Electronic equipment and protection circuit and protection method thereof

Abstract

The invention provides electronic equipment and a protection circuit and a protection method thereof, and belongs to the technical field of electronics. The protection circuit comprises a power supply control sub-circuit and a first protection sub-circuit. Wherein the first protection sub-circuit can transmit a starting control signal to the switch control end when monitoring that the voltage of a power supply signal provided by the power supply end is within a voltage protection threshold range, that is, the power supply signal does not have undervoltage or overvoltage, so that the power supply control sub-circuit reliably controls the power supply end to be conducted with the output end; the power supply supplies power to a load coupled to the output end based on the power supply signal. The first protection sub-circuit can transmit a turn-off control signal to the switch control end when monitoring that the voltage of a power supply signal provided by the power supply end is out of a voltage protection threshold range, that is, the power supply signal is under-voltage or over-voltage, so that the power supply control sub-circuit timely controls the power supply end to be disconnected from the output end, and the power supply end is protected from being disconnected from the output end. Therefore, the under-voltage protection or the over-voltage protection is realized.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic technology, and in particular to an electronic device and a protection circuit and a protection method thereof. Background Art

[0002] At present, the development and application of electronic devices have exploded and become an indispensable part of people's lives. In the process of using electronic devices, they often need to be charged by power supply. During the charging process, due to a series of factors, overvoltage, undervoltage or other problems will inevitably occur, which may damage the electronic devices in serious cases. Therefore, electrical safety has become the core of the design of electronic devices. Summary of the invention

[0003] Provided is an electronic device and a protection circuit and a protection method thereof, which can solve the problem of electricity safety in related technologies. The technical solution is as follows:

[0004] In one aspect, a protection circuit of an electronic device is provided, the protection circuit comprising: a power supply control subcircuit and a first protection subcircuit;

[0005] The power supply control subcircuit is coupled to the switch control terminal, the power supply terminal and the output terminal respectively, and the output terminal is used to couple the load; the power supply control subcircuit is used to control the power supply terminal to be connected with the output terminal in response to the start control signal provided by the switch control terminal, so as to supply power to the load based on the power supply signal provided by the power supply terminal, and to control the power supply terminal to be disconnected from the output terminal in response to the shutdown control signal provided by the switch control terminal;

[0006] The first protection subcircuit is coupled to a reference power supply terminal, the power supply terminal and the switch control terminal respectively; the reference power supply terminal is used to transmit a reference power supply signal to the first protection subcircuit; the first protection subcircuit is used to transmit a start control signal to the switch control terminal in response to the voltage of the power supply signal being within a voltage protection threshold range; and to transmit a shutdown control signal to the switch control terminal in response to the voltage of the power supply signal being outside the voltage protection threshold range.

[0007] Optionally, the first protection subcircuit includes: a first monitoring unit and a first comparing unit;

[0008] The first monitoring unit is coupled to the reference power supply terminal, the power supply terminal, and the first input terminal and the second input terminal of the first comparison unit respectively; the reference power supply terminal is used to transmit a reference power supply signal to the first monitoring unit; the first monitoring unit is used to transmit a first indication signal to the first input terminal and the second input terminal of the first comparison unit in response to the voltage of the power supply signal being within the voltage protection threshold range, and to transmit a second indication signal to the first input terminal and the second input terminal of the first comparison unit in response to the voltage of the power supply signal being outside the voltage protection threshold range;

[0009] The output end of the first comparison unit is coupled to the switch control end; the first comparison unit is used to transmit an on control signal to the switch control end in response to the first indication signal; and to transmit an off control signal to the switch control end in response to the second indication signal.

[0010] Optionally, the first monitoring unit includes: a voltage dividing subunit, a charging and discharging electronic unit and a voltage stabilizing subunit;

[0011] The voltage divider unit is coupled to the reference power supply terminal, the power supply terminal, the first node and the second node respectively; the reference power supply terminal is used to transmit a reference power supply signal to the voltage divider unit; the voltage divider unit is used to transmit the reference power supply signal to the first node after voltage division processing, and transmit the power supply signal to the second node after voltage division processing;

[0012] The charge-discharge electronic unit is coupled to the first node, the second node, the first input terminal and the second input terminal of the first comparison unit respectively; the charge-discharge electronic unit is used to transmit a first indication signal or a second indication signal to the first input terminal and the second input terminal of the first comparison unit based on the potential of the first node and the potential of the second node;

[0013] The voltage stabilizing subunit is coupled to the first node and the power supply terminal respectively; the voltage stabilizing subunit is used to control the potential of the first node based on the potential of the first node and the power supply signal.

[0014] Optionally, the voltage dividing subunit includes: a first resistor, a second resistor, a third resistor and a fourth resistor;

[0015] The first end of the first resistor is coupled to the reference power supply end; the second end of the first resistor is coupled to the first end of the second resistor and coupled to the first node; the second end of the second resistor is grounded;

[0016] The first end of the third resistor is coupled to the power supply end; the second end of the third resistor is coupled to the first end of the fourth resistor and to the second node; the second end of the fourth resistor is grounded.

[0017] Optionally, the charging and discharging electronic unit includes: a first capacitor and a second capacitor;

[0018] The first terminal of the first capacitor is coupled to the first node and to the first input terminal of the first comparison unit; the second terminal of the first capacitor is grounded;

[0019] A first terminal of the second capacitor is coupled to the second node and to the second input terminal of the first comparison unit; a second terminal of the second capacitor is grounded.

[0020] Optionally, the voltage stabilizing subunit includes: a voltage stabilizing diode;

[0021] The input end of the voltage stabilizing diode is coupled to the first node, and the output end of the voltage stabilizing diode is coupled to the power supply end.

[0022] Optionally, the first comparison unit includes: a first comparator;

[0023] The non-inverting input terminal and the inverting input terminal of the first comparator are respectively coupled to the first monitoring unit as the first input terminal and the second input terminal of the first comparison unit, and the output terminal of the first comparator is coupled to the switch control terminal as the output terminal of the first comparison unit.

[0024] Optionally, the protection circuit further includes: a second protection subcircuit;

[0025] The second protection subcircuit is coupled to the load, the reference power supply terminal and the first protection subcircuit respectively; the reference power supply terminal is also used to transmit a reference power supply signal to the second protection subcircuit; the second protection subcircuit is used to transmit a third indication signal to the first protection subcircuit in response to a load current flowing through the load being greater than an overcurrent protection threshold; and transmit a fourth indication signal to the first protection subcircuit in response to the load current being less than the overcurrent protection threshold;

[0026] The first protection subcircuit is used to transmit a shutdown control signal to the switch control end in response to the third indication signal, and to transmit a start control signal to the switch control end in response to the voltage of the fourth indication signal and the power supply signal being within a voltage protection threshold range, and to transmit a shutdown control signal to the switch control end in response to the voltage of the fourth indication signal and the power supply signal being outside the voltage protection threshold range.

[0027] Optionally, the first protection subcircuit includes: a first monitoring unit and a first comparing unit; the second protection subcircuit includes: a second monitoring unit and a second comparing unit;

[0028] The second monitoring unit is coupled to the load and the first input terminal of the second comparing unit respectively; the second monitoring unit is used to collect the load current and transmit an input signal to the first input terminal of the second comparing unit based on the load current;

[0029] The second input terminal of the second comparison unit is also coupled to the reference power supply terminal, and the output terminal of the second comparison unit is coupled to the second input terminal of the first comparison unit in the first protection sub-circuit; the reference power supply terminal is also used to transmit a reference power supply signal to the second input terminal of the second comparison unit; the second comparison unit is used to transmit the third indication signal to the second input terminal of the first comparison unit in response to the load current being greater than the overcurrent protection threshold, and to transmit the fourth indication signal to the second input terminal of the first comparison unit in response to the load current being less than the overcurrent protection threshold.

[0030] Optionally, the second monitoring unit includes: a sampling resistor;

[0031] The first end of the sampling resistor is coupled to the load and the first input end of the second comparison unit respectively; the second end of the sampling resistor is grounded.

[0032] Optionally, the second comparison unit includes: a second comparator;

[0033] The inverting input terminal of the second comparator is coupled to the second monitoring unit as the first input terminal of the second comparison unit, the non-inverting input terminal of the second comparator is coupled to the reference power supply terminal as the second input terminal of the second comparison unit, and the output terminal of the second comparator is coupled to the second input terminal of the first comparison unit in the first protection sub-circuit as the output terminal of the second comparison unit.

