Anti-reverse-flow circuit and electronic equipment

Abstract

The utility model provides an anti-reversion circuit and electronic equipment, the anti-reversion circuit comprises a positive wire, a negative wire, a diode, a first switch, an energy storage unit and a control circuit, the positive wire is connected with a power supply positive electrode and a load positive electrode; the cathode line is connected with the power supply cathode and the load cathode; the anode of the diode is connected with the anode line, and the cathode is connected with the cathode line; the first switch is arranged on a conductive path of the positive wire or the negative wire; the control circuit is connected with the anode and the cathode of the diode and the control end of the first switch, and the control circuit is configured to control the first switch to be switched off when the anode voltage of the diode is smaller than the cathode voltage. The diode is arranged between the positive wire and the negative wire, whether backward voltage appears in the circuit can be determined by detecting voltage drop at two ends of the diode, and then the first switch is controlled to be switched off or switched on; as the conduction voltage drop of the diode is easier to detect than the conduction voltage drop of the MOS tube, the complexity of the control circuit can be reduced, and the cost of the anti-reverse circuit is further reduced.

Description

Technical Field

[0001] The disclosed embodiments of the present application relate to the field of electronic technology, and more specifically, to an anti-reverse circuit and an electronic device. Background Art

[0002] The anti-reverse circuit can prevent the current in the circuit from flowing in the reverse direction, thereby protecting the components in the circuit.

[0003] In some simple circuits, diodes can be used to achieve the above protection effect. However, due to the large conduction voltage drop of the diode, the power consumption is high and the heat generation is serious. Therefore, MOS tubes are usually used and the conduction voltage drop of the MOS tube is monitored by an integrated chip to control the conduction or disconnection of the MOS tube, thereby simulating the unidirectional conduction effect of the diode. However, the conduction voltage drop of the MOS tube is very small, and a high-rate low-noise differential amplification is required to achieve it. The circuit is complex and difficult to achieve with a discrete circuit. It is generally implemented by a dedicated integrated circuit, which is costly.

[0004] Therefore, how to reduce the cost of anti-reverse circuits becomes an urgent problem to be solved. Utility Model Content

[0005] According to an embodiment of the present application, the present application proposes an anti-reverse circuit and an electronic device to reduce the cost of the anti-reverse circuit.

[0006] According to one aspect of the present application, an exemplary anti-reverse circuit is disclosed, including a positive line, a negative line, a diode, a first switch, an energy storage unit and a control circuit, wherein the positive line is connected to the positive electrode of a power source and the positive electrode of a load; the negative line is connected to the negative electrode of a power source and the negative electrode of a load; the anode of the diode is connected to the positive line, and the cathode of the diode is connected to the negative line; one end of the energy storage unit is connected to the cathode of the diode, and the other end is connected to the negative line; the first switch is arranged on a conductive path of the positive line or the negative line; the control circuit is connected to the anode and cathode of the diode, and the control end of the first switch, and the control circuit is configured to control the first switch to be disconnected when the anode voltage of the diode is less than the cathode voltage.

[0007] In the above scheme, a diode is set between the positive line and the negative line. By detecting the voltage drop across the diode, it is possible to determine whether a reverse voltage appears in the circuit, thereby controlling the first switch to be disconnected or turned on. Since the diode conduction voltage drop is easier to detect than the MOS tube conduction voltage drop, it is possible to reduce the complexity of the control circuit, thereby reducing the cost of the anti-reverse circuit.

[0008] Wherein, the control circuit includes a comparison unit and a switching unit; the comparison unit is connected to the anode and cathode of the diode to compare the voltage magnitudes of the anode and cathode of the diode; the switching unit is connected to the comparison unit and the control end of the first switch; wherein the comparison unit is configured to selectively output a first switching signal to the switching unit based on the voltage magnitude relationship between the cathode and anode of the diode; the switching unit is configured to control the first switch to be disconnected when receiving the first switching signal.

