CN217824227U - Overcurrent detection circuit and electronic equipment - Google Patents

Abstract

The application provides an overcurrent detection circuit and electronic equipment, this overcurrent detection circuit includes: the control circuit is used for outputting a first level signal when the current flowing through the target circuit is smaller than a preset overcurrent value and outputting a second level signal when the current is larger than or equal to the preset overcurrent value; the first switch circuit outputs a cut-off signal when receiving a first level signal and outputs a turn-on signal when receiving a second level signal; the second switch circuit outputs a holding signal to the target circuit when receiving the cut-off signal, and outputs an over-current protection signal to the target circuit when receiving the conduction signal, wherein the over-current protection signal is used for indicating the target circuit to cut off the power supply loop. The overcurrent detection is carried out on the current through the hardware circuit, so that the overcurrent protection signal can be rapidly output, and the safety of the circuit is protected in time.

Description

Overcurrent detection circuit and electronic equipment

Technical Field

The application relates to the technical field of overcurrent protection, in particular to an overcurrent detection circuit and electronic equipment.

Background

Currently, energy storage devices detect charging current when charging. If the charging current is detected to be overcurrent, overcurrent protection can be started, and the energy storage equipment is prevented from being damaged by the overcurrent. However, the conventional energy storage device detects the charging current by means of the sampling element and software monitoring, so that the time from data acquisition to protection execution is relatively long. If a transient current with a large current appears in the charging process, the overcurrent protection can be started untimely, and components in the circuit are damaged.

SUMMERY OF THE UTILITY MODEL

The main aim at of this application provides an overcurrent detection circuit, aims at carrying out overcurrent detection to the electric current through the hardware circuit, can export the overcurrent protection signal fast, in time protects circuit safety.

In a first aspect, the present application provides an over-current detection circuit, including:

the control circuit is used for outputting a first level signal when the current flowing through the target circuit is smaller than a preset overcurrent value and outputting a second level signal when the current is larger than or equal to the preset overcurrent value;

the first switch circuit is connected with the control circuit, and outputs a cut-off signal when receiving the first level signal and outputs a turn-on signal when receiving the second level signal;

and the second switch circuit is respectively connected with the first switch circuit and the target circuit, outputs a holding signal to the target circuit when receiving the cut-off signal and outputs an over-current protection signal to the target circuit when receiving the turn-on signal, wherein the over-current protection signal is used for indicating the target circuit to cut off a power supply loop.

In one embodiment, the first switch circuit comprises a first switch tube and a first resistor;

the controlled end of the first switching tube is connected with the control circuit to receive the first level signal or the second level signal;

the first end of the first switch tube is grounded, and the second end of the first switch tube is connected with the second switch circuit;

the first end of the first resistor is connected with the controlled end of the first switch tube, and the second end of the first resistor is connected with the first end of the first switch tube.

In one embodiment, the first switch tube is an NMOS tube; the first level signal is a low level, the second level signal is a high level, the controlled end of the first switch tube is a grid electrode of an NMOS tube, the first end of the first switch tube is a source electrode of the NMOS tube, and the second end of the first switch tube is a drain electrode of the NMOS tube; or alternatively

The first switch tube is a PMOS tube, the first level signal is high level, and the second level signal is low level; the controlled end of the first switch tube is a grid electrode of a PMOS tube, the first end of the first switch tube is a drain electrode of the PMOS tube, and the second end of the first switch tube is a source electrode of the PMOS tube.

In one embodiment, the second switching circuit includes a reverse prevention unit, a switching unit, and an output unit;

the first end of the anti-reverse unit is connected with the first switch circuit, and the second end of the anti-reverse unit is connected with the controlled end of the switch unit and the first end of the switch unit;

and the second end of the switch unit is connected with the first end of the output unit, and the second end of the output unit is used for connecting the target circuit.

In one embodiment, the switch unit comprises a second switch tube and a second resistor;

the controlled end of the second switch tube is connected with the second end of the anti-reverse unit; the first end of the second switch tube is connected with a first power supply, and the second end of the second switch tube is connected with the first end of the output unit;

the second resistor is connected between the controlled end of the second switch tube and the first end of the switch unit.

In an embodiment, the second switch tube is a PMOS tube, the controlled end of the second switch tube is a gate of the PMOS tube, the first end of the second switch tube is a source of the PMOS tube, and the second end of the second switch tube is a drain of the PMOS tube.