[0034] Optionally, the second protection subcircuit further includes: a filtering unit and a voltage dividing unit;

[0035] The filtering unit is coupled to the first input terminals of the second monitoring unit and the second comparing unit respectively; the filtering unit is used to filter the input signal transmitted by the second monitoring unit and transmit it to the first input terminal of the second comparing unit;

[0036] The voltage dividing unit is coupled to the reference power supply terminal and the second input terminal of the second comparison unit respectively; the voltage dividing unit is used for transmitting the reference power supply signal to the second input terminal of the second comparison unit after voltage division processing.

[0037] Optionally, the filtering unit includes: a fifth resistor and a third capacitor;

[0038] The first end of the fifth resistor is coupled to the second monitoring unit; the second end of the fifth resistor is coupled to the first end of the third capacitor, and both are coupled to the first input end of the second comparing unit; the second end of the third capacitor is grounded.

[0039] Optionally, the voltage dividing unit includes: a sixth resistor and a seventh resistor;

[0040] The first end of the sixth resistor is coupled to the reference power supply end; the second end of the sixth resistor is coupled to the first end of the seventh resistor, and both are coupled to the second input end of the second comparison unit; the second end of the seventh resistor is grounded.

[0041] Optionally, the power supply control subcircuit includes: an eighth resistor, a ninth resistor and a switch transistor;

[0042] The gate of the switching transistor is coupled to the switch control end through the eighth resistor, and is also coupled to the first end of the ninth resistor; the second end of the ninth resistor is coupled to the first electrode of the switching transistor, and is coupled to the power supply end; the second electrode of the switching transistor is coupled to the output end.

[0043] In another aspect, a method for protecting an electronic device is provided, which is applied to the protection circuit as described in the above aspect; the method comprises:

[0044] The first protection sub-circuit receives a reference power signal provided by the reference power terminal, and monitors a power supply signal provided by the power supply terminal;

[0045] In response to the voltage of the power supply signal being within the voltage protection threshold range, the first protection subcircuit transmits a start control signal to the switch control terminal, driving the power supply control subcircuit to control the power supply terminal to be connected to the output terminal, so as to supply power to the load coupled to the output terminal based on the power supply signal;

[0046] In response to the voltage of the power supply signal being outside the voltage protection threshold range, the first protection subcircuit transmits a shutdown control signal to the switch control terminal to drive the power supply control subcircuit to control the power supply terminal to be disconnected from the output terminal.

[0047] Optionally, the method further includes:

[0048] The second protection subcircuit receives the reference power supply signal and monitors the load current flowing through the load;

[0049] In response to the load current being greater than the overcurrent protection threshold, the second protection subcircuit transmits a third indication signal to the first protection subcircuit, driving the first protection subcircuit to transmit a shutdown control signal to the switch control terminal;

[0050] In response to the load current being less than an overcurrent protection threshold, the second protection subcircuit transmits a fourth indication signal to the first protection subcircuit;

[0051] The first protection subcircuit transmits a start control signal to the switch control terminal in response to the voltage of the power supply signal being within the voltage protection threshold range, including:

[0052] The first protection subcircuit transmits a start control signal to the switch control terminal in response to the fourth indication signal and the voltage of the power supply signal being within a voltage protection threshold range;

[0053] The first protection subcircuit transmits a shutdown control signal to the switch control terminal in response to the voltage of the power supply signal being outside the voltage protection threshold range, including:

[0054] In response to the fourth indication signal and the voltage of the power supply signal being outside a voltage protection threshold range, the first protection subcircuit transmits a shutdown control signal to the switch control terminal.

[0055] In yet another aspect, an electronic device is provided, comprising: a device body, and a protection circuit as described in the above aspect located in the device body.

[0056] In summary, the beneficial effects brought about by the technical solution provided by the present disclosure may at least include:

[0057] An electronic device and its protection circuit and protection method are provided. The protection circuit includes: a power supply control subcircuit and a first protection subcircuit. Among them, the first protection subcircuit can transmit a start control signal to the switch control end when it is monitored that the voltage of the power supply signal provided by the power supply end is within the voltage protection threshold range, that is, the power supply signal is not under-voltage or over-voltage, so that the power supply control subcircuit can reliably control the power supply end and the output end to be connected, so as to supply power to the load coupled to the output end based on the power supply signal. And, the first protection subcircuit can transmit a shutdown control signal to the switch control end when it is monitored that the voltage of the power supply signal provided by the power supply end is outside the voltage protection threshold range, that is, the power supply signal is under-voltage or over-voltage, so that the power supply control subcircuit can promptly control the power supply end to disconnect the coupling with the output end, and no longer continue to supply power to the load, so as to achieve under-voltage protection or over-voltage protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] Figure 1 is a structural schematic diagram of a protection circuit provided by an embodiment of the present disclosure;

[0060] Figure 2 is a schematic diagram of the structure of another protection circuit provided by an embodiment of the present disclosure;

[0061] Figure 3 is a structural schematic diagram of another protection circuit provided by an embodiment of the present disclosure;

[0062] Figure 4 is a structural schematic diagram of another protection circuit provided by an embodiment of the present disclosure;

[0063] Figure 5 is a circuit structure diagram of a protection circuit provided by an embodiment of the present disclosure;

[0064] Figure 6 is a block diagram of a protection circuit provided by an embodiment of the present disclosure;

[0065] Figure 7 This is a schematic diagram of the working state of a protection circuit during normal operation provided by an embodiment of the present disclosure;

[0066] Figure 8 This is a schematic diagram of the working state of an overcurrent protection circuit provided by an embodiment of the present disclosure;

[0067] Fig. 9 This is a schematic diagram of the working state of an undervoltage protection circuit provided by an embodiment of the present disclosure;

[0068] Fig.10 This is a schematic diagram of the working state of an overvoltage protection circuit provided by an embodiment of the present disclosure;

[0069] Fig.11 is a flowchart of a protection method provided by an embodiment of the present disclosure;

[0070] Fig.12 is a flowchart of another protection method provided by an embodiment of the present disclosure;

[0071] Fig.13 is a flowchart of another protection method provided by an embodiment of the present disclosure;

[0072] Fig.14It is a structural schematic diagram of an electronic device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0073] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0074] At present, in order to solve other problems such as overvoltage, undervoltage or overcurrent, overvoltage protection, undervoltage protection / overcurrent protection modules are commonly used in circuit design. The electrical parameters of circuit devices with the above protection functions are fixed, the adjustable range is small, and the applicable scenarios are few. In addition, it is often necessary to use software for control, which has high requirements for use, a long development cycle, and relatively high costs. In short, the current protection modules do not have good versatility and compatibility.

[0075] Based on this, the embodiments of the present disclosure provide a protection circuit with adjustable parameters, low price, high circuit sensitivity, rapid and reliable response, and easy design to develop and implement, so as to achieve better protection effect.

[0076] Figure 1 Schematic diagram of a protection circuit of an electronic device provided by an embodiment of the present disclosure. Figure 1 As shown, the protection circuit includes: a power supply control subcircuit 01 and a first protection subcircuit 02 .

[0077] The power supply control subcircuit 01 is coupled to the switch control terminal K1, the power supply terminal Vin and the output terminal Vout respectively, and the output terminal Vout is used to couple the load RL. The power supply control subcircuit 01 is used to control the power supply terminal Vin and the output terminal Vout to be connected in response to the start control signal provided by the switch control terminal K1, so as to supply power to the load RL based on the power supply signal provided by the power supply terminal Vin, and to control the power supply terminal Vin to be disconnected from the output terminal Vout in response to the shutdown control signal provided by the switch control terminal K1.

[0078] Based on the above embodiments, it can be known that the load RL can be any product that needs to be charged, such as a mobile phone, a computer or an electric car. Accordingly, the types of electronic devices to which the protection circuit can be applied can be: charging piles, battery protection boards, TV power boards, light source driver boards or mobile electronic devices and other products with power supply functions.

[0079] Continue to refer Figure 1It can be seen that the first protection subcircuit 02 is coupled to the reference power terminal Vcc, the power supply terminal Vin and the switch control terminal K1 respectively. The reference power supply terminal Vcc is used to transmit a reference power signal to the first protection subcircuit 02. The first protection subcircuit 02 is used to transmit a start control signal to the switch control terminal K1 in response to the voltage of the power supply signal being within the voltage protection threshold range; and to transmit a shut-down control signal to the switch control terminal K1 in response to the voltage of the power supply signal being outside the voltage protection threshold range.

