Power adapter and control circuit, standby detection circuit and method thereof

Abstract

The present disclosure provides a power adapter and a control circuit, a standby detection circuit and a method thereof. The output end of the power adapter is provided with an interface unit, the interface unit is connected to a device to be charged through a pluggable charging cable, and the standby detection method comprises: switching the working state of the power adapter according to the connection state of the charging cable and the device to be charged; and controlling to reduce the average current of a first detection circuit in a first standby state, wherein the first detection circuit is used to detect whether the interface unit is inserted or removed from the charging cable, and the interface unit is inserted into the charging cable and not connected to the device to be charged in the first standby state. By reducing the average current flowing through the pull-down resistor of the charging cable, the standby power consumption in the first standby state is reduced, and the connection state of the charging cable can be effectively detected.

Description

Technical Field

[0001] This disclosure relates to the field of power supply technology, and in particular to a power adapter and its control circuit, standby detection circuit and method. Background Technology

[0002] As a key component connecting the power grid and electronic equipment, the power adapter converts AC mains power into a stable DC power supply required by the electronic equipment to ensure its normal operation.

[0003] In practical use, power adapters remain powered even in standby mode. During this time, the internal circuitry of the power adapter (such as the control chip and auxiliary power supply) continues to consume power, resulting in standby power consumption. Existing power adapters generally have high standby power consumption, typically exceeding 75mW. This not only wastes a significant amount of energy, contradicting current environmental trends of energy conservation and emission reduction, but also causes the power adapter to heat up slightly due to continuous power consumption, posing potential safety hazards and shortening its lifespan.

[0004] Therefore, reducing the standby power consumption of power adapters has become an important research and development direction for the industry to improve product energy efficiency and respond to green and environmental protection requirements. Summary of the Invention

[0005] In view of the above problems, the purpose of this disclosure is to provide a power adapter and its control circuit, standby detection circuit and method to achieve zero power consumption (less than 5mW) in the standby state of the power adapter.

[0006] According to a first aspect of this disclosure, a standby detection method for a power adapter is provided, wherein the output end of the power adapter is provided with an interface unit, and the interface unit is connected to a device to be charged via a pluggable charging cable, comprising: switching the operating state of the power adapter according to the connection status of the charging cable and the device to be charged; and controlling the reduction of the average current of a first detection circuit in a first standby state, wherein the first detection circuit is used to detect whether the interface unit is inserted into or unplugged from the charging cable, and in the first standby state the interface unit is inserted into the charging cable but not connected to the device to be charged.

[0007] Optionally, controlling the reduction of the average current of the first detection circuit in the first standby state includes: controlling the first detection circuit to continue operating in the first standby state, and the operating current being less than a preset current.

[0008] Optionally, controlling the reduction of the average current of the first detection circuit in the first standby state includes: controlling the first detection circuit to operate periodically in the first standby state, and the operating current is less than or equal to a preset current.

[0009] Optionally, the preset current is the operating current of the first detection circuit when the power adapter is in normal working condition, in which the interface unit is connected to the device to be charged by inserting the charging cable.

[0010] Optionally, it further includes: controlling a second detection circuit to continue operating in the first standby state, the second detection circuit being used to detect whether the interface unit is inserted into or removed from the device to be charged.

[0011] Optionally, it further includes: controlling a second detection circuit to operate periodically in the first standby state, the second detection circuit being used to detect the insertion or removal of the interface unit from the device to be charged, wherein in each cycle, the conduction duration of the second detection circuit is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit is greater than or equal to a preset duty cycle.

[0012] Optionally, it further includes: controlling the first detection circuit and the second detection circuit to continue working in the second standby state, the second detection circuit being used to detect whether the interface unit is inserted into or unplugged from the device to be charged, and in the second standby state, the interface unit unplugs the charging cable and is not connected to the device to be charged.

[0013] Optionally, it further includes: controlling the power switch to turn off in a first standby state and a second standby state, wherein the power switch is connected between the output terminal and the interface unit.

[0014] Optionally, it further includes: detecting the pull-down resistor of the first detection circuit when the charging cable is connected or disconnected, to determine whether the interface unit is connected or disconnected from the charging cable; and detecting the pull-down resistor of the second detection circuit when the device to be charged is connected or disconnected, to determine whether the interface unit is connected or disconnected from the device to be charged.