In one embodiment, the anti-reverse unit comprises a diode and a third resistor; the cathode of the diode is connected with the first switch circuit, the anode of the diode is connected with the first end of the third resistor, and the second end of the third resistor is used as the second end of the anti-reverse unit.

In one embodiment, the output unit includes a fourth resistor and a fifth resistor; a first end of the fourth resistor is connected with a second end of the second switching tube, and a second end of the fourth resistor is used for connecting the target circuit; the first end of the fifth resistor is connected with the second end of the second switch tube, and the second end of the fifth resistor is grounded.

In a second aspect, an embodiment of the present application further provides an electronic device, including a target circuit and the overcurrent detection circuit as in any one of the embodiments, where the overcurrent detection circuit is connected to the target circuit and configured to output an overcurrent protection signal to instruct the target circuit to disconnect a power supply loop when a current flowing through the target circuit is greater than or equal to a preset overcurrent value.

In an embodiment, the target circuit comprises a power supply loop of a power supply device or a power supply loop of a load device, and the power supply loop comprises a switch unit;

the switch unit is connected with the overcurrent detection circuit, and the switch unit is cut off when receiving the overcurrent protection signal so as to cut off the power supply loop.

The application provides an over-current detection circuit and electronic equipment, wherein the over-current detection circuit comprises a control circuit, a first switch circuit and a second switch circuit, wherein the control circuit is used for connecting a target circuit, and the control circuit is used for outputting a first level signal when the current flowing through the target circuit is smaller than a preset over-current value and outputting a second level signal when the current is larger than or equal to the preset over-current value; the first switch circuit is connected with the control circuit, outputs a cut-off signal when receiving a first level signal and outputs a turn-on signal when receiving a second level signal; the second switch circuit is respectively connected with the first switch circuit and the target circuit, outputs a holding signal to the target circuit when receiving a cut-off signal, and outputs an over-current protection signal to the target circuit when receiving a conducting signal, wherein the over-current protection signal is used for indicating the target circuit to cut off a power supply loop. According to the overcurrent protection circuit, the overcurrent detection of the target circuit is realized by adopting a hardware circuit, and the overcurrent protection signal can be rapidly output through the first switch circuit and the second switch circuit, so that the overcurrent protection function is timely started, and the circuit is prevented from being damaged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a circuit schematic diagram of an embodiment of an over-current detection circuit provided in an embodiment of the present application;

fig. 2 is a circuit schematic diagram of another implementation of an over-current detection circuit provided in an embodiment of the present application;

fig. 3 is a circuit schematic diagram of another implementation manner of an over-current detection circuit provided in an embodiment of the present application;

fig. 4 is a circuit schematic diagram of another implementation manner of an over-current detection circuit provided in an embodiment of the present application;

fig. 5 is a circuit schematic diagram of another implementation manner of an over-current detection circuit provided in an embodiment of the present application;

fig. 6 is a circuit schematic diagram of another implementation manner of an overcurrent detection circuit provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

The implementation, functional features and advantages of the object of the present application will be further explained with reference to the embodiments, and with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

Referring to fig. 1, fig. 1 is a circuit schematic diagram of an embodiment of an over-current detection circuit according to the present application. The over-current detection circuit 100 can be applied to a power supply device for supplying power or a load device for consuming power.

For example, the power supply device may include an energy storage device including an electrical energy storage unit, such as one or more batteries. The power supply device may also include a power input device, which may obtain power from an external power source, such as a power grid, a generator, an energy storage device connected to the power supply device, a solar cell, etc., and the power input device is a charger. The load devices may include electronic devices such as refrigerators, air conditioners, washing machines, lawn mowers, and the like.

As shown in fig. 1, the illustrated overcurrent detection circuit 100 includes a control circuit 110, a first switch circuit 120, and a second switch circuit 130.

The control circuit 110 is configured to be connected to the target circuit 10, and the control circuit 110 is configured to output a first level signal when a current flowing through the target circuit 10 is smaller than a preset overcurrent value, and output a second level signal when the current is greater than or equal to the preset overcurrent value.

It should be noted that the current flowing through the target circuit 10 may be a charging current or a discharging current, and the preset overcurrent value may be set according to an actual situation of the target circuit 10, for example, the preset overcurrent value is determined according to a maximum operating current or a rated power of a component in the target circuit 10, which is not specifically limited in this embodiment.