[0009] In the above scheme, the comparison unit compares the voltages of the anode and cathode of the diode, and the switching unit controls the first switch to be disconnected. Since the voltage drop across the diode is easier to detect, the complexity of the comparison unit can be reduced, thereby reducing the cost of the anti-reverse circuit.

[0010] The comparison unit comprises a second switch, a first end of which is connected to the cathode of the diode, a second end of which is connected to the anode of the diode, and a third end of which is connected to the switching unit.

[0011] In the above solution, by comparing the voltage between the anode and cathode of the diode through the second switch, the complexity of the comparison unit can be further reduced, and the cost of the anti-reverse circuit can be further reduced.

[0012] Wherein, the switching unit includes a third switch, a first end of which is connected to the positive electrode of the load or the negative electrode of the load, a second end of which is connected to the control end of the first switch, and the control end is connected to the comparison unit; the third switch is configured to be conductive between its first end and the second end when receiving the first switching signal, and control the first switch to be disconnected.

[0013] In the above solution, the third switch is used to control the first switch to be disconnected, which can reduce the complexity of the switching unit and further reduce the cost of the anti-reverse circuit.

[0014] The first switch is a MOSFET, a drain of the first switch is connected to a power supply, a source is connected to a load and the control circuit, and a gate is connected to the control circuit.

[0015] The first switch is a P-type MOSFET; the drain of the first switch is connected to the positive electrode of the power supply, the source is connected to the positive electrode of the load and the control circuit, and the gate is connected to the negative electrode line and the control circuit.

[0016] The first switch is an N-type MOSFET; the drain of the first switch is connected to the negative electrode of the power supply, the source is connected to the negative electrode of the load and the control circuit, and the gate is connected to the positive line and the control circuit.

[0017] The above solution uses MOSFET as the circuit conduction path. Since the MOSFET conduction voltage is low, the circuit power consumption and heat generation can be reduced.

[0018] The energy storage unit is configured to output a voltage to the diode when the power supply voltage drops.

[0019] In the above scheme, the energy storage unit outputs voltage to the diode when the power supply voltage drops, so that both ends of the diode are subjected to reverse voltage when the power supply voltage drops, that is, the analog circuit is connected to the reverse voltage, so that the anti-reverse circuit reacts when the power supply voltage drops, thereby further improving the anti-reverse protection effect.

[0020] The energy storage unit includes a first capacitor and a first resistor, one end of the first capacitor is connected to the cathode of the diode, and the other end is connected to the negative line; the first resistor is connected in parallel with the first capacitor.

[0021] The above solution can reduce the structural complexity of the energy storage unit through the first capacitor, thereby reducing the cost of the anti-reverse circuit; the first resistor allows the first capacitor to discharge slowly.

[0022] According to a second aspect of the present application, an electronic device is disclosed, comprising any one of the anti-reverse circuits of the first aspect.

[0023] In the above scheme, a diode is set between the positive line and the negative line. By detecting the voltage drop across the diode, it is possible to determine whether a reverse voltage appears in the circuit, thereby controlling the first switch to be disconnected or turned on. Since the diode conduction voltage drop is easier to detect than the MOS tube conduction voltage drop, it is possible to reduce the complexity of the control circuit, thereby reducing the cost of the anti-reverse circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present application will be further described below in conjunction with the accompanying drawings and implementation methods, in which:

[0025] Figure 1 It is a schematic diagram of the framework of an embodiment of the anti-reverse circuit of the present application;

[0026] Figure 2 is a schematic diagram of a framework of another embodiment of the anti-reverse circuit of the present application;

[0027] Figure 3 It is a schematic diagram of a framework of another embodiment of the anti-reverse circuit of the present application;

[0028] Figure 4 It is a schematic diagram of a framework of another embodiment of the anti-reverse circuit of the present application;

[0029] Figure 5 A schematic diagram of a framework of another embodiment of the anti-reverse circuit of the present application;

[0030] Figure 6A schematic diagram of a framework of another embodiment of the anti-reverse circuit of the present application;

[0031] Figure 7 is a schematic diagram of the circuit structure of an embodiment of the anti-reverse circuit of the present application;