[0080] Optionally, the voltage of the reference power signal provided by the reference power terminal Vcc may be a fixed voltage. The voltage protection threshold range may be an undervoltage protection threshold V UVLO and overvoltage protection threshold V OVLO Accordingly, assuming that the voltage of the power supply signal is Vin0, the voltage Vin0 of the power supply signal is outside the voltage protection threshold range and may include the following two states: (1) the voltage Vin0 of the power supply signal is less than the undervoltage protection threshold V UVLO (i.e., Vin0 <V UVLO ), the power supply signal provided by the power supply terminal Vin is undervoltage. (2) The voltage Vin0 of the power supply signal is greater than the overvoltage protection threshold V OVLO (i.e., Vin0>V OVLO ), the power supply signal provided by the power supply terminal Vin is over-voltage. The voltage Vin0 of the power supply signal is within the voltage protection threshold range, which means that the voltage Vin0 of the power supply signal is greater than or equal to the under-voltage protection threshold V UVLO And less than or equal to the overvoltage protection threshold V OVLO (i.e., V UVLO ≤Vin0≤V OVLO ), the power supply signal provided by the power supply terminal Vin does not have an overvoltage or undervoltage.

[0081] That is, the first protection subcircuit 02 can be set to determine whether undervoltage or overvoltage occurs based on the provided voltage protection threshold range. Specifically, the first protection subcircuit 02 detects that the voltage of the power supply signal is within the voltage protection threshold range (i.e., V UVLO ≤Vin0≤V OVLO), it can be determined that neither undervoltage nor overvoltage occurs. Then, the first protection subcircuit 02 can further transmit an on control signal to the switch control terminal K1, so that the power supply control subcircuit 01 can reliably control the power supply terminal Vin and the output terminal Vout to be turned on under the control of the on control signal, so as to supply power to the load RL based on the power supply signal provided by the power supply terminal Vin. And, the first protection subcircuit 02 detects that the voltage of the power supply signal is outside the voltage protection threshold range, and detects that the voltage of the power supply signal is less than the undervoltage protection threshold (that is, Vin0 <V UVLO ), it can be determined that undervoltage occurs; if the voltage of the power supply signal is greater than the overvoltage protection threshold (that is, Vin0>V OVLO ), it can be determined that overvoltage occurs. Then, the first protection subcircuit 02 can further transmit a shutdown control signal to the switch control terminal K1, so that the power supply control subcircuit 01 promptly controls the power supply terminal Vin to disconnect the output terminal Vout, so that the load RL is no longer powered when undervoltage or overvoltage occurs. Undervoltage protection is implemented for undervoltage, and overvoltage protection is implemented for overvoltage. Accordingly, the first protection subcircuit 02 can also be called an undervoltage / overvoltage protection structure.

[0082] In summary, an embodiment of the present disclosure provides a protection circuit for an electronic device. The protection circuit includes: a power supply control subcircuit and a first protection subcircuit. Among them, the first protection subcircuit can transmit a start control signal to the switch control terminal when it is monitored that the voltage of the power supply signal provided by the power supply terminal is within the voltage protection threshold range, that is, the power supply signal is not under-voltage or over-voltage, so that the power supply control subcircuit can reliably control the power supply terminal and the output terminal to be turned on, so as to supply power to the load coupled to the output terminal based on the power supply signal. And, the first protection subcircuit can transmit a shutdown control signal to the switch control terminal when it is monitored that the voltage of the power supply signal provided by the power supply terminal is outside the voltage protection threshold range, that is, the power supply signal is under-voltage or over-voltage, so that the power supply control subcircuit can promptly control the power supply terminal to disconnect the coupling with the output terminal, and no longer continue to supply power to the load, so as to achieve under-voltage protection or over-voltage protection.

[0083] Figure 2 FIG. 1 is a schematic diagram of another protection circuit provided by an embodiment of the present disclosure. Figure 2 As shown, in some embodiments, the protection circuit may further include: a second protection sub-circuit 03 .

[0084] The second protection subcircuit 03 can be coupled to the load RL, the reference power supply terminal Vcc and the first protection subcircuit 02 respectively. The reference power supply terminal Vcc can also be used to transmit a reference power supply signal to the second protection subcircuit 03. The second protection subcircuit 03 can be used to transmit a third indication signal to the first protection subcircuit 02 in response to the load current flowing through the load RL being greater than the overcurrent protection threshold; and to transmit a fourth indication signal to the first protection subcircuit 02 in response to the load current flowing through the load RL being less than the overcurrent protection threshold.

[0085] That is, in the embodiment of the present disclosure, another second protection subcircuit 03 may be provided based on the provided overcurrent protection threshold I OCP To determine whether there is overcurrent. Assuming the load current is I load , it can be known that if the second protection sub-circuit 03 detects I load >I OCP , it can be determined that an overcurrent occurs at this time, and a third indication signal is transmitted to the first protection sub-circuit 02; on the contrary, if the second protection sub-circuit 03 detects I load ≤I OCP , it can be determined that no overcurrent occurs at this time, and a fourth indication signal is transmitted to the first protection sub-circuit 02.

[0086] On this basis, for the first protection subcircuit 02, the first protection subcircuit 02 can be used to respond to the received third indication signal and directly transmit a shutdown control signal to the switch control terminal K1, so that the power supply control subcircuit 01 timely controls the power supply terminal Vin to be disconnected from the output terminal Vout, so that the load RL is no longer powered when overcurrent occurs, thereby achieving overcurrent protection. In other words, when overcurrent occurs, the first protection subcircuit 02 can ignore overvoltage or undervoltage. And, the first protection subcircuit 02 can be used to respond to the voltage of the received fourth indication signal and the power supply signal being within the voltage protection threshold range, transmit a start control signal to the switch control terminal K1; and respond to the voltage of the received fourth indication signal and the power supply signal being outside the voltage protection threshold range, transmit a shutdown control signal to the switch control terminal K1. That is, when there is no overcurrent, the first protection subcircuit 02 can consider undervoltage or overvoltage again, and transmit a shutdown control signal to the switch control terminal K1 to achieve undervoltage protection / overvoltage protection. Correspondingly, the second protection subcircuit 03 can also be called an overcurrent protection structure. In this way, better protection can be achieved.

[0087] Figure 3 FIG. 1 is a schematic diagram of another protection circuit provided by an embodiment of the present disclosure. Figure 3 As shown, the first protection sub-circuit 02 may include: a first monitoring unit 021 and a first comparing unit 022 .

[0088] The first monitoring unit 021 can be coupled to the reference power terminal Vcc, the power supply terminal Vin, the first input terminal and the second input terminal of the first comparison unit 022, respectively. The reference power terminal Vcc can be used to transmit a reference power signal to the first monitoring unit 021 in the first protection subcircuit 02. The first monitoring unit 021 can be used to transmit a first indication signal to the first input terminal and the second input terminal of the first comparison unit 022 in response to the voltage of the power supply signal being within the voltage protection threshold range, to indicate that neither undervoltage nor overvoltage occurs; and to transmit a second indication signal to the first input terminal and the second input terminal of the first comparison unit 022 in response to the voltage of the power supply signal being outside the voltage protection threshold range, to indicate that undervoltage / overvoltage occurs.

[0089] The output terminal Vout of the first comparison unit 022 can be coupled to the switch control terminal K1. The first comparison unit 022 can be used to transmit a start control signal to the switch control terminal K1 in response to the received first indication signal (i.e., when neither undervoltage nor overvoltage occurs); and transmit a shutoff control signal to the switch control terminal K1 in response to the received second indication signal (i.e., when undervoltage / overvoltage occurs).

[0090] Optional, continue to refer to Figure 3 It can be seen that the second protection sub-circuit 03 may include: a second monitoring unit 031 and a second comparing unit 032 .

[0091] The second monitoring unit 031 may be coupled to the load RL and the first input terminal of the second comparison unit 032 respectively. The second monitoring unit 031 may be used to collect the load current flowing through the load RL, and transmit an input signal based on the load current to the first input terminal of the second comparison unit 032. Here, the input signal may refer to a sampled voltage generated based on the load current.