[0015] Optionally, switching the operating state of the power adapter according to the connection status of the charging cable and the device to be charged includes: controlling the power adapter to enter a second standby state when the first detection circuit detects that the charging cable has been removed; controlling the power adapter to enter a normal state when the second detection circuit detects that the device to be charged has been connected; and controlling the power adapter to enter a first standby state when the first detection circuit detects that the charging cable has been inserted and the second detection circuit detects that the device to be charged has not been connected.

[0016] According to a second aspect of this disclosure, a standby detection circuit for a power adapter is provided. The power adapter has an interface unit at its output terminal, and the interface unit is connected to a device to be charged via a pluggable charging cable. The circuit includes: a first detection circuit connected to the output terminal for being powered and connected to the interface unit to detect whether the interface unit is inserted into or removed from the charging cable; and a state machine that switches the operating state of the power adapter according to the connection status of the charging cable and the device to be charged, and controls the reduction of the average current of the first detection circuit in a first standby state, wherein the interface unit is inserted into the charging cable but not connected to the device to be charged in the first standby state.

[0017] Optionally, the state machine controls the first detection circuit to be continuously turned on in the first standby state, and the operating current is less than a preset current; or the state machine controls the first detection circuit to be turned on periodically in the first standby state, and the operating current is less than or equal to a preset current. The preset current is the operating current of the first detection circuit when the power adapter is working normally, and in the normal state, the interface unit is connected to the device to be charged by inserting the charging cable.

[0018] Optionally, it further includes: a second detection circuit, connected to the output terminal to be powered, and connected to the interface unit to detect whether the interface unit is inserted into or removed from the device to be charged, wherein, in the first standby state, the state machine controls the second detection circuit to work continuously, or the state machine controls the second detection circuit to work periodically, wherein in each cycle, the conduction duration of the second detection circuit is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit is greater than or equal to a preset duty cycle.

[0019] Optionally, the interface unit includes two detection interfaces, each of which is connected to a detection circuit between itself and the output terminal of the power adapter. One detection interface corresponds to a pull-down resistor in the charging cable, and the other detection interface corresponds to a pull-down resistor in the device to be charged. The detection circuit connected to the detection interface corresponding to the pull-down resistor in the charging cable is a first detection circuit, and the detection circuit connected to the detection interface corresponding to the pull-down resistor in the device to be charged is a second detection circuit. The second detection circuit is used to detect whether the interface unit is inserted into or removed from the device to be charged.

[0020] Optionally, each detection circuit includes a detection switch and a detection resistor connected in series. In the first standby state, the first detection circuit is connected to a pull-down resistor in the charging cable via a detection interface.

[0021] According to a third aspect of this disclosure, a control circuit for a power adapter is provided, including the standby detection circuit described above.

[0022] According to a fourth aspect of this disclosure, a power adapter is provided, comprising: an output terminal; a power switch; a voltage converter for converting an AC input voltage into a DC output voltage and outputting it via the output terminal; an interface unit connected to the output terminal via the power switch; and a control circuit as described above.

[0023] The power adapter and its control circuit, standby detection circuit and method provided in this disclosure can reduce the average current flowing through the pull-down resistor of the charging cable by controlling and reducing the average current of the first detection circuit in the first standby state, thereby reducing the standby power consumption in the first standby state.

[0024] This disclosure also includes maintaining the second detection circuit on in the first standby state. Alternatively, it may periodically activate the second detection circuit, with the activation duration of the second detection circuit being greater than or equal to a preset duration and the duty cycle of the second detection circuit being greater than or equal to a preset duty cycle within each cycle. This ensures that the connection status of the charging cable and the device to be charged can be effectively detected.

[0025] The power adapter and its control circuit, standby detection circuit and method disclosed herein reduce standby power consumption in the first standby state by controlling the first detection circuit to operate continuously in a first standby state, with the operating current being less than a preset current; or by controlling the first detection circuit to operate periodically, with the operating current being less than or equal to a preset current.

