Protection circuit and electronic equipment

Abstract

The utility model provides a protection circuit and electronic equipment. The protection circuit comprises a switch module, a detection module, a driving module and an interlocking module. Specifically, the switch module is switched on when the input power supply is powered on so as to switch on a path from the input power supply to the load. The detection module detects the current and voltage of an input power supply, and outputs a protection signal when the input power supply is over-current and / or over-voltage. And the interlocking module continuously outputs an interlocking signal under the triggering of the protection signal, and resets when the input power supply is powered down. The driving module outputs a driving signal when receiving the interlocking signal; and the switch module is also cut off when receiving the driving signal. When over-current and / or over-voltage of the input power supply is detected, the input power supply is cut off quickly, so that the safety of the circuit is improved.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a protection circuit and electronic device. Background Technology

[0002] The input voltage of the auxiliary power supply circuit has a limited range. Exceeding this range may cause the components in the circuit to be subjected to excessively high voltage, leading to problems such as insulation breakdown and overheating, and ultimately damaging the circuit. When the auxiliary power supply circuit outputs overcurrent or short circuit, the current will increase significantly, exceeding the rated current of the components, causing excessive heating, accelerating component aging, or even burning out the components. It may also trigger the protection circuit. If the protection circuit fails, it will cause the entire system to malfunction, affecting the normal operation of the equipment, and in severe cases, it may lead to equipment damage or even a safety accident. Therefore, the voltage and current of the auxiliary power supply circuit must be strictly monitored and controlled. Utility Model Content

[0003] This application provides a protection circuit and electronic device that quickly cuts off the input power supply when an overcurrent and / or overvoltage is detected, thereby improving the circuit's safety.

[0004] In a first aspect, embodiments of this application provide a protection circuit, comprising a switching module, a detection module, a driving module, and an interlocking module. The switching module is connected between the input power supply and the detection module, and the detection module is connected between the switching module and the load. The detection module is also connected to the interlocking module, which is connected to the control terminal of the driving module and the input power supply, respectively. The driving module is connected to the control terminal of the switching module. The switching module is used to turn on when the input power supply is powered on, thereby establishing a path from the input power supply to the load. The detection module is used to detect the current and voltage of the input power supply and output a protection signal when the input power supply experiences overcurrent and / or overvoltage. The interlocking module is used to continuously output an interlocking signal upon triggering the protection signal and to reset when the input power supply is powered off. The driving module is used to output a driving signal upon receiving the interlocking signal; the switching module is also used to turn off upon receiving the driving signal.

[0005] In some embodiments, the protection signals include an overcurrent protection signal and an overvoltage protection signal, and the detection module includes an overcurrent detection unit and an overvoltage detection unit. The overcurrent detection unit is connected to the switch module and the interlock module, respectively, and the overvoltage detection unit is connected to the overcurrent detection unit, the interlock module, and the load, respectively. The overcurrent detection unit is used to detect the current of the input power supply and outputs the overcurrent protection signal when the input power supply experiences an overcurrent. The overvoltage detection unit is used to detect the voltage of the input power supply and outputs the overvoltage protection signal when the input power supply experiences an overvoltage.

[0006] In some embodiments, the overcurrent detection unit includes a resistor Ri, a switching transistor Q2, and a diode D1. The first end of the resistor Ri is connected to the first end of the switching transistor Q2 and the switching module, the second end of the resistor Ri is connected to the control terminal of the switching transistor Q2 and the load, the second end of the switching transistor Q2 is connected to the anode of the diode D1, and the cathode of the switching transistor Q2 is connected to the interlocking module.

[0007] In some embodiments, the overvoltage detection unit includes resistors R1, R6, and R7, a switching transistor Q5, and a diode D2. The first end of resistor R1 is connected to the first end of resistor R6, the overcurrent detection unit, and the load. The second end of resistor R1 is connected to the first end of the switching transistor Q5. The second end of resistor R6 is connected to the first end of resistor R7 and the control terminal of the switching transistor Q5. The second end of resistor R7 is grounded. The second end of the switching transistor Q5 is connected to the anode of diode D2, and the cathode of diode D2 is connected to the interlock module.