In one embodiment, the over-current detection circuit 100 can be applied to a power supply device, and the target circuit 10 is, for example, a power supply loop of an energy storage device, the power supply loop is a charging loop when the energy storage device is in a charging state, and a current flowing through the target circuit 10 is a charging current. When the energy storage device is in a discharging state, the power supply circuit is a discharging circuit, and the current flowing through the target circuit 10 is a discharging current. In another embodiment, the over-current detection circuit 100 can be applied to a load device, and the target circuit 10 is, for example, a power utilization loop of the load device.

For example, the energy storage device is charged by a charger. In one aspect, the over-current detection circuit may be disposed in the energy storage device, and when the energy storage device is in a charging state, the target circuit 10 may be a charging circuit of the energy storage device, and a current flowing through the target circuit 10 is a charging current received by the charging circuit. On the other hand, the over-current detection circuit may be disposed in the charger, the target circuit 10 may be a power supply circuit of the charger, and the current flowing through the target circuit 10 is the charging current output by the charger.

In an embodiment, as shown in fig. 2, the control circuit 110 includes a control chip U1, and the control chip U1 is, for example, a single chip. The input pin VINI of the control chip U1 is used for connecting the target circuit 10, and the output pin CO of the control chip U1 is connected to the first switch circuit 120. The control chip U1 is configured to output a related level signal according to a current flowing through the target circuit 10, for example, the control chip U1 outputs a first level signal when an input current of the target circuit 10 is less than a preset overcurrent value, and outputs a second level signal when the input current of the target circuit 10 is greater than or equal to the preset overcurrent value.

For example, the input pin VINI of the control chip U1 is connected to the input pin OCC _ SRC of the over-current detection circuit 100, and the input pin OCC _ SRC of the over-current detection circuit 100 is connected to the target circuit 10. Under a normal condition, when the charging current input by the OCC _ SRC terminal is in a normal range, the output pin CO of the control chip U1 outputs a low level, and when the charging current input by the OCC _ SRC terminal exceeds a set overcurrent value, the output pin CO of the control chip U1 outputs a high level.

In one embodiment, as shown in fig. 3, the control circuit 110 further includes a power supply unit 111, and the power supply unit 111 includes a resistor R6, a resistor R7, and a capacitor C1. The VDD pin of the control chip U1 is connected to a first power supply VDD, which is 3.3V, for example, through a resistor R6 and a resistor R7 connected in series. The first end of the capacitor C1 is connected with a VDD pin of the control chip U1, the second end of the capacitor C1 is connected with a VSS pin of the control chip U1, and the second end of the capacitor C1 is also grounded GND. The control chip U1 starts to work after receiving the power supply voltage of the first power supply VDD, the resistor R6 and the resistor R7 are used for limiting the current of the power supply voltage, and the capacitor C1 is used for filtering the power supply voltage.

It should be noted that, as shown in fig. 3, the control circuit 110 further includes a capacitor C2, where the capacitor C2 is a filter capacitor for filtering a current flowing through a target circuit, so that the current input by the input pin VINI of the control chip U1 is more stable.

In one embodiment, as shown in fig. 1 to 3, the first switch circuit 120 is connected to the control circuit 110, and the first switch circuit 120 outputs an off signal when receiving a first level signal and outputs an on signal when receiving a second level signal.

Illustratively, the first switching circuit 120 turns off when receiving the first level signal, and outputs a turn-off signal to the second switching circuit 130. The first switch circuit 120 is turned on upon receiving the second level signal, and outputs a turn-on signal to the second switch circuit 130.

In one embodiment, as shown in fig. 4 and 5, the first switch circuit 120 includes a first switch tube Q1 and a first resistor R1. The controlled end of the first switch tube Q1 is connected to the control circuit 110 to receive the first level signal or the second level signal, the first end of the first switch tube Q1 is grounded, the second end of the first switch tube Q1 is connected to the second switch circuit 130, the first end of the first resistor R1 is connected to the controlled end of the first switch tube Q1, and the second end of the first resistor R1 is connected to the first end of the first switch tube Q1.

The first resistor R1 is a bias resistor of the first switching tube Q1, the first resistor R1 is connected between the controlled end and the first end of the first switching tube Q1, and the resistance of the first resistor R1 is, for example, 1M Ω. In some embodiments, the first switching tube Q1 may further include a body diode.