[0026] Furthermore, in the second standby state, this disclosure controls the second detection circuit to remain on and controls the first detection circuit to remain on, so as to ensure that the connection status of the charging cable and the device to be charged can be effectively detected. Attached Figure Description

[0027] The above and other objects, features, and advantages of this disclosure will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0028] Figure 1 A schematic diagram of the electrical connections of the power adapter in standby mode is shown.

[0029] Figure 2 A schematic diagram of a power adapter provided in an embodiment of this disclosure in a second standby state is shown;

[0030] Figure 3 This diagram illustrates the electrical connections of the power adapter provided in an embodiment of the present disclosure in a first standby state.

[0031] Figure 4 This diagram illustrates the electrical connections of the power adapter provided in this embodiment under normal conditions.

[0032] Figure 5 This diagram illustrates the state transitions of a state machine in a power adapter according to an embodiment of the present disclosure.

[0033] Figure 6 This diagram illustrates a waveform of a power adapter provided in an embodiment of the present disclosure in a first standby state.

[0034] Figure 7 This diagram illustrates another waveform of the power adapter provided in an embodiment of the present disclosure in a first standby state;

[0035] Figure 8 This diagram illustrates another waveform of the power adapter provided in an embodiment of the present disclosure in a first standby state;

[0036] Figure 9 This diagram illustrates a standby detection method for a power adapter provided in an embodiment of the present disclosure. Detailed Implementation

[0037] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0038] Figure 1 This diagram shows the electrical connections of the power adapter in standby mode.

[0039] A power adapter is a standalone hardware interface device that connects the power grid to electronic devices, converting AC mains power into a stable DC power supply required by the devices. To save energy, the industry is dedicated to developing power adapters with zero standby power consumption (<5mW). This will be explained in detail below.

[0040] like Figure 1 The diagram illustrates two standby states of the power adapter. State a refers to the first standby state: the power adapter 100 is connected to the power grid and receives AC input voltage ACinput; the power adapter 100 is only connected to the charging cable and is not connected to the device 300 to be charged. State b refers to the second standby state: the power adapter 100 is connected to the power grid and receives AC input voltage ACinput; the power adapter 100 is not connected to the charging cable and is not connected to the device 300 to be charged.

[0041] In existing technologies, the standby power consumption of a power adapter is tested based on a second standby state. However, in practical applications, more often the power device is unplugged, but the charging cable remains plugged into the power adapter. In this scenario, especially in power adapters rated at 3A or higher, the compatible charging cable typically includes a pull-down resistor. Consequently, during the testing process, the charging cable experiences additional standby power consumption, increasing the power consumption of the power adapter in the first standby state and failing to meet the zero-power requirement.

[0042] Figure 2 A schematic diagram of a power adapter provided in an embodiment of this disclosure in a second standby state is shown. Figure 3 This diagram illustrates the electrical connections of a power adapter provided in an embodiment of the present disclosure in a first standby state. Figure 4 This diagram illustrates the electrical connections of a power adapter provided in an embodiment of the present disclosure under normal conditions. Figure 5 This diagram illustrates the state transitions of a state machine in a power adapter according to an embodiment of the present disclosure. Figure 6 This diagram illustrates a waveform of a power adapter provided in an embodiment of the present disclosure in a first standby state. Figure 7 This diagram illustrates another waveform of the power adapter provided in an embodiment of the present disclosure in a first standby state. Figure 8 This diagram illustrates another waveform of the power adapter provided in the embodiments of the present disclosure in the first standby state.

[0043] Combination Figure 2 , Figure 3 , Figure 4 As shown, the power adapter 100 provided in this application includes a voltage converter 110, a power switch Q1, an interface unit 120, and a control circuit 130.

[0044] The control circuit 130 includes, for example, a standby detection circuit 140 and a switch control circuit 150. In one example, the standby detection circuit 140 and the switch control circuit 150 are integrated in the same chip. In another alternative example, the standby detection circuit 140 and the switch control circuit 150 are integrated separately.

[0045] Voltage converter 110 converts the AC input voltage ACinput into a DC output voltage and outputs it via the output terminal out. Exemplarily, voltage converter 110 is, for example, a flyback converter, and its standby power consumption includes primary-side power consumption and secondary-side power consumption. The solution in this application mainly focuses on controlling the secondary-side power consumption.