[0032] Figure 8 is a circuit structure schematic diagram of another embodiment of the anti-reverse circuit of the present application;

[0033] Fig. 9 It is a schematic diagram of the framework of an embodiment of the electronic device of the present application. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution of the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0035] The present application discloses an anti-reverse circuit. Figure 1 , Figure 1 It is a framework schematic diagram of an embodiment of the anti-reverse circuit of the present application; specifically, the anti-reverse circuit 100 includes a positive line, a negative line, a diode, a first switch 110 and a control circuit 120, the positive line is connected to the positive pole of the power supply and the positive pole of the load; the negative line is connected to the negative pole of the power supply and the negative pole of the load; the anode of the diode is connected to the positive line, and the cathode of the diode is connected to the negative line; one end of the energy storage unit 130 is connected to the cathode of the diode, and the other end is connected to the negative line; the first switch 110 is set on the conductive path of the positive line or the negative line; the control circuit 120 is connected to the anode and cathode of the diode, and the control end 110a of the first switch 110, and the control circuit 120 is configured to control the first switch 110 to disconnect when the anode voltage of the diode is less than the cathode voltage.

[0036] like Figure 1 As shown, the control circuit 120 can be used to detect the voltage drop across the diode. When the power supply outputs a forward voltage, that is, the positive voltage of the power supply is greater than the negative voltage of the power supply, the anode voltage of the diode is greater than the cathode voltage. The control circuit 120 controls the first switch 110 to disconnect to cut off the reverse current and prevent the reverse current from damaging other components in the circuit.

[0037] In the above scheme, a diode is set between the positive line and the negative line. By detecting the voltage drop across the diode, it is possible to determine whether a reverse voltage appears in the circuit, thereby controlling the first switch 110 to be disconnected or turned on. Since the diode conduction voltage drop is easier to detect than the MOS tube conduction voltage drop, the complexity of the control circuit 120 can be reduced, thereby reducing the cost of the anti-reverse circuit 100.

[0038] In some embodiments, please refer to Figure 2 , Figure 2It is a framework diagram of another embodiment of the anti-reverse circuit of the present application; the control circuit 120 includes a comparison unit 121 and a switching unit 122; the comparison unit 121 is connected to the anode and cathode of the diode, and compares the voltage magnitudes of the anode and cathode of the diode; the switching unit 122 is connected to the comparison unit 121 and the control end 110a of the first switch 110; wherein the comparison unit 121 is configured to selectively output a first switching signal to the switching unit 122 based on the voltage magnitude relationship between the cathode and anode of the diode; the switching unit 122 is configured to control the first switch 110 to disconnect when receiving the first switching signal.

[0039] In the above scheme, the comparison unit 121 compares the voltages of the anode and cathode of the diode, and the switching unit 122 controls the first switch 110 to be disconnected. Since the voltage drop across the diode is easier to detect, the complexity of the comparison unit 121 can be reduced, thereby reducing the cost of the anti-reverse circuit 100.

[0040] In some embodiments, the comparison unit 121 may include a voltage comparator. By comparing the voltage drop across the diode through the voltage comparator, it is possible to determine whether there is a reverse voltage across the diode.

[0041] In some embodiments, the comparison unit 121 may include a second switch, a first terminal of which is connected to the cathode of the diode, a second terminal of which is connected to the anode of the diode, and a third terminal of which is connected to the switching unit 122 .

[0042] In the above solution, by comparing the voltage between the anode and the cathode of the diode through the second switch, the complexity of the comparison unit 121 can be further reduced, and the cost of the anti-reverse circuit 100 can be further reduced.