In an embodiment, as shown in fig. 4, the first switch Q1 is an NMOS transistor, the first level signal is low, and the second level signal is high. The controlled end of the first switch tube Q1 is a grid (G) pole of an NMOS tube, the first end of the first switch tube Q1 is a source (S) pole of the NMOS tube, and the second end of the first switch tube Q1 is a drain (D) pole of the NMOS tube.

For example, the output pin CO of the control chip U1 outputs a low level, at this time, the G electrode of the first switch tube Q1 is at a low level, the first switch tube Q1 is turned off, and the first switch circuit 120 outputs a turn-off signal. When the charging current input at the OCC _ SRC end exceeds the set overcurrent value, the output pin CO of the control chip U1 outputs a high level, at this time, the G of the first switch tube Q1 is at a high level, the first switch tube Q1 is turned on, and the first switch circuit 120 outputs a turn-on signal.

In one embodiment, as shown in fig. 5, the first switch Q1 is a PMOS transistor, the first level signal is high, and the second level signal is low. The controlled end of the first switch tube Q1 is a gate (G) pole of a PMOS tube, the first end of the first switch tube Q1 is a drain (D) pole of the PMOS tube, and the second end of the first switch tube Q1 is a source (S) pole of the PMOS tube.

Illustratively, the output pin CO of the control chip U1 outputs a high level, at this time, the terminal G of the first switch Q1 is at a high level, the first switch Q1 is turned off, and the first switch circuit 120 outputs a turn-off signal. When the current input at the OCC _ SRC end exceeds the set overcurrent value, the output pin CO of the control chip U1 outputs a low level, at this time, the G of the first switch tube Q1 is at a low level, the first switch tube Q1 is turned on, and the first switch circuit 120 outputs a turn-on signal.

In one embodiment, as shown in fig. 1 to 5, the second switch circuit 130 is connected to the first switch circuit 120 and the target circuit 10, respectively, and the second switch circuit 130 outputs a hold signal to the target circuit 10 when receiving a turn-off signal and outputs an over-current protection signal to the target circuit 10 when receiving a turn-on signal. The hold signal is used to instruct the target circuit 10 to hold the power supply loop, and the over-current protection signal is used to instruct the target circuit 10 to disconnect the power supply loop.

Illustratively, the second switching circuit 130 is turned off upon receiving the off signal, and outputs a hold signal to the target circuit 10. The second switch circuit 130 is turned on upon receiving the on signal, and outputs an overcurrent protection signal to the target circuit 10. The power supply circuit may be a circuit that outputs current, such as a discharging circuit, or a circuit that receives current, such as a charging circuit or a power utilization circuit. The hold signal is high and the over-current protection signal is low. Alternatively, the hold signal is low and the over-current protection signal is high.

In one embodiment, as shown in fig. 6, the second switching circuit 130 includes a reverse prevention unit 131, a switching unit 132, and an output unit 133. Wherein, the first end of the anti-reverse unit 131 is connected to the first switch circuit 120, and the second end of the anti-reverse unit 131 is connected to the controlled end of the switch unit 132 and the first end of the switch unit 132; a second terminal of the switching unit 132 is connected to a first terminal of the output unit 133, and a second terminal of the output unit 133 is used to connect the target circuit 10.

In one embodiment, as shown in fig. 6, the anti-reverse unit 131 includes a diode D1 and a third resistor R3. The cathode of the diode D1 is connected to the first switch circuit 120, the anode of the diode D1 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 serves as the second end of the anti-reverse unit 131. It should be noted that reverse connection prevention protection between the first switch circuit 120 and the second switch circuit 130 is implemented through the diode D1 and the third resistor R3, so as to prevent the current from flowing backwards.

In one embodiment, as shown in fig. 6, the switching unit 132 includes a second switching tube Q2 and a second resistor R2. The controlled end of the second switch tube Q2 is connected with the second end of the anti-reverse unit 131; a first end of the second switching tube Q2 is connected to the first power supply VDD, and a second end of the second switching tube Q2 is connected to a first end of the output unit 133; the second resistor R2 is connected between the controlled terminal of the second switch Q2 and the first terminal of the switch unit 132.