[0046] The output terminal 'out' of the power adapter 100 is connected to an interface unit 120, which is connected to the device 300 to be charged via a pluggable charging cable 200. The interface unit 120 includes two detection interfaces (a first detection interface CC1 and a second detection interface CC2). Each detection interface is connected to a detection circuit via a path. Furthermore, one detection interface corresponds to a pull-down resistor Ra in the charging cable 200, and the other detection interface corresponds to a pull-down resistor Rd in the device 300 to be charged.

[0047] Further, the detection circuit connected to the detection interface corresponding to the pull-down resistor Ra in the charging cable 200 is the first detection circuit 141, and the detection circuit connected to the detection interface corresponding to the pull-down resistor Rd in the device to be charged 300 is the second detection circuit 142. For example, the first detection interface CC1 corresponds to the pull-down resistor Rd in the device to be charged 300. The second detection interface CC2 corresponds to the pull-down resistor Ra in the charging cable 200. Under normal conditions, the first detection interface CC1 is connected to the pull-down resistor Rd in the device to be charged 300 via the charging cable 200. The second detection interface CC2 is connected to the pull-down resistor Ra in the charging cable 200. In the first standby state, only the second detection interface CC2 is connected to the pull-down resistor Ra in the charging cable 200.

[0048] The interface unit 120 also receives a DC output voltage and outputs it via a detection interface. Of course, the first detection interface CC1 can also correspond to the pull-down resistor Ra in the charging cable 200, and the second detection interface CC2 can also correspond to the pull-down resistor Rd in the device to be charged 300.

[0049] The first terminal of power switch Q1 is connected to the output terminal out to receive the DC output voltage VIN. The second terminal of power switch Q1 is connected to the interface unit 120. The control terminal of power switch Q1 is connected to the switch control circuit 150. The switch control circuit 150 provides a switch control signal to power switch Q1 to control power switch Q1 to turn on or off.

[0050] Furthermore, the standby detection circuit 140 includes a first detection circuit 141, a second detection circuit 142, and a state machine 143.

[0051] The first detection circuit 141 is connected to the output terminal out to be powered, and the first detection circuit 141 is connected to the interface unit 120 to detect whether the interface unit 120 inserts or removes the charging cable 200.

[0052] The second detection circuit 142 is connected to the output terminal out to be powered, and the second detection circuit 142 is connected to the interface unit 120 to detect whether the interface unit 120 is connected to the device 300 to be charged.

[0053] The state machine 143 switches the operating state of the power adapter 100 according to the connection status of the charging cable 200 and the device 300 to be charged. The operating states include a normal state, a first standby state, and a second standby state. The normal state indicates that the interface unit of the power adapter is connected to the device to be charged by inserting the charging cable. The first standby state indicates that the interface unit of the power adapter is connected to the charging cable but not to the device to be charged. The second standby state indicates that the interface unit of the power adapter is disconnected from the charging cable and not to the device to be charged.

[0054] For example, the second detection circuit 142 includes a second detection unit, a detection switch K1 connected in series between the output terminal out and the first interface CC1, and a detection resistor Rp1. The first detection circuit 141 includes a first detection unit, a detection switch K2 connected in series between the output terminal out and the second interface CC2, and a detection resistor Rp2. A state machine 143 is connected to the control terminals of the detection switches K1 and K2 to control the operating current in the corresponding operating state. Further, the state machine 143 is also connected to the switch control circuit 150 to control the power switch Q1 to be turned on or off in the corresponding operating state.

[0055] like Figure 2 As shown, in the second standby state S0, the first interface CC1 and the second interface CC2 in the interface unit 120 of the power adapter 100 are floating. In this state, the switch control circuit 150 controls the power switch Q1 to turn off according to the state machine 143. That is, the secondary side of the voltage converter 110 is in a deep sleep state. The state machine 143 in the standby detection circuit 140 also controls the detection switches K1 and K2 to be normally turned on, so as to detect the insertion or removal of electronic cables or devices to be charged in the interface unit 120 in real time.