[0008] In some embodiments, the switching module includes a first switching unit and a second switching unit. The first switching unit is connected to both the control terminal of the second switching unit and the input power supply. The control terminal of the first switching unit is connected to the drive module, and the second switching unit is connected between the input power supply and the detection module. The first switching unit operates when the input power supply is powered on and stops operating when the drive signal is received. The second switching unit is turned on when the first switching unit is operating and turned off when the second switching unit stops operating.

[0009] In some embodiments, the first switching unit includes a switching transistor Q3 and a resistor R4. A first terminal of the resistor R4 is connected to the input power supply, and a second terminal of the resistor R4 is connected to both the control terminal of the switching transistor Q3 and the drive module. A first terminal of the switching transistor Q3 is connected to the second switching unit, and a second terminal of the switching transistor Q3 is grounded.

[0010] In some embodiments, the second switching unit includes a switching transistor Q1, a resistor R2, and a resistor R3. The first terminal of the switching transistor Q1 is connected to the first terminal of the resistor R2 and the input power supply, the second terminal of the switching transistor Q1 is connected to the detection module, the control terminal of the switching transistor Q1 is connected to the second terminal of the resistor R2 and the first terminal of the resistor R3, and the second terminal of the resistor R3 is connected to the first switching unit.

[0011] In some embodiments, the interlock module includes a switch Q6, a switch Q7, resistors R8, R9, and R11, a capacitor C4, and a diode D3. The first terminal of capacitor C4 is connected to the first terminal of resistor R8, the first terminal of switch Q6, and the input power supply. The second terminal of resistor R8 is connected to the first terminal of resistor R9 and the control terminal of switch Q6. The second terminal of capacitor C4 is connected to the second terminal of resistor R9 and the first terminal of switch Q7. The control terminal of switch Q7 is connected to the first terminal of resistor R11 and the detection module. The second terminal of switch Q6 is connected to the second terminal of resistor R11, the cathode of diode D3, and the control terminal of the drive module. The second terminal of switch Q7 and the anode of diode D3 are connected and grounded.

[0012] In some embodiments, the drive module includes a switch Q4 and a resistor R5. The control terminal of the switch Q4 is connected to the first terminal of the resistor R5 and the interlock module, the first terminal of the switch Q4 is connected to the control terminal of the switch module, and the second terminal of the switch Q4 and the second terminal of the resistor R5 are both grounded.

[0013] Secondly, embodiments of this application provide an electronic device that includes the protection circuit described above.

[0014] Unlike existing technologies, this application provides a protection circuit and electronic device. The protection circuit includes a switching module, a detection module, a driving module, and an interlocking module. Specifically, when the input power supply is powered on, the switching module is turned on. Since the switching module is connected between the input power supply and the detection module, its conduction creates a complete current path between the input power supply and the load. At this time, electrical energy is smoothly transferred from the input power supply through the switching module and the detection module to the load, and the load begins to work normally. Simultaneously, the detection module monitors the current and voltage of the input power supply in real time. Once an abnormal condition such as overcurrent (current exceeding a preset current range) and / or overvoltage (voltage exceeding a preset voltage range) occurs in the input power supply, the detection module reacts quickly and outputs a protection signal. Then, upon receiving the protection signal output by the detection module, the interlocking module is triggered and continuously outputs an interlocking signal. As long as the protection signal exists, the interlocking module maintains the state of outputting the interlocking signal. Simultaneously, the interlocking module is connected to the input power supply; if the input power supply fails, the interlocking module automatically resets and stops outputting the interlocking signal. The driving module outputs a driving signal upon receiving the interlocking signal from the interlocking module. Next, when the switching module receives the drive signal output by the drive module, it switches from on to off to cut off the connection between the input power supply and the load. This embodiment can promptly detect overcurrent and overvoltage conditions of the input power supply and quickly cut off the input power supply, reducing the possibility of damage to the load and circuit components due to abnormal current and voltage, thus providing circuit safety. Furthermore, the interlock module continuously outputs an interlock signal when triggered by a protection signal. Even if the state of the input power supply changes from overvoltage to normal, and / or from overcurrent to normal, the interlock module will continue to output an interlock signal to maintain the off state of the switching module. The interlock module will only reset when the input power supply is lost. This reduces the possibility of the circuit switching between on and off multiple times when the input power supply fluctuates, further improving circuit safety. Attached Figure Description

[0015] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0016] Figure 1 This is a structural block diagram of a protection circuit provided in an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of the circuit structure of a protection circuit provided in an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0019] The technical features involved in the various embodiments of this application described below do not conflict with each other and can be combined with each other.