The second resistor R2 is a bias resistor of the second switch Q2, the second resistor R2 is connected between the controlled end and the first end of the second switch Q2, the voltage of the first power supply VDD is, for example, 3.3V, and the resistance of the second resistor R2 is, for example, 1M Ω. In some embodiments, the second switching tube Q2 may further include a body diode.

In an embodiment, as shown in fig. 6, the second switch Q2 is a PMOS transistor, the controlled terminal of the second switch Q2 is a gate (G) pole of the PMOS transistor, the first terminal of the second switch Q2 is a source (S) pole of the PMOS transistor, and the second terminal of the second switch Q2 is a drain (D) pole of the PMOS transistor.

For example, the output pin CO of the control chip U1 outputs a low level, at this time, the G electrode of the first switch tube Q1 is at a low level, and the first switch tube Q1 is turned off. When the first switch Q1 is turned off, the gate voltage of the second switch Q2 is high (the first power supply VDD is divided to the G-pole by the second resistor R2), and thus the second switch Q2 is turned off. At this time, the output terminal iintoc of the over-current detection circuit 100 passes through the fourth resistor R4 and the fifth resistor R5 and then is grounded, that is, the output of the output terminal iintoc is a low level, which is a hold signal.

For example, the output pin CO of the control chip U1 outputs a high level, and at this time, the G electrode of the first switch tube Q1 is at a high level, and the first switch tube Q1 is turned on. When the first switching tube Q1 is turned on, the G pole of the second switching tube Q2 is grounded through the diode D1 and the third resistor R3, that is, the G pole of the second switching tube Q2 is at a low level, so that the second switching tube Q2 is turned on. At this time, the output terminal iintoc of the over-current detection circuit 100 is connected to the first power supply VDD through the second resistor R2, that is, the output of the output terminal iintoc is a high level, which is an over-current protection signal.

It should be noted that the above embodiments can be set according to actual practice. If the current input at the OCC _ SRC terminal is normal (the current is smaller than the preset overcurrent value), the output of the control chip U1 is a high level, and the output of the output terminal iintoc is a high level; when the current input at the OCC _ SRC terminal is overcurrent (the current is greater than or equal to the preset overcurrent value), the output of the control chip U1 is low level, and the output of the output terminal iintoc is also low level. Through the technical scheme provided by the application, the overcurrent detection of the current flowing through the target circuit 10 can be realized through a hardware circuit, the current can be quickly responded when the overcurrent is determined, and the relevant overcurrent protection signal is output so as to execute the overcurrent protection operation and avoid the target circuit 10 from overcurrent damage.

In one embodiment, as shown in fig. 6, the output unit 133 includes a fourth resistor R4 and a fifth resistor R5. A first end of the fourth resistor R4 is connected to a second end of the second switch Q2, and a second end of the fourth resistor R4 is used for connecting the target circuit 10; a first end of the fifth resistor R5 is connected to the second end of the second switch Q2, and a second end of the fifth resistor R5 is grounded. The second end of the fourth resistor R4 can be used as the output terminal iintoc of the over-current detection circuit 100, and outputs a holding signal or an over-current protection signal to the target circuit 10 through the fourth resistor R4 and the fifth resistor R5.

In some embodiments, the output terminal iintoc of the over-current detection circuit provided in the present disclosure may be directly connected to a charging switch of the target circuit 10, where the charging switch is kept on when receiving a holding signal output by the output terminal iintoc, and is disconnected when the output terminal iintoc outputs an over-current protection signal, so as to disconnect a power supply loop of the target circuit 10. It should be noted that the target circuit 10 is, for example, a charging circuit in the energy storage device, and the charging switch may be turned on at a high level or turned on at a low level according to the selection of the switch.

In some embodiments, the output terminal iintoc of the over-current detection circuit 100 provided in the present disclosure may be connected to the target circuit 10 through a controller in the energy storage device or the load device, where the controller performs corresponding operations according to the hold signal or the over-current protection signal output by the over-current detection circuit 100, that is, when the hold signal output by the output terminal iintoc is received, the power supply circuit of the target circuit 10 is kept on, and when the over-current protection signal output by the output terminal iintoc is received, the power supply circuit of the target circuit 10 is controlled to be off.