[0056] Since the interface unit 120 is not connected to a charging cable or a device to be charged in the second standby state, no additional standby power consumption is introduced. Furthermore, the connection status of the interface unit 120 can be detected in real time during this operating state, improving the standby detection performance of the power adapter.

[0057] like Figure 4 As shown, in normal state S2, the first interface CC1 of the interface unit 120 of the power adapter 100 is connected to the pull-down resistor Rd in the device to be charged 300 via the charging cable 200, and the second interface CC2 of the interface unit 120 of the power adapter 100 is connected to the pull-down resistor Ra in the charging cable 200. In this state, the switch control circuit 150 controls the power switch Q1 to be turned on according to the state machine 143. The state machine 143 in the standby detection circuit 140 also controls the detection switches K1 and K2 to be constantly turned on, so as to detect in real time whether the interface unit 120 inserts or removes the electronic cable or the device to be charged.

[0058] like Figure 3 As shown, in the first standby state S1, the first interface CC1 in the interface unit 120 of the power adapter 100 is connected to the charging cable 200 but not connected to the device to be charged 300, and the second interface CC2 in the interface unit 120 of the power adapter 100 is connected to the second pull-down resistor Ra in the charging cable 200.

[0059] In this state, the switch control circuit 150 controls the power switch Q1 to turn off according to the state machine 143. The control method of the state machine 143 over the first detection circuit 141 and the second detection circuit 142 will be described in detail later.

[0060] like Figure 5 As shown, the output of state machine 143 is controlled by the current state. Specifically, the second standby state S0 indicates that both the first interface CC1 and the second interface CC2 in interface unit 120 are floating. The first standby state S1 indicates that the first interface CC1 in interface unit 120 is not connected to a pull-down resistor Rd, and the second interface CC2 is connected to a pull-down resistor Ra. The normal state S2 indicates that the first interface CC1 in interface unit 120 is connected to a pull-down resistor Rd, and the second interface CC2 is connected to a pull-down resistor Ra.

[0061] When state machine 143 is in the second standby state S0, and the input indication of state machine 143 indicates that only the second interface CC2 is connected to the pull-down resistor Ra, state machine 143 switches to the first standby state S1. When state machine 143 is in the second standby state S0, and the input indication of state machine 143 indicates that the first interface CC1 is connected to the pull-down resistor Rd and the second interface CC2 is connected to the pull-down resistor Ra, state machine 143 switches to the normal state S2.

[0062] When state machine 143 is in the first standby state S1, and the input indication of state machine 143 indicates that the pull-down resistor Rd is connected to the first interface CC1, state machine 143 switches to the normal state S2. When state machine 143 is in the first standby state S1, and the input indication of state machine 143 indicates that the pull-down resistor Ra is removed from the second interface CC2, state machine 143 switches to the second standby state S0.

[0063] When state machine 143 is in normal state S2, and the input indication of state machine 143 is that the first interface CC1 removes the pull-down resistor Rd and the second interface CC2 removes the pull-down resistor Ra, state machine 143 switches to the second standby state S0. When state machine 143 is in normal state S2, and the input indication of state machine 143 is that the first interface CC1 removes the pull-down resistor Rd, state machine 143 switches to the first standby state S1.

[0064] In the first embodiment of this application, in the first standby state S1, the first detection circuit 141 continues to operate (i.e., the detection switch K2 continues to be turned on). The operating current Is1 of the first detection circuit 141 in the first standby state S1 is less than the operating current Is2 of the first detection circuit 141 in the normal state S2. This reduces the power consumption of the second pull-down resistor Ra in the charging cable 200 connected to the power adapter in the first standby state S1.

[0065] Furthermore, in the first standby state S1, the second detection circuit 142 is controlled to operate continuously. Alternatively, in the first standby state S1, the second detection circuit 142 is controlled to operate periodically, wherein in each cycle, the conduction duration of the second detection circuit 142 is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit 142 is greater than or equal to a preset duty cycle.

[0066] Furthermore, in the second standby state S0, the first detection circuit 141 and the second detection circuit 142 are controlled to continue to work.