[0092] The second input terminal of the second comparison unit 032 may also be coupled to the reference power terminal Vcc, and the output terminal Vout of the second comparison unit 032 may be coupled to the second input terminal of the first comparison unit 022 in the first protection sub-circuit 02. The second comparison unit 032 may be configured to transmit a third indication signal to the second input terminal of the first comparison unit 022 if it is determined based on the reference power signal and the received input signal that the load current is greater than the overcurrent protection threshold, and to transmit a fourth indication signal to the second input terminal of the first comparison unit 022 if it is determined based on the reference power signal and the received input signal that the load current is less than the overcurrent protection threshold.

[0093] Optional, Figure 4 FIG. 1 is a schematic diagram of a structure of another protection circuit provided by an embodiment of the present disclosure. Figure 4As shown, in some embodiments, the second protection subcircuit 03 may further include: a filtering unit 033 and a voltage dividing unit 034 .

[0094] The filter unit 033 may be coupled to the first input terminal of the second monitoring unit 031 and the second comparison unit 032 respectively. The filter unit 033 may be used to filter the input signal transmitted by the second monitoring unit 031 and transmit it to the first input terminal of the second comparison unit 032.

[0095] The voltage dividing unit 034 can be coupled to the reference power supply terminal Vcc and the second input terminal of the second comparison unit 032 respectively. The voltage dividing unit 034 can be used to divide the reference power supply signal and transmit it to the second input terminal of the second comparison unit 032.

[0096] Optional, continue to refer to Figure 4 It can also be seen that, in some embodiments, the first monitoring unit 021 may include: a voltage dividing subunit 0211 , a charging and discharging electronic unit 0212 , and a voltage stabilizing subunit 0213 .

[0097] The voltage divider subunit 0211 can be coupled to the reference power supply terminal Vcc, the power supply terminal Vin, the first node P1 and the second node P2 respectively. The reference power supply terminal Vcc can be used to transmit the reference power supply signal to the voltage divider subunit 0211 in the first monitoring unit 021. The voltage divider subunit 0211 can be used to transmit the reference power supply signal to the first node P1 after voltage division processing, and transmit the power supply signal to the second node P2 after voltage division processing.

[0098] The charge-discharge electronic unit 0212 may be respectively coupled to the first node P1, the second node P2, and the first input terminal and the second input terminal of the first comparison unit 022. The charge-discharge electronic unit 0212 may be used to transmit the first indication signal or the second indication signal to the first input terminal and the second input terminal of the first comparison unit 022 based on the potential of the first node P1 and the potential of the second node P2.

[0099] The voltage stabilizing subunit 0213 may be coupled to the first node P1 and the power supply terminal Vin, respectively. The voltage stabilizing subunit 0213 may be used to control the potential of the first node P1 based on the potential of the first node P1 and the power supply signal.

[0100] exist Figure 4 On the basis of Figure 5 FIG. 1 shows a circuit structure diagram of a protection circuit. Figure 5 As shown, the voltage dividing subunit 0211 in the first monitoring unit 021 may include: a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4.

[0101] The first end of the first resistor R1 can be coupled to the reference power supply terminal Vcc; the second end of the first resistor R1 can be coupled to the first end of the second resistor R2, and the second end of the first resistor R1 can be coupled to the first node P1; the second end of the second resistor R2 can be grounded.

[0102] The first end of the third resistor R3 can be coupled to the power supply terminal Vin; the second end of the third resistor R3 can be coupled to the first end of the fourth resistor R4, and the second end of the third resistor R3 can be coupled to the second node P2; the second end of the fourth resistor R4 can be grounded.

[0103] Optional, continue to refer to Figure 5 It can be seen that the charge and discharge electronic unit 0212 in the first monitoring unit 021 may include: a first capacitor C1 and a second capacitor C2.

[0104] A first end of the first capacitor C1 may be coupled to the first node P1 , and the first end of the first capacitor C1 may be coupled to the first input end of the first comparison unit 022 ; and a second end of the first capacitor C1 may be grounded.

[0105] A first end of the second capacitor C2 may be coupled to the second node P2, and the first end of the second capacitor C2 may be coupled to the second input end of the first comparison unit 022; and a second end of the second capacitor C2 may be grounded.

[0106] Optional, continue to refer to Figure 5 It can be seen that the voltage stabilizing subunit 0213 in the first monitoring unit 021 may include: a voltage stabilizing diode ZD1.

[0107] An input terminal of the Zener diode ZD1 may be coupled to the first node P1 , and an output terminal of the Zener diode ZD1 may be coupled to the power supply terminal Vin.

[0108] Optional, continue to refer to Figure 5 It can be seen that the first comparison unit 022 may include: a first comparator U1A.

[0109] The non-inverting input terminal (+) and the inverting input terminal (-) of the first comparator U1A can be coupled to the first monitoring unit 021 as the first input terminal and the second input terminal of the first comparison unit 022, respectively, and the output terminal Vout of the first comparator U1A can be coupled to the switch control terminal K1 as the output terminal Vout of the first comparison unit 022.

[0110] That is, in combination with the above embodiment records, reference Figure 5, the second end of the first resistor R1, the first end of the second resistor R2, the first end of the first capacitor C1, the input end of the Zener diode ZD1, and the non-inverting input end (+) of the first comparator U1A can be coupled to the first node P1. The second end of the third resistor R3, the first end of the fourth resistor R4, the first end of the second capacitor C2, and the inverting input end (-) of the first comparator U1A can be coupled to the second node P2.

[0111] Optional, continue to refer to Figure 5 It can be seen that the second monitoring unit 031 may include: a sampling resistor Rs.

[0112] A first terminal of the sampling resistor Rs may be respectively coupled to the load RL and the first input terminal of the second comparison unit 032. A second terminal of the sampling resistor Rs may be grounded.

[0113] Optional, continue to refer to Figure 5 It can be seen that the second comparison unit 032 may include: a second comparator U1B.

[0114] The inverting input terminal (-) of the second comparator U1B can be coupled to the second monitoring unit 031 as the first input terminal of the second comparison unit 032, the non-inverting input terminal (+) of the second comparator U1B can be coupled to the reference power supply terminal Vcc as the second input terminal of the second comparison unit 032, and the output terminal Vout of the second comparator U1B can be coupled to the second input terminal of the first comparison unit 022 in the first protection sub-circuit 02 as the output terminal Vout of the second comparison unit 032.

[0115] That is, in combination with the above embodiment records, reference Figure 5 The first end of the sampling resistor Rs can be coupled to the load RL and the inverting input terminal (-) of the second comparator U1B respectively. The output terminal Vout of the second comparator U1B can be coupled to the inverting input terminal (-) of the first comparator U1A.

[0116] Optional, continue to refer to Figure 5 It can be seen that the filtering unit 033 may include: a fifth resistor R5 and a third capacitor C3.

[0117] A first end of the fifth resistor R5 may be coupled to the second monitoring unit 031. A second end of the fifth resistor R5 and a first end of the third capacitor C3 may be coupled, and both may be coupled to the first input end of the second comparing unit 032. A second end of the third capacitor C3 may be grounded.

[0118] That is, in combination with the above embodiment records, reference Figure 5, the first end of the fifth resistor R5 can be coupled to the first end of the sampling resistor Rs. The second end of the fifth resistor R5 and the first end of the third capacitor C3 can both be coupled to the inverting input terminal (-) of the second comparator U1B. In other words, the first end of the sampling resistor Rs can be indirectly coupled to the inverting input terminal (-) of the second comparator U1B through the fifth resistor R5 and the third capacitor C3.

[0119] Optional, continue to refer to Figure 5 It can be seen that the voltage dividing unit 034 may include: a sixth resistor R6 and a seventh resistor R7.

[0120] The first end of the sixth resistor R6 can be coupled to the reference power supply terminal Vcc. The second end of the sixth resistor R6 and the first end of the seventh resistor R7 can be coupled and can both be coupled to the second input end of the second comparison unit 032. The second end of the seventh resistor R7 can be grounded.

[0121] That is, in combination with the above embodiment records, reference Figure 5 , the first end of the fifth resistor R5 can be coupled to the first end of the sampling resistor Rs. The second end of the sixth resistor R6 and the first end of the seventh resistor R7 can both be coupled to the non-inverting input terminal (+) of the second comparator U1B. In other words, the non-inverting input terminal (+) of the second comparator U1B can be indirectly coupled to the reference power supply terminal Vcc through the sixth resistor R6 and the seventh resistor R7.