[0020] When an element is described as "connected" to another element, it can be directly connected to the other element, or there may be one or more intervening elements between them.

[0021] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and are not limited in number; for example, a first object can be one or more.

[0022] Please see Figure 1 , Figure 1 This is a structural block diagram of a protection circuit 100 provided in an embodiment of this application.

[0023] This application provides a protection circuit 100, which includes a switch module 10, a detection module 20, a drive module 40, and an interlock module 30. The switch module 10 is connected between the input power supply (not shown, connection point VIN) and the detection module 20. The detection module 20 is connected between the switch module 10 and a load (not shown, connection point VOUT). The detection module 20 is also connected to the interlock module 30, which is connected to both the control terminal of the drive module 40 and the input power supply VIN. The drive module 40 is connected to the control terminal of the switch module 10.

[0024] Specifically, the switch module 10 is used to turn on when the input power supply VIN is powered on, thereby establishing a path from the input power supply VIN to the load. The detection module 20 is used to detect the current and voltage of the input power supply VIN, and outputs a protection signal when the input power supply VIN experiences overcurrent and / or overvoltage. The interlock module 30 is used to continuously output an interlock signal upon triggering the protection signal, and resets when the input power supply VIN is powered off. The drive module 40 is used to output a drive signal upon receiving the interlock signal; the switch module 10 is also used to turn off upon receiving the drive signal.

[0025] Input power supply VIN overcurrent refers to the input current supplied by the input power supply VIN exceeding a preset current threshold. In a circuit, each component and load has its rated current-carrying capacity. For example, a load with a rated current of 2A is considered to be in overcurrent condition if the input current exceeds 2A.

[0026] Input power supply VIN overvoltage refers to the input voltage of the input power supply VIN exceeding a preset voltage threshold. For example, if the preset voltage threshold is 15V, then an input voltage exceeding 15V is considered overvoltage.

[0027] The protection signal is output by the detection module 20 when it detects an overcurrent and / or overvoltage condition in the input power supply VIN. This signal is a trigger signal used to inform the interlock module 30 that an abnormality has occurred in the circuit and the protection mechanism needs to be activated. The protection signal can be a voltage signal, a current signal, or a digital signal, depending on the circuit design of the detection module 20. For example, when an overcurrent is detected, the detection module 20 may output a high-level voltage signal as a protection signal.

[0028] The interlock signal is a signal continuously output by the interlock module 30 after receiving a protection signal. The main function of the interlock signal is to ensure the protection mechanism remains effective when a circuit malfunctions. Even if the malfunction disappears quickly, the interlock signal will remain for a period to prevent power restoration before the potential malfunction is completely eliminated. The interlock module 30 will only reset and stop outputting the interlock signal when the input power supply VIN is lost. The interlock signal can also be an electrical signal of different forms, intended to be transmitted to the drive module 40 to trigger corresponding actions.

[0029] The drive signal is the signal output by the drive module 40 after receiving the interlock signal. The function of the drive signal is to control the operation of the switch module 10. When the switch module 10 receives the drive signal, it changes from the on state to the off state, thereby cutting off the path from the input power supply VIN to the load and protecting the circuit and load. The drive signal typically has sufficient power and an appropriate voltage level to ensure reliable control of the state transitions of the switch module 10. For example, for a switch module 10 using a MOSFET as the switching element, the drive signal might be a pulse signal with a specific voltage value used to change the on and off states of the MOSFET.

[0030] In practical applications, when the input power supply VIN is powered on, the switching module 10 is turned on, establishing a path from the input power supply VIN to the load, enabling the load to receive power normally. At this time, the detection module 20 monitors the current and voltage of the input power supply VIN. If the current and voltage are within the normal range, the entire circuit maintains a stable operating state, and the interlocking module 30 and the drive module 40 do not generate signals that affect the operation of the circuit.