[0067] For example, such as Figure 6 As shown, the state machine 143 switches to the first standby state S1, and the corresponding output control signal GR indicates that the control detection switch K1 and the detection switch K2 are normally turned on, and makes the operating current Is1 of the first detection circuit 141 less than the operating current Is2 of the first detection circuit 141 in the normal state.

[0068] In the second embodiment of this application, the difference from the first embodiment is that, in the first standby state S1, the first detection circuit 141 operates periodically (i.e., the detection switch K2 is periodically turned on). The operating current Is1 of the first detection circuit 141 in the first standby state S1 is less than the operating current Is2 of the first detection circuit 141 in the normal state S2. This, in turn, reduces the power consumption of the second pull-down resistor Ra in the charging cable 200 connected to the power adapter in the first standby state S1.

[0069] For example, such as Figure 7 As shown, the state machine 143 switches to the first standby state S1, corresponding to the output control signal GR indicating that the control detection switch K1 is normally on and the detection switch K2 is periodically on, and that the operating current Is1 of the first detection circuit 141 is less than the operating current Is2 of the first detection circuit 141 under normal conditions. The switching period of switch K2 is... The value is less than a first threshold, which is set according to actual needs. Further, the conduction duration of switch K2 in each switching cycle... Smaller. For example, For example, when it is 100 milliseconds, It can be set to 1 millisecond. However, the above example is only for better illustration of this application, and the implementation of this application is not limited to this.

[0070] In an alternative example, based on the second embodiment, in the first standby state S1, the detection switch K1 can be controlled to periodically conduct, wherein in each cycle, the conduction duration of the second detection circuit 142 is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit 142 is greater than or equal to a preset duty cycle. The switching cycles of detection switches K1 and K2 are, for example, both less than a first threshold. Furthermore, the switching cycles of detection switches K1 and K2 are synchronized. For example, when the device to be charged is a power bank, the conduction time of detection switch K1 within the switching cycle is, for example, 50ms~100ms, and the conduction duty cycle of detection switch K1 is, for example, 30%~70%. Further, in this embodiment, the conduction duration of detection switch K1 in each switching cycle... The time should be greater than 20 milliseconds, and the duty cycle of the detection switch K1 in each switching cycle should be greater than 50%. This is to avoid the risk that the power adapter may not be able to recognize the connected device.

[0071] In the third embodiment of this application, the difference from the second embodiment is that, in the first standby state S1, the first detection circuit 141 operates periodically (i.e., the detection switch K2 is periodically turned on), and the operating current Is1 of the first detection circuit 141 in the first standby state S1 is equal to the operating current Is2 of the first detection circuit 141 in the normal state S2. This reduces the power consumption of the second pull-down resistor Ra in the charging cable 200 connected to the power adapter in the first standby state S1.

[0072] For example, such as Figure 8 As shown, the state machine 143 switches to the first standby state S1, and the corresponding output control signal GR indicates that the control detection switch K1 is normally on and the detection switch K2 is periodically on, and makes the operating current Is1 of the first detection circuit 141 equal to the operating current Is2 of the first detection circuit 141 under normal conditions.

[0073] In an alternative example, based on the third embodiment, in the first standby state S1, the detection switch K1 can also be controlled to be periodically turned on, wherein in each cycle, the conduction duration of the second detection circuit 142 is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit 142 is greater than or equal to a preset duty cycle.

[0074] Figure 9 This diagram illustrates a standby detection method for a power adapter provided in an embodiment of the present disclosure.

[0075] like Figure 9As shown, the standby detection method includes the following steps:

[0076] Step S410: Switch the working state of the power adapter according to the connection status of the charging cable and the device to be charged.

[0077] Step S420: In the first standby state, control the reduction of the average current of the first detection circuit. Specifically, in the first standby state, control the average current of the first detection circuit to be less than the average current of the first detection circuit in the normal state.

[0078] Further, step S420 includes: controlling the first detection circuit to continue working in the first standby state, and the working current is less than the preset current.

[0079] In an alternative embodiment, step S420 includes: controlling the first detection circuit to operate periodically in the first standby state, and the operating current is less than or equal to a preset current.

[0080] The preset current is the operating current of the first detection circuit when the power adapter is working normally. Under normal conditions, the interface unit is connected to the device to be charged by inserting a charging cable.