[0043] In some embodiments, the second switch may be a transistor. Figure 3 , Figure 3 Schematic diagram of the framework of another embodiment of the anti-reverse circuit of the present application; Figure 3 As shown, the second switch can be an NPN transistor, whose emitter is connected to the anode of the diode, the base is connected to the cathode of the diode, and the collector is connected to the switching unit 122; the diode conduction voltage drop is 0.7V, which can be used to drive the transistor; when the positive voltage of the power supply is higher than the negative voltage of the power supply, the emitter voltage of the transistor Q1 is higher than the collector voltage, and the transistor Q1 is turned off; when the positive voltage of the power supply is higher than the negative voltage of the power supply, the emitter voltage of the transistor Q1 is lower than the collector voltage, and the transistor Q1 is turned on; therefore, the transistor Q1 can control its on or off state according to whether the power supply outputs a reverse voltage, and output different level signals to the switching unit 122, indicating that the power supply outputs a forward voltage and a reverse voltage, respectively, so that the switching unit 122 controls the first switch 110 to be turned on or off according to different level signals.

[0044] In other embodiments, the transistor Q1 may also have its base connected to the anode of the diode, its emitter connected to the cathode of the diode, and its collector connected to the switching unit 122; the second switch may also be a MOSFET, in which case a resistor may be connected in series with the diode to increase the gate-source voltage of the MOSFET to reach the threshold voltage of the driving MOSFET. The second switch may also adopt other implementations not specified in this application.

[0045] It should be noted that the first switching signal can be a high-level signal or a low-level signal, and can be configured according to the actual selection of the second switch and the actual circuit structure, which is not limited in this application.

[0046] In some embodiments, the switching unit 122 may include a third switch, a first end of which is connected to the positive electrode of the load or the negative electrode of the load, and a second end of which is connected to the control end 110a of the first switch 110, and the control end 110a is connected to the comparison unit 121; the third switch is configured to be conductive between its first end and the second end when receiving the first switching signal, and control the first switch 110 to be disconnected.

[0047] In the above solution, the third switch is used to control the first switch 110 to be disconnected, which can reduce the complexity of the switching unit 122 and further reduce the cost of the anti-reverse circuit 100.

[0048] Please refer to Figure 4 , Figure 4 Schematic diagram of the framework of another embodiment of the anti-reverse circuit of the present application; Figure 4 As shown, the third switch can be a PNP transistor, whose base is connected to the comparison unit 121, the emitter is connected to the positive line, and the collector is connected to the control terminal 110a of the first switch 110; therefore, the transistor Q2 can output a high level or low level signal to the control terminal 110a of the first switch 110 through its on or off state to control the on or off of the first switch 110.

[0049] The third switch may also be a MOSFET, etc., which is not limited in this application.

[0050] In some embodiments, the first switch 110 may be a MOSFET, the drain of the first switch 110 is connected to a power source, the source is connected to a load and the control circuit 120, and the gate is connected to the control circuit 120. By using MOSFET as a circuit conduction path, since the MOSFET conduction voltage drop is low, the circuit power consumption can be reduced and heat generation can be reduced.

[0051] In some embodiments, please refer to Figure 5 , Figure 5This is a schematic diagram of the framework of another embodiment of the anti-reverse circuit of the present application; specifically, the first switch 110 can be a P-type MOSFET; the drain of the first switch 110 is connected to the positive pole of the power supply, the source is connected to the positive pole of the load and the control circuit 120, and the gate can be connected to the negative line through a resistor and connected to the control circuit 120.

[0052] In some embodiments, please refer to Figure 6 , Figure 6 This is a schematic diagram of the framework of another embodiment of the anti-reverse circuit of the present application; specifically, the first switch 110 can be an N-type MOSFET; the drain of the first switch 110 is connected to the negative electrode of the power supply, the source is connected to the negative electrode of the load and the control circuit 120, and the gate can be connected to the positive line through a resistor and connected to the control circuit 120.

[0053] In some embodiments, the energy storage unit 130 is configured to output a voltage to the diode when the power supply voltage drops.

[0054] In some embodiments, Figure 3 to Figure 6 As shown, the energy storage unit 130 may include a first capacitor C1 and a first resistor R1, one end of the first capacitor C1 is connected to the cathode of the diode, and the other end is connected to the negative line. The first resistor R1 is connected in parallel with the first capacitor C1. Specifically, the energy storage unit 130 may include a plurality of first capacitors, and the specific number of the first capacitors of the energy storage unit 130 is not limited in this application.