[0031] When the detection module 20 detects an overcurrent and / or overvoltage condition in the input power supply VIN, it outputs a protection signal. This signal triggers the interlock module 30, causing it to continuously output an interlock signal. Upon receiving the interlock signal, the drive module 40 outputs a drive signal. The switch module 10 cuts off upon receiving the drive signal, thereby disconnecting the path from the input power supply VIN to the load and protecting the load and other components in the circuit from overcurrent or overvoltage damage. When the input power supply VIN is de-energized, the interlock module 30 resets, preparing for the next possible protection action. Once the input power supply VIN is powered on again, the circuit will repeat the above process, continuing to monitor and protect the current and voltage of the input power supply.

[0032] Please see Figure 2 , Figure 2 This is a schematic diagram of the circuit structure of a protection circuit 100 provided in an embodiment of this application.

[0033] In some embodiments, such as Figure 2 As shown, the protection signals include overcurrent protection signals and overvoltage protection signals. The detection module 20 includes an overcurrent detection unit 21 and an overvoltage detection unit 22. The overcurrent detection unit 21 is connected to both the switch module 10 and the interlock module 30, while the overvoltage detection unit 22 is connected to the overcurrent detection unit 21, the interlock module 30, and the load RL (which can be considered as a resistor RL). Specifically, the overcurrent detection unit 21 detects the current of the input power supply VIN and outputs an overcurrent protection signal when the input power supply VIN experiences an overcurrent. The overvoltage detection unit 22 detects the voltage of the input power supply VIN and outputs an overvoltage protection signal when the input power supply VIN experiences an overvoltage.

[0034] In practical applications, the overcurrent detection unit 21 monitors the current of the input power supply VIN in real time using a specific current detection method (such as using a sampling resistor). When no overcurrent occurs in the input power supply VIN, that is, when the input current is less than the preset current threshold, the overcurrent detection unit 21 does not generate an overcurrent protection signal. Once the current of the input power supply VIN exceeds the preset current threshold, that is, when the input power supply VIN experiences an overcurrent, the overcurrent detection unit 21 will output an overcurrent protection signal according to its internal circuit logic.

[0035] The overvoltage detection unit 22 continuously monitors the input voltage of the input power supply VIN. Typically, a voltage divider circuit or similar method is used to convert the input voltage into a voltage signal suitable for processing by the detection circuit for accurate monitoring. When the input power supply VIN is not overvoltaged, i.e., the input voltage is less than a preset voltage threshold, the overvoltage detection unit 22 does not generate an overvoltage protection signal. When the voltage of the input power supply VIN exceeds the preset voltage threshold, the overvoltage detection unit 22 will output an overvoltage protection signal based on its internal circuit design.

[0036] Overcurrent detection unit 21 and overvoltage detection unit 22 independently monitor the current and voltage of the input power supply VIN. Under normal operating conditions, neither outputs a protection signal. When overcurrent or overvoltage occurs, the corresponding detection unit outputs a corresponding protection signal. These protection signals are transmitted to the interlock module 30 to further control the drive module 40 and the switching module 10, ultimately cutting off the path from the input power supply VIN to the load RL, thus protecting the circuit and the load. Furthermore, the two detection units operate independently, ensuring timely triggering of protection actions regardless of whether overcurrent or overvoltage occurs, guaranteeing the safe and stable operation of the circuit.

[0037] In some embodiments, the overcurrent detection unit 21 includes a resistor Ri, a switching transistor Q2, and a diode D1. The first end of the resistor Ri is connected to the first end of the switching transistor Q2 and the switching module 10, the second end of the resistor Ri is connected to the control terminal of the switching transistor Q2 and the load RL, the second end of the switching transistor Q2 is connected to the anode of the diode D1, and the cathode of the switching transistor Q2 is connected to the interlock module 30.

[0038] In some embodiments, the overvoltage detection unit 22 includes resistors R1, R6, and R7, a switching transistor Q5, and a diode D2. The first end of resistor R1 is connected to the first end of resistor R6, the overcurrent detection unit 21, and the load RL. The second end of resistor R1 is connected to the first end of switching transistor Q5. The second end of resistor R6 is connected to the first end of resistor R7 and the control terminal of switching transistor Q5. The second end of resistor R7 is grounded. The second end of switching transistor Q5 is connected to the anode of diode D2, and the cathode of diode D2 is connected to the interlock module 30.