[0081] Furthermore, the standby detection method also includes: controlling the second detection circuit to operate continuously in the first standby state; or controlling the second detection circuit to operate periodically in the first standby state, wherein in each cycle, the conduction duration of the second detection circuit is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit is greater than or equal to a preset duty cycle.

[0082] Furthermore, the standby detection method also includes: controlling the first detection circuit and the second detection circuit to continue working in the second standby state, wherein the interface unit disconnects the charging cable and is not connected to the device to be charged in the second standby state.

[0083] Furthermore, the standby detection method also includes: controlling the power switch to turn off in the first standby state and the second standby state, wherein the power switch is connected between the output terminal and the interface unit.

[0084] Furthermore, the standby detection method also includes: detecting the pull-down resistor of the first detection circuit when the charging cable is connected or disconnected to determine whether the interface unit is connected or disconnected from the charging cable; and detecting the pull-down resistor of the second detection circuit when the device to be charged is connected or disconnected to determine whether the interface unit is connected or disconnected from the device to be charged.

[0085] Further, step S410 includes: controlling the device to enter a second standby state when the first detection circuit detects that the charging cable has been removed; controlling the device to be charged to enter a normal state when the second detection circuit detects that the device to be charged has been connected; and controlling the device to enter a first standby state when the first detection circuit detects that the charging cable has been inserted and the second detection circuit detects that the device to be charged has not been connected.

[0086] The power adapter and its control circuit, standby detection circuit and method provided in this disclosure can reduce the average current flowing through the pull-down resistor of the charging cable by controlling and reducing the average current of the first detection circuit in the first standby state, thereby reducing the standby power consumption in the first standby state.

[0087] This disclosure also includes maintaining the second detection circuit on in the first standby state. Alternatively, it may periodically activate the second detection circuit, with the activation duration of the second detection circuit being greater than or equal to a preset duration and the duty cycle of the second detection circuit being greater than or equal to a preset duty cycle within each cycle. This ensures that the connection status of the charging cable and the device to be charged can be effectively detected.

[0088] The power adapter and its control circuit, standby detection circuit and method disclosed herein reduce standby power consumption in the first standby state by controlling the first detection circuit to operate continuously in a first standby state, with the operating current being less than a preset current; or by controlling the first detection circuit to operate periodically, with the operating current being less than or equal to a preset current.

[0089] Furthermore, in the second standby state, this disclosure controls the second detection circuit to remain on and controls the first detection circuit to remain on, so as to ensure that the connection status of the charging cable and the device to be charged can be effectively detected.

[0090] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A standby detection method for a power adapter, wherein the output terminal of the power adapter is provided with an interface unit, and the interface unit is connected to a device to be charged via a pluggable charging cable, characterized in that, include: The power adapter's operating state is switched according to the connection status of the charging cable and the device to be charged; In the first standby state, the average current of the first detection circuit is reduced. The first detection circuit is used to detect whether the interface unit is inserted into or unplugged from the charging cable. In the first standby state, the interface unit is inserted into the charging cable but not connected to the device to be charged.

2. The standby detection method according to claim 1, characterized in that, Controlling the reduction of the average current of the first detection circuit in the first standby state includes: In the first standby state, the first detection circuit is controlled to work continuously, and the working current is less than the preset current.

3. The standby detection method according to claim 1, characterized in that, Controlling the reduction of the average current of the first detection circuit in the first standby state includes: In the first standby state, the first detection circuit is controlled to work periodically, and the working current is less than or equal to the preset current.

4. The standby detection method according to claim 2 or 3, characterized in that, The preset current is the operating current of the first detection circuit when the power adapter is in normal working condition, in which the interface unit is connected to the device to be charged by inserting the charging cable.

5. The standby detection method according to claim 1, characterized in that, Also includes: In the first standby state, the second detection circuit is controlled to work continuously. The second detection circuit is used to detect whether the interface unit is inserted into or removed from the device to be charged.

6. The standby detection method according to claim 1, characterized in that, Also includes: In the first standby state, the second detection circuit is controlled to operate periodically. The second detection circuit is used to detect whether the interface unit is inserted into or removed from the device to be charged. In each cycle, the conduction duration of the second detection circuit is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit is greater than or equal to a preset duty cycle.