The over-current detection circuit 500 according to the above embodiment includes a control circuit 110, a first switch circuit 120, and a second switch circuit 130, where the control circuit 110 is configured to be connected to the target circuit 10, and the control circuit 110 is configured to output a first level signal when a current flowing through the target circuit 10 is smaller than a preset over-current value, and output a second level signal when the current is greater than or equal to the preset over-current value; the first switch circuit 120 is connected to the control circuit 110, and the first switch circuit 120 outputs a turn-off signal when receiving the first level signal and outputs a turn-on signal when receiving the second level signal; the second switch circuit 130 is connected to the first switch circuit 120 and the target circuit 10, respectively, and the second switch circuit 130 outputs a hold signal to the target circuit 10 when receiving a turn-off signal and outputs an over-current protection signal to the target circuit 10 when receiving a turn-on signal, where the over-current protection signal is used to instruct the target circuit 10 to turn off the power supply loop. According to the overcurrent protection circuit, the overcurrent detection of the target circuit 10 is realized by adopting a hardware circuit, and the overcurrent protection signal can be rapidly output through the first switch circuit 120 and the second switch circuit 130, so that the overcurrent protection function is timely started, and the circuit is prevented from being damaged.

It should be noted that, in the present application, the control circuit 110 outputs the first level signal or the second level signal according to actual settings, and when the control circuit 110 has a program abnormality or a fault, it continuously outputs the second level signal, so as to achieve the purpose of further protecting the target circuit when the control circuit 110 cannot perform control.

Referring to fig. 7, fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.

As shown in fig. 7, the electronic device 300 includes:

a target circuit 310;

in the over-current detection circuit 320 according to the above embodiment, the over-current detection circuit 320 is connected to the target circuit 310, and the over-current detection circuit 320 is configured to output an over-current protection signal when a current flowing through the target circuit 310 is greater than or equal to a preset over-current value, so as to instruct the target circuit 310 to disconnect a power supply loop.

In an embodiment, the target circuit 10 comprises a supply loop of a power supply device or a supply loop of a load device, the supply loop comprising a switching unit. The switch unit is connected to the over-current detection circuit 320, and is cut off when receiving the over-current protection signal output by the over-current detection circuit 320, so as to disconnect the power supply loop. The switch unit is turned on when receiving the hold signal output by the over-current detection circuit 320, so as to keep the power supply loop continuously flowing through the current.

The switch unit comprises a switch device, wherein the switch device is turned off when receiving the overcurrent protection signal and is kept turned on when receiving the holding signal. In some embodiments, the switch unit may further include a controller, and the controller controls the switch device to be turned off or turned on, which is not described herein again.

The electronic device 300 according to the above embodiment includes the target circuit 310 and the over-current detection circuit 320, where the over-current detection circuit 320 may be the over-current detection circuit 100 according to the above embodiment.

In an embodiment, the over-current detection circuit 320 may include the control circuit 110, the first switch circuit 120, and the second switch circuit 130 described in the above embodiments, wherein the control circuit 110 is connected to the target circuit 10, and the control circuit 110 is configured to output a first level signal when a current flowing through the target circuit 10 is smaller than a preset over-current value, and output a second level signal when the current is greater than or equal to the preset over-current value; the first switch circuit 120 is connected to the control circuit 110, and the first switch circuit 120 outputs a turn-off signal when receiving the first level signal and outputs a turn-on signal when receiving the second level signal; the second switch circuit 130 is connected to the first switch circuit 120 and the target circuit 10, respectively, and the second switch circuit 130 outputs a hold signal to the target circuit 10 when receiving the turn-off signal and outputs an over-current protection signal to the target circuit 10 when receiving the turn-on signal, where the over-current protection signal is used to instruct the target circuit 10 to turn off the power supply circuit. The overcurrent detection of the target circuit 10 is realized by adopting a hardware circuit, and the overcurrent protection signal can be rapidly output through the first switch circuit 120 and the second switch circuit 130, so that the overcurrent protection function is started in time, and the target circuit 10 is prevented from being damaged.

In the description of the present application, it is to be noted that the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless otherwise explicitly stated or limited. Either mechanically or electrically. They may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation of the first and second features not being in direct contact, but being in contact with another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The above disclosure provides many different embodiments or examples for implementing different structures of the application. The components and arrangements of specific examples are described above to simplify the present disclosure. Of course, they are merely examples and are not intended to limit the present application. Further, the present application may repeat reference numerals and/or reference letters in the various examples for simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or arrangements discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

In the description of the present specification, reference to the description of "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above embodiments are only preferred embodiments of the present application, and the protection scope of the present application is not limited thereto, and any insubstantial changes and substitutions made by those skilled in the art based on the present application are intended to be covered by the present application.