[0039] The following is Figure 2 The working principles of the overcurrent detection unit 21 and the overvoltage detection unit 22 are briefly explained.

[0040] In practical applications, when an overcurrent occurs in the input power supply VIN (i.e., when the input current of the input power supply VIN exceeds the preset current threshold), the voltage at the control terminal of the switching transistor Q2 is greater than its turn-on voltage, thus turning on the switching transistor Q2. The negative terminal of diode D1 outputs an overcurrent protection signal (i.e., a high-level signal). This overcurrent protection signal is sent to the interlock module 30 to trigger subsequent protection actions, preventing damage to the circuit and load due to excessive current.

[0041] Specifically, the preset current threshold can be adjusted by adjusting the resistance value of resistor Ri. Let the on-state voltage of switch Q2 (its BE on-state voltage) be VF, then the preset current threshold is Imax = VF / Ri, where Ri is the resistance value of resistor Ri.

[0042] In practical applications, when an overvoltage occurs in the input power supply VIN (i.e., when the input voltage of the input power supply VIN exceeds a preset voltage threshold), the voltage at the control terminal of the switching transistor Q5 (i.e., the voltage across resistor R7 after the input voltage is divided by resistors R6 and R7) is greater than its turn-on voltage. This causes the switching transistor Q5 to turn on, and the negative terminal of diode D2 outputs an overvoltage protection signal (i.e., a high-level signal). This overvoltage protection signal is transmitted to the interlock module 30, which then activates the corresponding protection mechanism to prevent excessive voltage from adversely affecting the load and circuit components.

[0043] Specifically, the preset voltage threshold can be adjusted by adjusting the resistance values ​​of resistors R6 and R7.

[0044] In some embodiments, the detection module 20 further includes a resistor R10. The first end of the resistor R10 is connected to both the overcurrent detection unit 21 and the overvoltage detection unit 22, and the second end of the resistor R10 is connected to the interlock module 30. The resistor R10 is used for current limiting.

[0045] In this embodiment, taking a PNP transistor as an example, the base of the PNP transistor is the control terminal of the switch Q2, the emitter of the PNP transistor is the first terminal of the switch Q2, and the collector of the PNP transistor is the second terminal of the switch Q2. Similarly, taking an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switch Q5, the collector of the NPN transistor is the first terminal of the switch Q5, and the emitter of the NPN transistor is the second terminal of the switch Q5.

[0046] In addition, switching transistors Q2 and Q5 can be any controllable switch, such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field-effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices, etc.

[0047] In some embodiments, such as Figure 2 As shown, the switch module 10 includes a first switch unit 11 and a second switch unit 12. The first switch unit 11 is connected to both the control terminal of the second switch unit 12 and the input power supply VIN. The control terminal of the first switch unit 11 is connected to the drive module 40. The second switch unit 12 is connected between the input power supply VIN and the detection module 20. Specifically, the first switch unit 11 operates when the input power supply VIN is powered on and stops operating when a drive signal is received. The second switch unit 12 is turned on when the first switch unit 11 is operating and turned off when the second switch unit 12 stops operating.

[0048] In some embodiments, the first switching unit 11 includes a switching transistor Q3 and a resistor R4. The first end of the resistor R4 is connected to the input power supply VIN, and the second end of the resistor R4 is connected to both the control terminal of the switching transistor Q3 and the drive module 40. The first end of the switching transistor Q3 is connected to the second switching unit 12, and the second end of the switching transistor Q3 is grounded.

[0049] In some embodiments, the second switching unit 12 includes a switching transistor Q1, a resistor R2, and a resistor R3. The first terminal of the switching transistor Q1 is connected to the first terminal of the resistor R2 and the input power supply VIN, the second terminal of the switching transistor Q1 is connected to the detection module 20, the control terminal of the switching transistor Q1 is connected to the second terminal of the resistor R2 and the first terminal of the resistor R3, and the second terminal of the resistor R3 is connected to the first switching unit 11.

[0050] The following is Figure 2 The working principles of the first switching unit 11 and the second switching unit 12 are briefly described.

[0051] When the input power supply VIN is powered on, the control terminal of the switch Q3 is at a high level, so the switch Q3 is turned on. This causes the control terminal of the switch Q1 to be at a low level, so the switch Q1 is turned on. Thus, the input power supply VIN can supply power to the load RL.