[0055] The above solution can reduce the structural complexity of the energy storage unit 130 through the first capacitor, thereby reducing the cost of the anti-reverse circuit 100.

[0056] Please refer to Figure 7 , Figure 7 Schematic diagram of the circuit structure of an embodiment of the anti-reverse circuit of the present application; Figure 7As shown, the drain of the P-type MOSFET tube M1 is connected to the positive electrode of the power supply Vin, the source is connected to the positive electrode of the load Vout, and the gate is grounded GND through a resistor R4; the anode of the diode D1 is connected to the positive electrode of the power supply Vin, and the cathode is grounded through a resistor R1 and a capacitor C1; the emitter of the NPN transistor Q1 is connected to the diode D1, the base is connected to the cathode of the diode D1 through a resistor R3, and the collector is connected to the base of the PNP transistor Q2 through a resistor R2, and the emitter and collector of the transistor Q2 are respectively connected to the source and gate of the MOSFET and the two ends of the capacitor C2. Therefore, when the power supply outputs a forward voltage, that is, the voltage of the positive electrode Vin of the power supply is greater than the ground voltage, the anode voltage of the diode D1 is greater than the cathode voltage, that is, the emitter voltage of the NPN transistor is greater than the collector voltage, so the transistor Q1 is turned off, and the transistor Q2 is turned off at the same time. When the absolute value of the gate-source voltage of the MOSFET is greater than the threshold voltage, the MOSFET can be turned on; and when the power supply outputs a reverse voltage, that is, the voltage of the positive electrode Vin of the power supply is less than the ground voltage or the voltage of the positive electrode Vin of the power supply drops instantly, due to the energy storage effect of the capacitor C1, at this time, the anode voltage of the diode D1 is less than the cathode voltage, that is, the emitter voltage of the NPN transistor is less than the collector voltage, at this time, the transistor Q1 is turned on, and the transistor Q2 is turned on at the same time, so the gate-source voltage of the MOSFET is pulled down due to the conduction of the transistor Q2, and the MOS tube M1 is turned off.

[0057] Please refer to Figure 8 , Figure 8 FIG. 1 is a schematic diagram of the circuit structure of another embodiment of the anti-reverse circuit of the present application; Figure 8As shown, the drain of the N-type MOSFET tube M1 is connected to the negative electrode GND of the power supply, the source is connected to the negative electrode GND1 of the load, and the gate is connected to the positive electrode Vin of the power supply through the resistor R4; the anode of the diode D1 is connected to the positive electrode Vin of the power supply through the resistor R1 and the capacitor C1, and the cathode is connected to the negative electrode GND of the power supply; the emitter of the PNP transistor Q1 is connected to the diode D1, the base is connected to the anode of the diode D1 through the resistor R3, and the collector is connected to the base of the NPN transistor Q2 through the resistor R2, and the emitter and collector of the transistor Q2 are connected to the source and gate of the MOSFET and the two ends of the capacitor C2. Therefore, when the power supply outputs a forward voltage, that is, the voltage of the positive electrode Vin of the power supply is greater than the ground voltage, the anode voltage of the diode D1 is greater than the cathode voltage, that is, the emitter voltage of the PNP transistor Q1 is less than the collector voltage, so the transistor Q1 is turned off, and the transistor Q2 is turned off at the same time. When the absolute value of the gate-source voltage of the MOSFET is greater than the threshold voltage, the MOSFET can be turned on; and when the power supply outputs a reverse voltage, that is, the voltage of the positive electrode Vin of the power supply is less than the ground voltage or the voltage of the positive electrode Vin of the power supply drops instantly, due to the energy storage effect of the capacitor C1, the anode voltage of the diode D1 is less than the cathode voltage. At this time, the transistor Q1 is turned on, and the transistor Q2 is turned on at the same time. Therefore, the gate-source voltage of the MOSFET is pulled down due to the conduction of the transistor Q2, and the MOS tube M1 is turned off.

