invention further provides an electronic device, comprising the above-mentioned high-precision surge protection circuit. As an example, the above-mentioned high-precision surge protection circuit can be used as a surge protection circuit for a voltage input terminal of a chip.

[0176] In addition, an embodiment of the present invention further provides a charging system, including the above-mentioned high-precision surge protection circuit. As an example, it can be a fast charging system, etc., and of course it can also be other systems that need to be charged.

[0177] In summary, the embodiment of the present invention compares the voltage magnitudes of the path voltage and the trigger voltage through the surge detection module, and only when the comparison result indicates that a surge occurs in the path between the power input terminal and the power output terminal, controls the power supply module to supply power to the discharge control module, so that the reference voltage source unit outputs a reference voltage, and the comparison unit performs a first processing on the reference voltage and the voltage of the second end of the first resistor, and outputs a corresponding first voltage to the control end of the discharge switch to control the conduction degree of the discharge switch, and accurately clamps the voltage of the power output terminal to the set clamping voltage; when the comparison result indicates that no surge occurs in the path between the power input terminal and the power output terminal, controls the power supply module to stop supplying power to the discharge control module, so that the discharge control module stops working, thereby reducing the loss generated by the circuit.

[0178] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision surge protection circuit, characterized in that: Its first end is coupled to the power input end and the power output end respectively, and its second end is grounded; the high-precision surge protection circuit includes a surge detection module, a power module, a discharge control module and a discharge switch; the discharge control module includes a reference voltage source unit, a comparison unit, a first resistor and a second resistor; The first end of the surge detection module, the first end of the first resistor, and the first end of the discharge switch are coupled to the power input end and the power output end respectively; The second end of the surge detection module is coupled to the input end of the power module, and the third end thereof is grounded; the output end of the power module is respectively coupled to the input end of the reference voltage source unit and the first end of the comparison unit; The output end of the reference voltage source unit is coupled to the first input end of the comparison unit, the second end of the first resistor is coupled to the second input end of the comparison unit and the first end of the second resistor respectively, and the second end of the second resistor is grounded; the output end of the comparison unit is coupled to the control end of the discharge switch, and the second end of the discharge switch is grounded, wherein: The surge detection module is used to compare the voltage of the path voltage and the trigger voltage, and only when the comparison result indicates that a surge occurs in the path between the power input end and the power output end, control the power module to supply power to the discharge control module; otherwise, control the power module to stop supplying power to the discharge control module; The reference voltage source unit is configured to: output a reference voltage only when the power module supplies power to the discharge control module; otherwise, output a power ground voltage; The comparison unit is configured as follows: When the power supply module supplies power to the discharge control module, the reference voltage and the voltage at the second end of the first resistor are first processed, and the corresponding first voltage is output to the control end of the discharge switch to control the conduction degree of the discharge switch and clamp the voltage at the power output end to the clamping voltage; the first processing at least includes subtraction amplification processing; When the power module stops supplying power to the discharge control module, the power ground voltage is output to the control end of the discharge switch to control the discharge switch to be turned off.

2. The high-precision surge protection circuit according to claim 1, characterized in that: The voltage value of the clamp voltage is configured as: Among them, V CLAMP is the clamping voltage value, R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, V IN+ is the voltage value of the reference voltage.

3. The high-precision surge protection circuit according to claim 2, characterized in that: The comparison unit includes an amplifier, a first PMOS tube, a third resistor and a first pull-down sub-unit; The power supply end of the amplifier is coupled to the output end of the power module, the non-inverting input end thereof is coupled to the output end of the reference voltage source unit, the inverting input end thereof is coupled to the second end of the first resistor, the output end thereof is coupled to the control end of the first PMOS tube, the source of the first PMOS tube is coupled to the output end of the power module, the drain thereof is respectively coupled to the first end of the first pull-down sub-unit and the first end of the third resistor, the second end of the first pull-down sub-unit is grounded; the second end of the third resistor is coupled to the control end of the discharge switch to output the corresponding first voltage or the power ground voltage; wherein: The amplifier is configured as: When the power supply module supplies power to the discharge control module, the voltage value received by the non-inverting input terminal thereof is compared with the voltage value received by the inverting input terminal thereof, and if the voltage value received by the non-inverting input terminal thereof is greater than the voltage value received by the inverting input terminal thereof, the power supply voltage of the power supply module is output; If the voltage value received at its non-inverting input terminal is less than or equal to the voltage value received at its inverting input terminal, the reference voltage and the voltage at the second end of the first resistor are subtracted and amplified, and a corresponding second voltage value is output to the control end of the first PMOS tube to control the conduction degree of the first PMOS tube and clamp the voltage at the power output end to the clamping voltage.

4. The high-precision surge protection circuit according to claim 3, characterized in that: The discharge switch is an NMOS tube.

5. The high-precision surge protection circuit according to claim 3, characterized in that: The first pull-down subunit includes a resistor.