[0052] Simultaneously, the detection module 20 monitors the current and voltage of the input power supply VIN in real time. If the detection module 20 detects overcurrent and / or overvoltage in the input power supply VIN, it outputs a protection signal to the interlock module 30. Then, the interlock module 30 continuously outputs an interlock signal upon triggering the protection signal. Based on this interlock signal, the drive module 40 outputs a drive signal (low-level signal) to the control terminal of the switch Q3. The switch Q3 then turns off based on this drive signal, and the control terminal of the switch Q1 turns high, causing the switch Q1 to also turn off. This achieves the disconnection of the input power supply in the event of overcurrent and / or overvoltage in the input power supply VIN.

[0053] In this embodiment, taking a PNP transistor as an example, the base of the PNP transistor is the control terminal of the switch Q1, the emitter of the PNP transistor is the first terminal of the switch Q1, and the collector of the PNP transistor is the second terminal of the switch Q1. Taking an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switch Q3, the collector of the NPN transistor is the first terminal of the switch Q3, and the emitter of the NPN transistor is the second terminal of the switch Q3.

[0054] In addition, switching transistors Q1 and Q3 can be any controllable switch, such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field-effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices, etc.

[0055] In some embodiments, such as Figure 2 As shown, the interlock module 30 includes switching transistors Q6 and Q7, resistors R8, R9, and R11, capacitor C4, and diode D3. The first terminal of capacitor C4 is connected to the first terminal of resistor R8, the first terminal of switching transistor Q6, and the input power supply VIN. The second terminal of resistor R8 is connected to the first terminal of resistor R9 and the control terminal of switching transistor Q6. The second terminal of capacitor C4 is connected to the second terminal of resistor R9 and the first terminal of switching transistor Q7. The control terminal of switching transistor Q7 is connected to the first terminal of resistor R11 and the detection module 20. The second terminal of switching transistor Q6 is connected to the second terminal of resistor R11, the cathode of diode D3, and the control terminal of drive module 40. The second terminal of switching transistor Q7 and the anode of diode D3 are connected and grounded.

[0056] The following is Figure 2 The working principle of the interlock module 30 is briefly explained.

[0057] In practical applications, when the control terminal of switch Q7 receives an overcurrent protection signal (high-level signal) and / or an overvoltage protection signal (high-level signal), switch Q7 turns on. Simultaneously, because switch Q7 is turned on, capacitor C4 begins to charge, and switch Q6 turns on because its control terminal is pulled low. The input power supply VIN flows through switch Q6 to the second terminal of resistor R11 (i.e.,...). Figure 2 The V2 point outputs a high-level signal (i.e., an interlock signal).

[0058] When the overcurrent and / or overvoltage disappears, that is, when the input power supply VIN returns to normal, due to the presence of capacitor C4, the control terminal of switch Q7 remains at a high level (the power supply VIN passes through switch Q6 and resistor R11 to the control terminal of switch Q7), thus... Figure 2The voltage at point V2 is locked at a high level (i.e., an interlock signal). That is, even if the current and voltage recover, and switching transistors Q2 and Q5 are not turned on, the control terminal of switching transistor Q7 remains high, thus keeping switching transistor Q7 on, and switching transistor Q6 also on. Figure 2 The voltage level at point V2 is locked at a high level (i.e., an interlock signal). The interlock module 30 will only reset (i.e., point V2 will go low) after the input power supply VIN is de-energized and the voltage across capacitor C4 drops.

[0059] In this embodiment, taking a PNP transistor as an example, the base of the PNP transistor is the control terminal of the switch Q6, the emitter of the PNP transistor is the first terminal of the switch Q6, and the collector of the PNP transistor is the second terminal of the switch Q6. Taking an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switch Q7, the collector of the NPN transistor is the first terminal of the switch Q7, and the emitter of the NPN transistor is the second terminal of the switch Q7.

[0060] In addition, switching transistors Q6 and Q7 can be any controllable switch, such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field-effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices, etc.

[0061] In some embodiments, the drive module 40 includes a switch Q4 and a resistor R5. The control terminal of the switch Q4 is connected to the first terminal of the resistor R5 and the interlock module 30, the first terminal of the switch Q4 is connected to the control terminal of the switch module 10, and the second terminals of the switch Q4 and the second terminals of the resistor R5 are both grounded.