[0122] Optional, continue to refer to Figure 5 It can be seen that the power supply control sub-circuit 01 may include: an eighth resistor R8, a ninth resistor R9 and a switch transistor Q1.

[0123] The gate of the switch transistor Q1 can be coupled to the switch control terminal K1 through the eighth resistor R8, and can also be coupled to the first end of the ninth resistor R9. The second end of the ninth resistor R9 and the first electrode of the switch transistor Q1 can be coupled, and both can be coupled to the power supply terminal Vin. The second electrode of the switch transistor Q1 can be coupled to the output terminal Vout.

[0124] Optionally, the switch transistor Q1 may be a metal-oxide-semiconductor (MOS) field effect transistor, referred to as a MOS transistor. The first electrode of the MOS transistor may be a source electrode, and the second electrode may be a drain electrode. Also, in some embodiments, the MOS transistor may be Figure 5For the PMOS transistor shown, it can be known that the potential of the on control signal received by the switch control terminal K1 can be a low potential relative to the potential of the off control signal. In some other embodiments, the MOS transistor can also be an NMOS transistor, and it can be known that the potential of the on control signal received by the switch control terminal K1 can be a high potential relative to the potential of the off control signal. Of course, this is only a schematic illustration.

[0125] Optional, continue to refer to Figure 5 It can be seen that the second comparator U1B can also be coupled to the power supply terminal Vin and can be grounded to work under the drive of the power supply signal provided by the power supply terminal Vin. The first comparator U1A is the same and will not be repeated. In addition, in the embodiment of the present disclosure, the first comparator U1A and the second comparator U1B can be two independent voltage comparators, and their internal output stage can be an open collector output. In the circuit design, the first comparator U1A and the second comparator U1B can belong to a dual comparator element. For this purpose, Figure 5 Only the coupling and grounding design between the second comparator U1B and the power supply terminal Vin are shown.

[0126] It should be noted that the above circuit structure division method is only a schematic illustration. In some other embodiments, other division methods may also be used. Figure 6 As shown in the block diagram, the power supply control subcircuit 01 can be regarded as a power supply control unit. The first monitoring unit 021 and the first comparison unit 022 can be uniformly divided into an undervoltage / overvoltage monitoring unit. The second comparison unit 032, the filter unit 033 and the voltage divider unit 034 can be uniformly divided into an overcurrent monitoring unit, and the second monitoring unit 031 can be divided into a load current sampling unit. Figure 6 The power input shown in the figure may refer to the input of the power supply signal provided by the power supply terminal Vin, and the power output may refer to the power supply signal output to the load via the output terminal Vout. Figure 6 It can be seen from the working paths of each unit that in the protection circuit provided by the embodiment of the present disclosure, the power supply control unit can realize power output based on the power supply input to supply power to the load. The undervoltage / overvoltage monitoring unit can control the operation of the power supply control unit based on the power supply signal input through the power supply, and realize undervoltage protection / overvoltage protection in time. The load current sampling unit can sample the load current. The overcurrent monitoring unit can indirectly control the operation of the power supply control unit through the undervoltage / overvoltage monitoring unit based on the sampled load current, and realize overcurrent protection in time.

[0127] That is, the protection circuit provided by the embodiment of the present disclosure may include: a power supply control unit, an undervoltage / overvoltage monitoring unit, an overcurrent monitoring unit and a load current sampling unit. Among them, the power supply control unit may include an eighth resistor R8, a ninth resistor R9 and a PMOS tube Q1. The undervoltage / overvoltage monitoring unit may include a first resistor R1 to a fourth resistor R4, a first capacitor C1 and a second capacitor C2, a Zener diode ZD1 and a first comparator U1A. The overcurrent monitoring unit may include a fifth resistor R5 to a seventh resistor R7, a third capacitor C3 and a second comparator U1B. The load current sampling unit may include a sampling resistor Rs.

[0128] Combination Figure 5 From the circuit structure shown, we can see that:

[0129] First, the non-inverting input terminal (+) of the first comparator U1A is coupled to the first capacitor C1. On this basis, when the voltage Vin0 of the power supply signal provided by the power supply terminal Vin is lower than the sum of the voltage divided by the first resistor R1 and the second resistor R2 and the voltage stabilization value Vz of the voltage stabilizing diode ZD1, the voltage Vin0 of the power supply signal provided by the power supply terminal Vin can charge the first capacitor C1 through the first resistor R1 and the second resistor R2, and charge to the voltage divided by the first resistor R1 and the second resistor R2 of the power supply signal Vin0; and when the voltage Vin0 of the power supply signal provided by the power supply terminal Vin is higher than the sum of the voltage divided by the first resistor R1 and the second resistor R2 and the voltage stabilization value Vz of the voltage stabilizing diode ZD1, the voltage Vin0 of the power supply signal provided by the power supply terminal Vin can charge the first capacitor C1 through the voltage stabilizing diode ZD1, and charge to the voltage value of the difference between the voltage Vin0 of the power supply signal and the voltage stabilization value Vz of the voltage stabilizing diode ZD1. Correspondingly, the voltage of the first capacitor C1 can act on the non-inverting input terminal (+) of the first comparator U1A. Thus, the voltage of at least one of the first resistor R1 and the second resistor R2 can be set to flexibly set the voltage division value through the first resistor R1 and the second resistor R2, as well as the charging time of the first capacitor C1. In addition, different types of voltage regulator diodes ZD1 can be selected to design different voltage regulation values.

[0130] Secondly, the inverting input terminal (-) of the first comparator U1A is coupled to the second capacitor C2, and is also coupled to the output terminal of the second comparator U1B. On this basis, when the output terminal of the second comparator U1B outputs a high potential, the power supply terminal Vin can charge the second capacitor C2 through the voltage division of the third resistor R3 and the fourth resistor R4. When the output terminal of the second comparator U1B outputs a low potential, the second capacitor C2 can be discharged through the second comparator U1B. Correspondingly, the voltage of the second capacitor C2 can act on the inverting input terminal (-) of the first comparator U1A. Thus, the resistance value of at least one of the third resistor R3 and the fourth resistor R4 can be set to flexibly set the voltage division value through the third resistor R3 and the fourth resistor R4, as well as the charging time of the second capacitor C2.

[0131] Third, the reference power supply signal provided by the reference power supply terminal Vcc can act on the in-phase input terminal (+) of the second comparator U1B through the sixth resistor R6 and the seventh resistor R7 voltage division, and the inverting input terminal (-) of the second comparator U1B is coupled to the third capacitor C3. On this basis, the power supply signal transmitted to the output terminal Vout through the switch transistor Q1 can charge the third capacitor C3 through the voltage division of the load RL and the sampling resistor Rs through the fifth resistor R5. Correspondingly, the voltage of the third capacitor C3 can act on the inverting input terminal (-) of the second comparator U1B. Thus, the voltage of at least one of the sixth resistor R6 and the seventh resistor R7 can be set to flexibly set the voltage division value through the sixth resistor R6 and the seventh resistor R7. In addition, the resistance value of the fifth resistor R5 can be set to flexibly set the charging time of the third capacitor C3.

[0132] Fourthly, when the gate voltage of the switch transistor Q1 (e.g., PMOS tube) is less than a certain value of the source voltage, the PMOS tube can be turned on. When the gate voltage of the switch transistor Q1 (e.g., PMOS tube) is equal to the source voltage, the PMOS tube can be turned off. Accordingly, for different types of PMOS tubes, the conduction condition can be met by setting the resistance value of at least one of the eighth resistor R8 and the ninth resistor R9.