Claims (10)

1. An over-current detection circuit, comprising:

the control circuit is used for outputting a first level signal when the current flowing through the target circuit is smaller than a preset overcurrent value and outputting a second level signal when the current is larger than or equal to the preset overcurrent value;

the first switch circuit is connected with the control circuit, and outputs a cut-off signal when receiving the first level signal and outputs a turn-on signal when receiving the second level signal;

and the second switch circuit is respectively connected with the first switch circuit and the target circuit, outputs a holding signal to the target circuit when receiving the cut-off signal, and outputs an over-current protection signal to the target circuit when receiving the conducting signal, wherein the over-current protection signal is used for indicating the target circuit to cut off a power supply loop.

2. The over-current detection circuit of claim 1, wherein the first switching circuit comprises a first switching tube and a first resistor;

the controlled end of the first switching tube is connected with the control circuit to receive the first level signal or the second level signal;

the first end of the first switch tube is grounded, and the second end of the first switch tube is connected with the second switch circuit;

the first end of the first resistor is connected with the controlled end of the first switch tube, and the second end of the first resistor is connected with the first end of the first switch tube.

3. The over-current detection circuit according to claim 2, wherein the first switch transistor is an NMOS transistor, the first level signal is a low level, and the second level signal is a high level; the controlled end of the first switch tube is a grid electrode of an NMOS tube, the first end of the first switch tube is a source electrode of the NMOS tube, and the second end of the first switch tube is a drain electrode of the NMOS tube; or

The first switch tube is a PMOS tube, the first level signal is a high level, and the second level signal is a low level; the controlled end of the first switch tube is a grid electrode of a PMOS tube, the first end of the first switch tube is a drain electrode of the PMOS tube, and the second end of the first switch tube is a source electrode of the PMOS tube.

4. The overcurrent detection circuit according to claim 1, wherein the second switch circuit comprises a reverse prevention unit, a switch unit, and an output unit;

the first end of the anti-reverse unit is connected with the first switch circuit, and the second end of the anti-reverse unit is connected with the controlled end of the switch unit and the first end of the switch unit;

and the second end of the switch unit is connected with the first end of the output unit, and the second end of the output unit is used for connecting the target circuit.

5. The over-current detection circuit according to claim 4, wherein the switching unit comprises a second switching tube and a second resistor;

the controlled end of the second switch tube is connected with the second end of the anti-reverse unit; the first end of the second switching tube is connected with a first power supply, and the second end of the second switching tube is connected with the first end of the output unit;

the second resistor is connected between the controlled end of the second switch tube and the first end of the switch unit.

6. The over-current detection circuit according to claim 5, wherein the second switch tube is a PMOS tube, the controlled end of the second switch tube is a gate of the PMOS tube, the first end of the second switch tube is a source of the PMOS tube, and the second end of the second switch tube is a drain of the PMOS tube.

7. The overcurrent detection circuit of claim 5, wherein the anti-reverse unit comprises a diode and a third resistor; the cathode of the diode is connected with the first switch circuit, the anode of the diode is connected with the first end of the third resistor, and the second end of the third resistor is used as the second end of the anti-reverse unit.

8. The overcurrent detection circuit of claim 5, wherein the output unit comprises a fourth resistor and a fifth resistor; a first end of the fourth resistor is connected with a second end of the second switching tube, and a second end of the fourth resistor is used for connecting the target circuit; the first end of the fifth resistor is connected with the second end of the second switch tube, and the second end of the fifth resistor is grounded.

9. An electronic device, comprising

A target circuit; and

the over-current detection circuit as claimed in any one of claims 1 to 8, wherein the over-current detection circuit is connected to the target circuit and is configured to output an over-current protection signal when the current flowing through the target circuit is greater than or equal to a preset over-current value, so as to instruct the target circuit to disconnect a power supply loop.

10. The electronic device of claim 9, wherein the target circuit comprises a power supply loop of a power supply device or a power supply loop of a load device, the power supply loop comprising a switching unit;

the switch unit is connected with the overcurrent detection circuit, and the switch unit is cut off when receiving the overcurrent protection signal so as to cut off the power supply loop.

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