[0062] In this embodiment, when an interlock signal (e.g., a high-level signal) is input to the control terminal of switch Q4, the connection between the first and second terminals of switch Q4 is turned on. The control terminal of switch Q3 in switch module 10 is grounded, thus disconnecting the connection between the first and second terminals of switch Q3, and switch Q3 stops working. Subsequently, since the control terminal of switch Q1 is not grounded due to switch Q3's inactivity, switch Q1 is turned off, meaning the connection between the first and second terminals of switch Q1 is disconnected, thereby breaking the path between the input power supply VIN and the load RL.

[0063] In this embodiment, taking the switch Q4 as an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switch Q4, the collector of the NPN transistor is the first terminal of the switch Q4, and the emitter of the NPN transistor is the second terminal of the switch Q4.

[0064] In addition, the switching transistor Q4 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field-effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0065] Among them, such as Figure 2 As shown, inductors L1 and L2, as well as a voltage regulator U1, can be connected in series between the input power supply VIN and the load RL. A capacitor C1 can be placed at the input terminal of the voltage regulator U1, and capacitors C2 and C3 can be placed at the output terminal of the voltage regulator U1.

[0066] This application provides a protection circuit, which includes a switching module, a detection module, a driving module, and an interlocking module. Specifically, when the input power supply is powered on, the switching module is turned on. Since the switching module is connected between the input power supply and the detection module, its conduction creates a complete current path between the input power supply and the load. At this time, electrical energy is smoothly transferred from the input power supply through the switching module and the detection module to the load, and the load begins to work normally. Simultaneously, the detection module monitors the current and voltage of the input power supply in real time. Once the input power supply experiences an overcurrent (current exceeding a preset current range) and / or overvoltage (voltage exceeding a preset voltage range) abnormal condition, the detection module reacts quickly and outputs a protection signal. Then, upon receiving the protection signal output by the detection module, the interlocking module is triggered and continuously outputs an interlocking signal. As long as the protection signal exists, the interlocking module maintains the state of outputting the interlocking signal. Simultaneously, the interlocking module is connected to the input power supply; if the input power supply fails, the interlocking module automatically resets and stops outputting the interlocking signal. The driving module outputs a driving signal upon receiving the interlocking signal from the interlocking module. Next, when the switching module receives the drive signal output by the drive module, it switches from on to off to cut off the connection between the input power supply and the load. This embodiment can promptly detect overcurrent and overvoltage conditions of the input power supply and quickly cut off the input power supply, reducing the possibility of damage to the load and circuit components due to abnormal current and voltage, thus providing circuit safety. Furthermore, the interlock module continuously outputs an interlock signal when triggered by a protection signal. Even if the state of the input power supply changes from overvoltage to normal, and / or from overcurrent to normal, the interlock module will continue to output an interlock signal to maintain the off state of the switching module. The interlock module will only reset when the input power supply is lost. This reduces the possibility of the circuit switching between on and off multiple times when the input power supply fluctuates, further improving circuit safety.

[0067] This application also provides an electronic device, which includes the protection circuit 100 as described above.

[0068] The specific structure and working principle of the protection circuit 100 can be referred to the above embodiments, and will not be repeated here.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, and there are many other variations of different aspects of this application as described above. For the sake of brevity, they are not provided in detail; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A protection circuit, characterized by, The protection circuit comprises a switching module, a detection module, a driving module and an interlocking module; The switching module is connected between an input power supply and the detection module, the detection module is connected between the switching module and a load, the detection module is further connected with the interlocking module, the interlocking module is connected with a control end of the driving module and the input power supply respectively, and the driving module is connected with a control end of the switching module; The switching module is used to turn on when the input power supply is powered on, so as to turn on the path from the input power supply to the load; The detection module is used to detect the current and voltage of the input power supply, and output a protection signal when the input power supply is overcurrent and / or overvoltage; The interlocking module is used to continuously output an interlocking signal under the triggering of the protection signal, and reset when the input power supply is powered off; The driving module is used to output a driving signal when receiving the interlocking signal; and the switching module is further used to cut off when receiving the driving signal.