[0058] The above scheme has a simple circuit structure, and the circuit is turned on and off by MOSFET, and the action time can be less than 1 microsecond, thereby improving the effect of blocking reverse current. In addition, since the MOSFET has a small on-state voltage drop, it can reduce heat generation and power consumption.

[0059] The second aspect of the present application provides an electronic device, please refer to Fig. 9 , Fig. 9 It is a schematic diagram of a framework of an embodiment of an electronic device of the present application; specifically, the electronic device 200 includes the anti-reverse circuit 100 in any one embodiment of the first aspect described above.

[0060] It should be noted that the electronic device may be a power output device, or may be a device with a camera function such as a handheld camera, a fixed camera, etc., such as a surveillance camera.

[0061] It is easy for a person skilled in the art to know that many modifications and changes can be made to the device and method while maintaining the teaching content of the present application. Therefore, the above disclosure should be considered as limited only by the scope of the appended claims.

Claims

1. An anti-reverse circuit, characterized in that: The anti-reverse circuit comprises: Positive wire, connecting the positive pole of the power supply and the positive pole of the load; Negative wire, connecting the negative pole of the power supply and the negative pole of the load; a diode, wherein an anode of the diode is connected to the positive line, and a cathode of the diode is connected to the negative line; An energy storage unit, one end of which is connected to the cathode of the diode and the other end of which is connected to the negative electrode line; A first switch is disposed on a conductive path of the positive line or the negative line; The control circuit is connected to the anode and cathode of the diode and the control end of the first switch, and the control circuit is configured to control the first switch to be disconnected when the anode voltage of the diode is less than the cathode voltage.

2. The anti-reverse circuit according to claim 1, characterized in that: The control circuit comprises: A comparison unit, connected to the anode and cathode of the diode, and comparing the voltages of the anode and cathode of the diode; a switching unit connected to the comparison unit and a control end of the first switch; The comparison unit is configured to selectively output a first switching signal to the switching unit based on a voltage magnitude relationship between a cathode and an anode of the diode; and the switching unit is configured to control the first switch to be disconnected when receiving the first switching signal.

3. The anti-reverse circuit according to claim 2, characterized in that: The comparison unit comprises: The second switch has a first end connected to the cathode of the diode, a second end connected to the anode of the diode, and a third end connected to the switching unit.

4. The anti-reverse circuit according to claim 2, characterized in that: The switching unit comprises: A third switch, a first end of which is connected to the positive electrode of the load or the negative electrode of the load, a second end of which is connected to the control end of the first switch, and the control end of which is connected to the comparison unit; The third switch is configured to conduct between the first end and the second end thereof and control the first switch to be disconnected when receiving the first switching signal.

5. The anti-reverse circuit according to any one of claims 1 to 4, characterized in that: The first switch is a MOSFET; a drain of the first switch is connected to a power source, a source is connected to a load and the control circuit, and a gate is connected to the control circuit.

6. The anti-reverse circuit according to claim 5, characterized in that: The first switch is a P-type MOSFET; The drain of the first switch is connected to the positive electrode of the power supply, the source is connected to the positive electrode of the load and the control circuit, and the gate is connected to the negative electrode line and the control circuit.

7. The anti-reverse circuit according to claim 5, characterized in that: The first switch is an N-type MOSFET; The drain of the first switch is connected to the negative electrode of the power supply, the source is connected to the negative electrode of the load and the control circuit, and the gate is connected to the positive line and the control circuit.

8. The anti-reverse circuit according to any one of claims 1 to 4, characterized in that: Also includes: The energy storage unit is configured to output a voltage to the diode when the power supply voltage drops.

9. The anti-reverse circuit according to claim 8, characterized in that: The energy storage unit comprises: A first capacitor, one end of which is connected to the cathode of the diode and the other end of which is connected to the negative line; A first resistor is connected in parallel with the first capacitor.

10. An electronic device, characterized in that: The invention comprises the anti-reverse circuit according to any one of claims 1 to 9.

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