[0133] Therefore, the required undervoltage protection threshold V can be set. UVLO , overvoltage protection threshold V OVLO and overcurrent protection threshold I OCP For example, let Rs0 represent the resistance of the sampling resistor Rs, Vs0 represent the voltage across the sampling resistor, and V U1A - represents the voltage at the inverting input terminal (-) of the first comparator U1A, V U1A+ The voltage at the non-inverting input terminal (+) of the first comparator U1A is represented by V U1B - represents the voltage at the inverting input terminal (-) of the second comparator U1B, VU1B+ represents the voltage of the non-inverting input terminal (+) of the second comparator U1B, Vin0 represents the voltage of the power supply signal, Vcc0 represents the voltage of the reference power supply signal, Vz represents the voltage value of the Zener diode ZD1, I load represents the load current, R10 represents the resistance of the first resistor R1, R20 represents the resistance of the second resistor R2, R30 represents the resistance of the third resistor R3, R40 represents the resistance of the fourth resistor R4, R50 represents the resistance of the fifth resistor R5, R60 represents the resistance of the sixth resistor R6, R70 represents the resistance of the seventh resistor R7, R80 represents the resistance of the eighth resistor R8, and R90 represents the resistance of the ninth resistor R9, then the following formula can be obtained:

[0134] V U1B- =Vs0=Rs0×I load Formula (1);

[0135]

[0136]

[0137]

[0138] According to the working principle of the comparator, when the output of the comparator changes, it can be set as:

[0139] V U1B- =V U1B+ Formula (5);

[0140] V U1A- =V U1A+ Formula (6);

[0141] From this we get:

[0142]

[0143]

[0144] Set the circuit parameters so that:

[0145]

[0146]

[0147] Combining formula (5) to formula (8), we can further get:

[0148]

[0149] When the circuit parameters satisfy the above formula (11), the protection circuit can have the undervoltage protection / overvoltage protection functions recorded in the above embodiment. In addition, the undervoltage protection threshold V can be further obtained by combining the above circuit parameter settings. UVLO , overvoltage protection threshold V OVLO and overcurrent protection threshold I OCP Satisfies the following formula:

[0150]

[0151] It can be seen from the above embodiments that: when V UVLO ≤Vin0≤V OVLO When Vin0 is on, the circuit outputs normally to supply power to the load RL. <V UVLO When Vin0>V OVLO When I load >I OCP When the circuit is overcurrent, the power supply to the load RL is stopped to achieve undervoltage protection / overvoltage protection / overcurrent protection.

[0152] Combined with the above-mentioned embodiment, and the working principle of the comparator: when the voltage at the non-inverting input terminal is greater than the voltage at the inverting input terminal, the output is a high potential; when the voltage at the non-inverting input terminal is less than the voltage at the inverting input terminal, the output is a low potential. The following embodiments illustrate the working principle of the protection circuit in different states one by one:

[0153] (1) Figure 7 The figure shows a schematic diagram of the working state of the protection circuit during normal operation. Figure 7 It can be seen that when there is no overcurrent, the voltage across the sampling resistor Rs can be within the normal range, and then, the voltage of the inverting input terminal of the second comparator U1B is less than the voltage of the non-inverting input terminal, and the second comparator U1B can output a high potential. Correspondingly, the voltage of the inverting input terminal of the first comparator U1A is positively correlated with the voltage Vin0 of the power supply signal provided by the power supply signal terminal Vin. At the same time, when there is no overvoltage and no undervoltage, the non-inverting input terminal and the inverting input terminal of the first comparator U1A can satisfy that the voltage of the non-inverting input terminal is less than the voltage of the inverting input terminal, and the first comparator U1A can output a low potential. That is, the potential of the signal transmitted to the switch control terminal K1 can be a low potential, and for the PMOS switch transistor Q1, the low potential signal can refer to a turn-on control signal. That is, at this time, the gate voltage of the switch transistor Q1 can be less than a certain value of the source voltage, satisfying the conduction condition, the switch transistor Q1 is turned on, and the power supply terminal Vin can reliably supply power to the load RL coupled to the output terminal Vout through the turned-on switch transistor Q1.

[0154] (2) Figure 8The figure shows a schematic diagram of the working state of an overcurrent protection circuit. Figure 8 It can be seen that when an overcurrent occurs, the voltage across the sampling resistor Rs increases, that is, it is not within the normal range, and then, the voltage at the inverting input terminal of the second comparator U1B will be greater than the voltage at the non-inverting input terminal, and the second comparator U1B can output a low potential. Correspondingly, the voltage at the inverting input terminal of the first comparator U1A is pulled down. At this time, regardless of whether it is undervoltage / overvoltage, the non-inverting input terminal and the inverting input terminal of the first comparator U1A can satisfy that the voltage at the non-inverting input terminal is greater than the voltage at the inverting input terminal, and the first comparator U1A can output a high potential. That is, the potential of the signal transmitted to the switch control terminal K1 can be a high potential, and for the PMOS switch transistor Q1, the high potential signal can refer to a shutdown control signal. That is, at this time, the gate voltage of the switch transistor Q1 is equal to the source voltage, and the conduction condition is not met, the switch transistor Q1 is turned off, and the load RL stops being powered.

[0155] (3) Fig. 9 The figure shows a schematic diagram of the working state of the undervoltage protection circuit. Fig. 9 It can be seen that when there is no overcurrent, the voltage across the sampling resistor Rs can be within the normal range, and then, the voltage of the inverting input terminal of the second comparator U1B is less than the voltage of the non-inverting input terminal, and the second comparator U1B can output a high potential. Correspondingly, the voltage of the inverting input terminal of the first comparator U1A is positively correlated with the voltage Vin0 of the power supply signal provided by the power supply signal terminal Vin. At this time, if undervoltage occurs, both the non-inverting input terminal and the inverting input terminal of the first comparator U1A can satisfy that the voltage of the non-inverting input terminal is greater than the voltage of the non-inverting input terminal, and the first comparator U1A can output a high potential. That is, the potential of the signal transmitted to the switch control terminal K1 can be a high potential, and for the PMOS switch transistor Q1, the high potential signal can refer to a shutdown control signal. That is, at this time, the gate voltage of the switch transistor Q1 is equal to the source voltage, and the conduction condition is not met, the switch transistor Q1 is turned off, and the load RL stops being supplied with power.

[0156] (4) Fig.10 The figure shows a schematic diagram of the working state of an overvoltage protection circuit. Fig.10It can be seen that when there is no overcurrent, the voltage across the sampling resistor Rs can be within the normal range, and then, the voltage of the inverting input terminal of the second comparator U1B is less than the voltage of the non-inverting input terminal, and the second comparator U1B can output a high potential. Correspondingly, the voltage of the inverting input terminal of the first comparator U1A is positively correlated with the voltage Vin0 of the power supply signal provided by the power supply signal terminal Vin. At this time, if an overvoltage occurs, the non-inverting input terminal and the inverting input terminal of the first comparator U1A can also satisfy that the voltage of the non-inverting input terminal is greater than the voltage of the inverting input terminal, and the first comparator U1A can output a high potential. That is, the potential of the signal transmitted to the switch control terminal K1 can be a high potential, and for the PMOS switch transistor Q1, the high potential signal can refer to a shutdown control signal. That is, at this time, the gate voltage of the switch transistor Q1 is equal to the source voltage, and the conduction condition is not met, the switch transistor Q1 is turned off, and the load RL stops being supplied with power.

[0157] That is, when undervoltage or overvoltage occurs, the voltage at the non-inverting input of the first comparator U1A will be higher than the voltage at the inverting input, and the output of the first comparator U1A will output a high-voltage signal to turn off the switch transistor Q1 and stop supplying power to the load RL, thereby achieving undervoltage protection / overvoltage protection. When overcurrent occurs, the voltage at the non-inverting input of the second comparator U1B will be lower than the voltage at the inverting input, and the output of the second comparator U1B will output a low-voltage signal, thereby pulling down the voltage at the inverting input of the first comparator U1A, and then the voltage at the non-inverting input of the first comparator U1A will be higher than the voltage at the inverting input, and the output of the first comparator U1A will continue to output a high-voltage signal to turn off the switch transistor Q1 and stop supplying power to the load RL, thereby achieving overcurrent protection. Furthermore, when there is no undervoltage, overvoltage or overcurrent, the voltage at the non-inverting input terminal of the second comparator U1B will be higher than the voltage at the inverting input terminal, and the output terminal of the second comparator U1B will output a high-voltage signal. The voltage at the non-inverting input terminal of the first comparator U1A will be lower than the voltage at the inverting input terminal, and the output terminal of the first comparator U1A will output a low-voltage signal to turn on the switching transistor Q1, thereby reliably supplying power to the load RL.

[0158] Of course, the second protection subcircuit 03 can be removed, that is, the overcurrent protection function can be removed, and the undervoltage protection / overvoltage protection function can be retained. Based on this circuit, more circuit forms can be expanded, and the ideas of current sampling detection, comparator signal processing, overvoltage protection, undervoltage protection and overcurrent protection are all within the scope of protection of the embodiments of the present disclosure. The above embodiment is only one of the optional embodiments of the present disclosure. The circuit framework based on this principle, including but not limited to modifying the parameters, models, packaging, specifications of the device, and equivalent substitution, are all within the scope of protection of the embodiments of the present disclosure.