7. The standby detection method according to claim 1, characterized in that, Also includes: In the second standby state, the first and second detection circuits are kept running continuously. The second detection circuit is used to detect whether the interface unit is inserted into or removed from the device to be charged. In the second standby state, the interface unit disconnects the charging cable and is not connected to the device to be charged.

8. The standby detection method according to claim 1, characterized in that, Also includes: In the first standby state and the second standby state, the power switch is turned off, wherein the power switch is connected between the output terminal and the interface unit.

9. The standby detection method according to claim 5 or 6, characterized in that, Also includes: The pull-down resistor of the first detection circuit is connected or disconnected from the charging cable to determine whether the interface unit is connected or disconnected from the charging cable. as well as The second detection circuit is used to detect whether the pull-down resistor of the device to be charged is connected or disconnected, in order to determine whether the interface unit is connected or disconnected from the device to be charged.

10. The standby detection method according to claim 5 or 6, characterized in that, Switching the operating state of the power adapter based on the connection status of the charging cable and the device to be charged includes: If the first detection circuit detects that the charging cable has been removed, the system will control the system to enter a second standby state. When the second detection circuit detects that the device to be charged is connected, the system is controlled to enter a normal state; and When the first detection circuit detects that the charging cable is inserted and the second detection circuit detects that the device to be charged is not connected, the system is controlled to enter the first standby state.

11. A standby detection circuit for a power adapter, wherein the output terminal of the power adapter is provided with an interface unit, the interface unit being connected to a device to be charged via a pluggable charging cable, characterized in that, include: A first detection circuit is connected to the output terminal to be powered and connected to the interface unit to detect whether the charging cable is inserted into or removed from the interface unit. The state machine switches the operating state of the power adapter according to the connection status of the charging cable and the device to be charged, and controls the reduction of the average current of the first detection circuit in the first standby state. In the first standby state, the interface unit is inserted into the charging cable but not connected to the device to be charged.

12. The standby detection circuit according to claim 11, characterized in that, The state machine controls the first detection circuit to remain on in the first standby state, and the operating current is less than a preset current, or In the first standby state, the state machine controls the first detection circuit to be periodically turned on, and the operating current is less than or equal to a preset current. The preset current is the operating current of the first detection circuit when the power adapter is in normal working condition, and in normal working condition, the interface unit is connected to the device to be charged by inserting the charging cable.

13. The standby detection circuit according to claim 11, characterized in that, Also includes: The second detection circuit is connected to the output terminal to be powered, and connected to the interface unit to detect whether the device to be charged is inserted into or removed from the interface unit. In the first standby state, the state machine controls the second detection circuit to operate continuously. Alternatively, the state machine controls the second detection circuit to operate periodically. In each cycle, the conduction duration of the second detection circuit is greater than or equal to a preset duration, and the conduction duty cycle of the second detection circuit is greater than or equal to a preset duty cycle.

14. The standby detection circuit according to claim 11, characterized in that, The interface unit includes two detection interfaces, and each detection interface is connected to a detection circuit via a connection to the output terminal of the power adapter. One detection interface corresponds to the pull-down resistor in the charging cable, and the other detection interface corresponds to the pull-down resistor in the device to be charged. The detection circuit connected to the detection interface corresponding to the pull-down resistor in the charging cable is the first detection circuit, and the detection circuit connected to the detection interface corresponding to the pull-down resistor in the device to be charged is the second detection circuit. The second detection circuit is used to detect whether the interface unit is inserted into or removed from the device to be charged.

15. The standby detection circuit according to claim 14, characterized in that, Each detection circuit includes a detection switch and a detection resistor connected in series. In the first standby state, the first detection circuit is connected to a pull-down resistor in the charging cable via a detection interface.

16. A control circuit for a power adapter, characterized in that, Includes the standby detection circuit as described in any one of claims 11-15.

17. A power adapter, characterized in that, include: Output terminal; Power switch; A voltage converter that converts AC input voltage into DC output voltage and outputs it via the output terminal; The interface unit is connected to the output terminal via the power switch; and The control circuit as described in claim 16.

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