6. The high-precision surge protection circuit according to claim 3, characterized in that: The power module includes a second PMOS transistor, a first capacitor, a fifth resistor, a third PMOS transistor, a first NMOS transistor, a second NMOS transistor, a fourth PMOS transistor, a sixth resistor and a first diode; The source and gate of the second PMOS tube are both coupled to the second end of the surge detection module, the drain of the second PMOS tube is respectively coupled to the first end of the first capacitor, the first end of the fifth resistor, the gate of the third PMOS tube and the gate of the first NMOS tube, the second end of the first capacitor and the second end of the fifth resistor are both grounded, the source of the third PMOS tube is coupled to the gate of the second PMOS tube, the drain of the third PMOS tube is respectively coupled to the drain of the first NMOS tube and the gate of the fourth PMOS tube, the source of the first NMOS tube is grounded, the source of the fourth PMOS tube is coupled to the source of the second NMOS tube, the drain of the second NMOS tube is coupled to the first end of the surge detection module, and its gate is coupled to the gate of the second PMOS tube, the drain of the fourth PMOS tube is respectively coupled to the first end of the sixth resistor and the negative electrode of the first diode, and the second end of the sixth resistor and the positive electrode of the first diode are both grounded.

7. The high-precision surge protection circuit according to claim 6, characterized in that: The first pull-down subunit includes a pull-down current source.

8. The high-precision surge protection circuit according to claim 7, characterized in that: The comparison unit further includes a second pull-down subunit; A first end of the second pull-down subunit is coupled to a second end of the third resistor, and a second end of the second pull-down subunit is grounded.

9. The high-precision surge protection circuit according to claim 8, characterized in that: The second pull-down submodule includes a seventh resistor, a third NMOS transistor and a fourth NMOS transistor; The first end of the seventh resistor is coupled to the anode of the first diode, and the second end thereof is respectively coupled to the drain of the third NMOS tube and the gate of the fourth NMOS tube. The gate of the third NMOS tube is coupled to the first end of the fifth resistor, and the source thereof is grounded. The drain of the fourth NMOS tube is coupled to the second end of the third resistor, and the source thereof is grounded.

10. The high-precision surge protection circuit according to claim 1, characterized in that: The surge detection module comprises a first voltage stabilizing diode, a second voltage stabilizing diode, a third voltage stabilizing diode, a fourth resistor and a fourth voltage stabilizing diode which are connected in series in sequence; The first end of the first Zener diode is coupled to the power input terminal, the fourth Zener diode is grounded, and the first end and the second end of the fourth resistor are respectively coupled to the first input terminal and the second input terminal of the power module to output the comparison result to the power module.

11. The high-precision surge protection circuit according to claim 10, characterized in that: The trigger voltage is the sum of the Zener voltage of the first Zener diode, the Zener voltage of the second Zener diode, the Zener voltage of the third Zener diode, and the Zener voltage of the fourth Zener diode.

12. The high-precision surge protection circuit according to claim 1, characterized in that: The surge detection module includes at least one voltage stabilizing diode.

13. The high-precision surge protection circuit according to claim 12, characterized in that: The trigger voltage is greater than the clamp voltage.

14. The high-precision surge protection circuit according to claim 12, characterized in that: The trigger voltage is less than or equal to the clamping voltage.

15. The high-precision surge protection circuit according to claim 14, characterized in that: The power module includes a second capacitor; the second capacitor is connected in parallel with the fourth resistor.

16. A power connection line, providing a connection between a power supply device and a device for charging, characterized in that: The invention comprises a voltage bus and a high-precision surge protection circuit as claimed in any one of claims 1 to 15 connected in parallel to the voltage bus.

17. An electronic device, characterized in that: Comprising a high-precision surge protection circuit as described in any one of claims 1-15.

18. A charging system, characterized in that: The invention comprises a power supply device and the electronic device according to claim 17.

19. A high-precision surge protection method, characterized in that: Used to control the high-precision surge protection circuit according to any one of claims 1 to 15, the method comprising: Compare the voltage magnitudes of the path voltage and the trigger voltage, and only when the comparison result indicates that a surge occurs in the path between the power input terminal and the power output terminal, control the power module to supply power to the discharge control module; otherwise, control the power module to stop supplying power to the discharge control module; wherein: If the power module supplies power to the discharge control module, the following steps are performed: Controlling the reference voltage source unit to output a reference voltage; Performing a first processing on the reference voltage and the voltage at the second end of the first resistor, and outputting a corresponding first voltage to the control end of the discharge switch to control the conduction degree of the discharge switch and clamp the voltage at the power output end to the clamping voltage; the first processing at least includes a subtraction amplification processing; If the power module stops supplying power to the discharge control module, the following steps are performed: Controlling the reference voltage source unit to output a power ground voltage; The power ground voltage is output to the control end of the discharge switch to control the discharge switch to be turned off.

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