[0159] It can be seen from the records of the above embodiments that the protection circuit provided by the embodiments of the present disclosure uses basic electronic components, which are low in cost, mature in application, and the parameters can be freely adjusted, with high sensitivity and strong versatility. In addition, it can have functions such as undervoltage protection, overvoltage protection and overcurrent protection, and has strong reusability. The overall design does not rely on software control, has a low development threshold, does not require human intervention, has a short development cycle, and is applicable to more scenarios.

[0160] In summary, an embodiment of the present disclosure provides a protection circuit for an electronic device. The protection circuit includes: a power supply control subcircuit and a first protection subcircuit. Among them, the first protection subcircuit can transmit a start control signal to the switch control terminal when it is monitored that the voltage of the power supply signal provided by the power supply terminal is within the voltage protection threshold range, that is, the power supply signal is not under-voltage or over-voltage, so that the power supply control subcircuit can reliably control the power supply terminal and the output terminal to be turned on, so as to supply power to the load coupled to the output terminal based on the power supply signal. And, the first protection subcircuit can transmit a shutdown control signal to the switch control terminal when it is monitored that the voltage of the power supply signal provided by the power supply terminal is outside the voltage protection threshold range, that is, the power supply signal is under-voltage or over-voltage, so that the power supply control subcircuit can promptly control the power supply terminal to disconnect the coupling with the output terminal, and no longer continue to supply power to the load, so as to achieve under-voltage protection or over-voltage protection.

[0161] Fig.11 1 is a flow chart of a method for protecting an electronic device provided by an embodiment of the present disclosure, and the method is applied to the protection circuit described in the above embodiment. Fig.11 As shown, the method includes:

[0162] Step 1101: A first protection sub-circuit receives a reference power signal provided by a reference power terminal, and monitors a power supply signal provided by a power supply terminal.

[0163] Step 1102, in response to the voltage of the power supply signal being within the voltage protection threshold range, the first protection sub-circuit transmits a start control signal to the switch control terminal, drives the power supply control sub-circuit to control the power supply terminal and the output terminal to be turned on, so as to supply power to the load coupled to the output terminal based on the power supply signal.

[0164] Step 1103: In response to the voltage of the power supply signal being outside the voltage protection threshold range, the first protection subcircuit transmits a shutdown control signal to the switch control terminal to drive the power supply control subcircuit to disconnect the power supply terminal from the output terminal.

[0165] Optionally, in some embodiments, reference Fig.12 As can be seen from another method flow chart, the protection method provided by the embodiment of the present disclosure may also include:

[0166] Step 1201: The second protection sub-circuit receives a reference power signal and monitors a load current flowing through a load.

[0167] Step 1202: In response to the load current being greater than the overcurrent protection threshold, the second protection subcircuit transmits a third indication signal to the first protection subcircuit, driving the first protection subcircuit to transmit a shutdown control signal to the switch control terminal.

[0168] Step 1203: In response to the load current being less than the overcurrent protection threshold, the second protection sub-circuit transmits a fourth indication signal to the first protection sub-circuit.

[0169] On the basis of executing step 1203, the above step 1102, i.e. the first protection sub-circuit transmits the start control signal to the switch control terminal in response to the voltage of the power supply signal being within the voltage protection threshold range, may include:

[0170] In response to the fourth indication signal and the voltage of the power supply signal being within the voltage protection threshold range, the first protection sub-circuit transmits a start control signal to the switch control terminal.

[0171] The above step 1103, in which the first protection sub-circuit transmits a shutdown control signal to the switch control terminal in response to the voltage of the power supply signal being outside the voltage protection threshold range, may include:

[0172] In response to the fourth indication signal and the voltage of the power supply signal being outside the voltage protection threshold range, the first protection sub-circuit transmits a shutdown control signal to the switch control terminal.

[0173] That is, combined Figure 6 As shown in the block diagram, refer to Fig.13 It can be seen from the flowchart of another protection method shown that in the embodiment of the present disclosure, after the power supply is input, the power supply signal can be monitored to see whether it is undervoltage / overvoltage. If the result is yes, the power supply to the load is stopped, that is, the power supply is turned off to achieve undervoltage protection / overvoltage protection. If the result is no, it is also detected whether the load current is overcurrent. If the result is yes, the power supply is turned off to achieve overcurrent protection. If the result is no, the load is powered, that is, normal power supply. After that, it can be continuously monitored whether there is overcurrent.

[0174] Since the protection method can have basically the same technical effect as the protection circuit described in the previous embodiment, for the purpose of brevity, the technical effect of the protection method will not be repeatedly described here.

[0175] Fig.14 Schematic diagram of the structure of an electronic device provided by an embodiment of the present disclosure. Fig.14 As shown, the electronic device includes: a device body 10, and a protection circuit 00 as described in the above embodiment located in the device body 10. Fig.14It can also be seen that the protection circuit 00 can be coupled to the output terminal Vout to flexibly control the power supply to the load coupled to the output terminal Vout.

[0176] Optionally, as described in the above embodiments, the electronic device may be any device with a power supply function, such as a charging device (eg, a charger, a charging pile), a power adapter, a motor drive device or a mobile electronic device.

[0177] It should be noted that the terms used in the embodiments of the present disclosure are only used to explain the embodiments and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be the common meanings understood by people with ordinary skills in the field to which the present disclosure belongs.

[0178] For example, the words "first", "second" or "third" and similar words used in the patent application specification and claims of this disclosure do not indicate any order, quantity or importance, but are merely used to distinguish different components.

[0179] When we say that an element is "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or intermediate elements may also be present. In addition, "connected" or "coupled" used herein may include wireless connection or wireless coupling.

[0180] Likewise, the words “a” or “an” and the like do not denote a limitation of quantity, but rather denote the presence of at least one.

[0181] “Including” or “comprising” and similar words mean that the elements or objects appearing before “including” or “comprising” include the elements or objects listed after “including” or “comprising” and their equivalents, and do not exclude other elements or objects.

[0182] “Up”, “down”, “left” or “right” etc. are only used to indicate relative position relationship. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0183] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A protection circuit for an electronic device, characterized in that: The protection circuit comprises: a power supply control subcircuit and a first protection subcircuit; The power supply control subcircuit is coupled to the switch control terminal, the power supply terminal and the output terminal respectively, and the output terminal is used to couple the load; the power supply control subcircuit is used to control the power supply terminal to be connected with the output terminal in response to the start control signal provided by the switch control terminal, so as to supply power to the load based on the power supply signal provided by the power supply terminal, and to control the power supply terminal to be disconnected from the output terminal in response to the shutdown control signal provided by the switch control terminal; The first protection subcircuit is coupled to a reference power supply terminal, the power supply terminal and the switch control terminal respectively; the reference power supply terminal is used to transmit a reference power supply signal to the first protection subcircuit; the first protection subcircuit is used to transmit a start control signal to the switch control terminal in response to the voltage of the power supply signal being within a voltage protection threshold range; and to transmit a shutdown control signal to the switch control terminal in response to the voltage of the power supply signal being outside the voltage protection threshold range.

2. The protection circuit according to claim 1, characterized in that: The first protection subcircuit comprises: a first monitoring unit and a first comparing unit; The first monitoring unit is coupled to the reference power supply terminal, the power supply terminal, and the first input terminal and the second input terminal of the first comparison unit respectively; the reference power supply terminal is used to transmit a reference power supply signal to the first monitoring unit; the first monitoring unit is used to transmit a first indication signal to the first input terminal and the second input terminal of the first comparison unit in response to the voltage of the power supply signal being within the voltage protection threshold range, and to transmit a second indication signal to the first input terminal and the second input terminal of the first comparison unit in response to the voltage of the power supply signal being outside the voltage protection threshold range; The output end of the first comparison unit is coupled to the switch control end; the first comparison unit is used to transmit an on control signal to the switch control end in response to the first indication signal; and to transmit an off control signal to the switch control end in response to the second indication signal.