2. The protection circuit of claim 1, wherein The protection signal comprises an overcurrent protection signal and an overvoltage protection signal, and the detection module comprises an overcurrent detection unit and an overvoltage detection unit; The overcurrent detection unit is connected with the switching module and the interlocking module respectively, and the overvoltage detection unit is connected with the overcurrent detection unit, the interlocking module and the load respectively; The overcurrent detection unit is used to detect the current of the input power supply, and output the overcurrent protection signal when the input power supply is overcurrent; The overvoltage detection unit is used to detect the voltage of the input power supply, and output the overvoltage protection signal when the input power supply is overvoltage.

3. The protection circuit of claim 2, wherein, The overcurrent detection unit comprises a resistor Ri, a switching tube Q2 and a diode D1; The first end of the resistor Ri is connected with the first end of the switching tube Q2 and the switching module respectively, the second end of the resistor Ri is connected with the control end of the switching tube Q2 and the load respectively, the second end of the switching tube Q2 is connected with the anode of the diode D1, and the cathode of the switching tube Q2 is connected with the interlocking module.

4. The protection circuit of claim 2, wherein, The overvoltage detection unit comprises a resistor R1, a resistor R6, a resistor R7, a switching tube Q5 and a diode D2; The first end of the resistor R1 is connected with the first end of the resistor R6, the overcurrent detection unit and the load respectively, the second end of the resistor R1 is connected with the first end of the switching tube Q5, the second end of the resistor R6 is connected with the first end of the resistor R7 and the control end of the switching tube Q5 respectively, the second end of the resistor R7 is grounded, the second end of the switching tube Q5 is connected with the anode of the diode D2, and the cathode of the diode D2 is connected with the interlocking module.

5. The protection circuit of claim 1, wherein, The switching module comprises a first switching unit and a second switching unit; The first switching unit is connected with the control end of the second switching unit and the input power supply respectively, the control end of the first switching unit is connected with the driving module, and the second switching unit is connected between the input power supply and the detection module; The first switching unit is used to work when the input power supply is powered on, and stop working when receiving the driving signal; The second switch unit is used for conducting when the first switch unit works and cutting off when the second switch unit stops working.

6. The protection circuit of claim 5, wherein, The first switch unit comprises a switch tube Q3 and a resistor R4. The first end of the resistor R4 is connected with the input power supply, the second end of the resistor R4 is connected with the control end of the switch tube Q3 and the driving module respectively, the first end of the switch tube Q3 is connected with the second switch unit, and the second end of the switch tube Q3 is grounded.

7. The protection circuit of claim 5, wherein, The second switch unit comprises a switch tube Q1, a resistor R2 and a resistor R3. The first end of the switch tube Q1 is connected with the first end of the resistor R2 and the input power supply respectively, the second end of the switch tube Q1 is connected with the detection module, the control end of the switch tube Q1 is connected with the second end of the resistor R2 and the first end of the resistor R3 respectively, and the second end of the resistor R3 is connected with the first switch unit.

8. The protection circuit of claim 1, wherein, The interlocking module comprises a switch tube Q6, a switch tube Q7, a resistor R8, a resistor R9, a resistor R11, a capacitor C4 and a diode D3. The first end of the capacitor C4 is connected with the first end of the resistor R8, the first end of the switch tube Q6 and the input power supply respectively, the second end of the resistor R8 is connected with the first end of the resistor R9 and the control end of the switch tube Q6 respectively, the second end of the capacitor C4 is connected with the second end of the resistor R9 and the first end of the switch tube Q7 respectively, the control end of the switch tube Q7 is connected with the first end of the resistor R11 and the detection module respectively, the second end of the switch tube Q6 is connected with the second end of the resistor R11, the negative electrode of the diode D3 and the control end of the driving module respectively, and the second end of the switch tube Q7 and the positive electrode of the diode D3 are connected and grounded.

9. The protection circuit of claim 1, wherein, The driving module comprises a switch tube Q4 and a resistor R5. The control end of the switch tube Q4 is connected with the first end of the resistor R5 and the interlocking module respectively, the first end of the switch tube Q4 is connected with the control end of the switch module, and the second end of the switch tube Q4 and the second end of the resistor R5 are both grounded.

10. An electronic device, comprising: The electronic device comprises the protection circuit according to any one of claims 1 to 9.

Images