3. The protection circuit according to claim 2, characterized in that: The first monitoring unit includes: a voltage dividing subunit, a charging and discharging electronic unit and a voltage stabilizing subunit; The voltage divider unit is coupled to the reference power supply terminal, the power supply terminal, the first node and the second node respectively; the reference power supply terminal is used to transmit a reference power supply signal to the voltage divider unit; the voltage divider unit is used to transmit the reference power supply signal to the first node after voltage division processing, and transmit the power supply signal to the second node after voltage division processing; The charge-discharge electronic unit is coupled to the first node, the second node, the first input terminal and the second input terminal of the first comparison unit respectively; the charge-discharge electronic unit is used to transmit a first indication signal or a second indication signal to the first input terminal and the second input terminal of the first comparison unit based on the potential of the first node and the potential of the second node; The voltage stabilizing subunit is coupled to the first node and the power supply terminal respectively; the voltage stabilizing subunit is used to control the potential of the first node based on the potential of the first node and the power supply signal.

4. The protection circuit according to claim 3, characterized in that: The voltage dividing subunit includes: a first resistor, a second resistor, a third resistor and a fourth resistor; The first end of the first resistor is coupled to the reference power supply end; the second end of the first resistor is coupled to the first end of the second resistor and coupled to the first node; the second end of the second resistor is grounded; The first end of the third resistor is coupled to the power supply end; the second end of the third resistor is coupled to the first end of the fourth resistor and to the second node; the second end of the fourth resistor is grounded.

5. The protection circuit according to claim 3, characterized in that: The charging and discharging electronic unit comprises: a first capacitor and a second capacitor; The first terminal of the first capacitor is coupled to the first node and to the first input terminal of the first comparison unit; the second terminal of the first capacitor is grounded; A first terminal of the second capacitor is coupled to the second node and to the second input terminal of the first comparison unit; a second terminal of the second capacitor is grounded.

6. The protection circuit according to claim 3, characterized in that: The voltage stabilizing subunit comprises: a voltage stabilizing diode; The input end of the voltage stabilizing diode is coupled to the first node, and the output end of the voltage stabilizing diode is coupled to the power supply end.

7. The protection circuit according to claim 2, characterized in that: The first comparison unit includes: a first comparator; The non-inverting input terminal and the inverting input terminal of the first comparator are respectively coupled to the first monitoring unit as the first input terminal and the second input terminal of the first comparison unit, and the output terminal of the first comparator is coupled to the switch control terminal as the output terminal of the first comparison unit.

8. The protection circuit according to any one of claims 1 to 7, characterized in that: The protection circuit further comprises: a second protection subcircuit; The second protection subcircuit is coupled to the load, the reference power supply terminal and the first protection subcircuit respectively; the reference power supply terminal is also used to transmit a reference power supply signal to the second protection subcircuit; the second protection subcircuit is used to transmit a third indication signal to the first protection subcircuit in response to a load current flowing through the load being greater than an overcurrent protection threshold; and transmit a fourth indication signal to the first protection subcircuit in response to the load current being less than the overcurrent protection threshold; The first protection subcircuit is used to transmit a shutdown control signal to the switch control end in response to the third indication signal, and to transmit a start control signal to the switch control end in response to the voltage of the fourth indication signal and the power supply signal being within a voltage protection threshold range, and to transmit a shutdown control signal to the switch control end in response to the voltage of the fourth indication signal and the power supply signal being outside the voltage protection threshold range.

9. The protection circuit according to claim 8, characterized in that: The first protection subcircuit includes: a first monitoring unit and a first comparing unit; the second protection subcircuit includes: a second monitoring unit and a second comparing unit; The second monitoring unit is coupled to the load and the first input terminal of the second comparing unit respectively; the second monitoring unit is used to collect the load current and transmit an input signal to the first input terminal of the second comparing unit based on the load current; The second input terminal of the second comparison unit is also coupled to the reference power supply terminal, and the output terminal of the second comparison unit is coupled to the second input terminal of the first comparison unit in the first protection sub-circuit; the reference power supply terminal is also used to transmit a reference power supply signal to the second input terminal of the second comparison unit; the second comparison unit is used to transmit the third indication signal to the second input terminal of the first comparison unit in response to the load current being greater than the overcurrent protection threshold, and to transmit the fourth indication signal to the second input terminal of the first comparison unit in response to the load current being less than the overcurrent protection threshold.

10. The protection circuit according to claim 9, characterized in that: The second monitoring unit includes: a sampling resistor; The first end of the sampling resistor is coupled to the load and the first input end of the second comparison unit respectively; the second end of the sampling resistor is grounded.

11. The protection circuit according to claim 9, characterized in that: The second comparison unit includes: a second comparator; The inverting input terminal of the second comparator is coupled to the second monitoring unit as the first input terminal of the second comparison unit, the non-inverting input terminal of the second comparator is coupled to the reference power supply terminal as the second input terminal of the second comparison unit, and the output terminal of the second comparator is coupled to the second input terminal of the first comparison unit in the first protection sub-circuit as the output terminal of the second comparison unit.

12. The protection circuit according to claim 9, characterized in that: The second protection subcircuit further includes: a filtering unit and a voltage dividing unit; The filtering unit is coupled to the first input terminals of the second monitoring unit and the second comparing unit respectively; the filtering unit is used to filter the input signal transmitted by the second monitoring unit and transmit it to the first input terminal of the second comparing unit; The voltage dividing unit is coupled to the reference power supply terminal and the second input terminal of the second comparison unit respectively; the voltage dividing unit is used for transmitting the reference power supply signal to the second input terminal of the second comparison unit after voltage division processing.

13. The protection circuit according to claim 12, characterized in that: The filtering unit comprises: a fifth resistor and a third capacitor; The first end of the fifth resistor is coupled to the second monitoring unit; the second end of the fifth resistor is coupled to the first end of the third capacitor, and both are coupled to the first input end of the second comparing unit; the second end of the third capacitor is grounded.

14. The protection circuit according to claim 12, characterized in that: The voltage dividing unit includes: a sixth resistor and a seventh resistor; The first end of the sixth resistor is coupled to the reference power supply end; the second end of the sixth resistor is coupled to the first end of the seventh resistor, and both are coupled to the second input end of the second comparison unit; the second end of the seventh resistor is grounded.

15. The protection circuit according to any one of claims 1 to 7, and 9 to 14, characterized in that: The power supply control subcircuit comprises: an eighth resistor, a ninth resistor and a switch transistor; The gate of the switching transistor is coupled to the switch control end through the eighth resistor, and is also coupled to the first end of the ninth resistor; the second end of the ninth resistor is coupled to the first electrode of the switching transistor, and is coupled to the power supply end; the second electrode of the switching transistor is coupled to the output end.

16. A method for protecting an electronic device, characterized in that: Applicable to the protection circuit according to any one of claims 1 to 15; the method comprises: The first protection sub-circuit receives a reference power signal provided by the reference power terminal, and monitors a power supply signal provided by the power supply terminal; In response to the voltage of the power supply signal being within the voltage protection threshold range, the first protection subcircuit transmits a start control signal to the switch control terminal, driving the power supply control subcircuit to control the power supply terminal to be connected to the output terminal, so as to supply power to the load coupled to the output terminal based on the power supply signal; In response to the voltage of the power supply signal being outside the voltage protection threshold range, the first protection subcircuit transmits a shutdown control signal to the switch control terminal to drive the power supply control subcircuit to control the power supply terminal to be disconnected from the output terminal.

17. The method according to claim 16, characterized in that The method further comprises: The second protection subcircuit receives the reference power supply signal and monitors the load current flowing through the load; In response to the load current being greater than the overcurrent protection threshold, the second protection subcircuit transmits a third indication signal to the first protection subcircuit, driving the first protection subcircuit to transmit a shutdown control signal to the switch control terminal; In response to the load current being less than an overcurrent protection threshold, the second protection subcircuit transmits a fourth indication signal to the first protection subcircuit; The first protection subcircuit transmits a start control signal to the switch control terminal in response to the voltage of the power supply signal being within the voltage protection threshold range, including: The first protection subcircuit transmits a start control signal to the switch control terminal in response to the fourth indication signal and the voltage of the power supply signal being within a voltage protection threshold range; The first protection subcircuit transmits a shutdown control signal to the switch control terminal in response to the voltage of the power supply signal being outside the voltage protection threshold range, including: In response to the fourth indication signal and the voltage of the power supply signal being outside a voltage protection threshold range, the first protection subcircuit transmits a shutdown control signal to the switch control terminal.

18. An electronic device, characterized in that: The electronic device comprises: a device body, and a protection circuit as claimed in any one of claims 1 to 15 located in the device body.

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