Overvoltage protection circuit and electronic equipment

Abstract

The embodiment of the invention provides an overvoltage protection circuit and electronic equipment, and the overvoltage protection circuit comprises a first switching tube which comprises a first electrode, a second electrode and a third electrode; the first electrode is used for receiving input voltage; the second electrode is grounded; one end of the voltage dividing module is connected with the first electrode of the first switch tube; one end of the signal processing module is connected with the other end of the voltage dividing module; one end of the driving module is connected with the other end of the signal processing module, and the other end of the driving module is connected with the third electrode of the first switching tube; the signal processing module is used for collecting the first voltage signal output by the voltage dividing module, converting the first voltage signal into a second voltage signal and inputting the second voltage signal into the driving module; and the driving module is used for driving the third electrode of the first switching tube through the second voltage signal. The cost for realizing overvoltage protection is reduced, and the complexity of the overvoltage protection circuit is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage control, and in particular to a voltage protection circuit and an electronic device. Background Art

[0002] An overvoltage protection device is a device used to protect electrical equipment and systems from damage caused by excessive voltage. The overvoltage protection device in related technologies needs to cooperate with the controller, overvoltage judgment unit, voltage acquisition unit and drive circuit through a control system. The voltage acquisition unit compares the collected voltage with multiple reference voltages and outputs the judgment result. The drive circuit is then controlled to protect the switch tube from overvoltage. However, the implementation cost and complexity of this method are relatively high. Summary of the invention

[0003] In view of the above problems, embodiments of the present invention are proposed to provide an overvoltage protection circuit and an electronic device that overcome the above problems or at least partially solve the above problems.

[0004] In order to solve the above problem, an embodiment of the present invention discloses an overvoltage protection circuit, including:

[0005] The first switch tube comprises a first electrode, a second electrode and a third electrode; the first electrode is used to receive an input voltage; the second electrode is grounded;

[0006] A voltage dividing module, one end of which is connected to the first electrode of the first switch tube;

[0007] A signal processing module, one end of which is connected to the other end of the voltage dividing module;

[0008] A driving module, one end of which is connected to the other end of the signal processing module, and the other end of which is connected to the third electrode of the first switch tube;

[0009] The signal processing module is used to collect the first voltage signal output by the voltage dividing module, convert the first voltage signal into a second voltage signal, and input the second voltage signal to the driving module;

[0010] The driving module is used to drive the third electrode of the first switch tube through the second voltage signal.

[0011] Optionally, the voltage dividing module includes: a first resistor and a second resistor;

[0012] One end of the first resistor is connected to the first electrode of the first switch tube, and the other end of the first resistor is respectively connected to one end of the second resistor and the signal processing module;

[0013] The other end of the second resistor is grounded.

[0014] Optionally, the signal processing module includes: a third resistor, a fourth resistor, a fifth resistor, a first operational amplifier and a second operational amplifier;

[0015] One end of the third resistor is connected to the voltage divider module, and the other end of the third resistor is respectively connected to one end of the fourth resistor and the inverting input end of the first operational amplifier;

[0016] The other end of the fourth resistor is connected to the output end of the first operational amplifier and the non-inverting input end of the second operational amplifier respectively;

[0017] One end of the fifth resistor is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the fifth resistor is grounded;

[0018] The inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier and the driving module respectively.

[0019] Optionally, the driving module includes: a second switch tube, a sixth resistor, a seventh resistor, a first diode, a second diode and a driving integrated circuit;

[0020] The first electrode of the second switch tube is connected to the signal processing module, the second electrode of the second switch tube is connected to one end of the sixth resistor, and the third electrode of the second switch tube is connected to the anode of the first diode;

[0021] The other end of the sixth resistor is respectively connected to the third electrode of the first switch tube and one end of the seventh resistor;

[0022] The other end of the seventh resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to the driving integrated circuit and the cathode of the first diode respectively.

[0023] Optionally, the overvoltage protection circuit further includes:

[0024] A power supply module, one end of which is respectively connected to the first electrode of the first switch tube and one end of the voltage divider module, and the other end of which is connected to the second electrode of the first switch tube and a ground wire.

[0025] Optionally, the power supply module includes: a power supply, a capacitor, an inductor and a third diode;

[0026] One end of the power supply is respectively connected to one end of the capacitor, one end of the inductor and the cathode of the third diode; the other end of the power supply is respectively connected to the other end of the capacitor, the second electrode of the first switch tube and the ground wire;

[0027] The other end of the inductor is respectively connected to the anode of the third diode, the first electrode of the first switch tube and one end of the voltage divider module.

[0028] Optionally, the first switch tube is an insulated gate bipolar transistor; the first electrode of the first switch tube is a collector; the second electrode of the first switch tube is an emitter; and the third electrode of the first switch tube is a gate.

[0029] Optionally, the second switch tube is a metal oxide semiconductor field effect transistor; the first electrode of the second switch tube is a gate; the second electrode of the second switch tube is a drain; and the third electrode of the switch tube is a source.

[0030] Optionally, the insulated gate bipolar transistor is a damped insulated gate bipolar transistor.

[0031] An embodiment of the present invention further discloses an electronic device, wherein the electronic device comprises the overvoltage protection circuit as described above.

[0032] The embodiments of the present invention include the following advantages:

[0033] An embodiment of the present invention discloses an overvoltage protection circuit. The present invention receives an input voltage through a first electrode of a first switch tube, one end of a voltage divider module is connected to the first electrode of the first switch tube, the voltage divider module receives the input voltage and performs voltage division processing on the input voltage to obtain a first voltage signal, and inputs the first voltage signal to a signal processing module, one end of the signal processing module is connected to the other end of the voltage divider module, the signal processing module converts the first voltage signal into a second voltage signal, and inputs the second voltage signal to a driving module, one end of the driving module is connected to the other end of the signal processing module, and the other end of the driving module is connected to the third electrode of the first switch tube. Finally, the driving module drives the third electrode of the first switch tube through the second voltage signal, thereby performing overvoltage protection. At the same time, when performing overvoltage protection, there is no need for cooperation between the control system and the overvoltage judgment unit, which reduces the cost of implementing overvoltage protection and reduces the complexity of the overvoltage protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a structural block diagram of an overvoltage protection circuit provided by an embodiment of the present invention;

[0035] Figure 2 is a structural block diagram of another overvoltage protection circuit provided by an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of a transfer characteristic curve of a second switch tube provided in an embodiment of the present invention.

[0037] Description of reference numerals:

[0038] 1-first switch tube, 2-voltage divider module, 21-first resistor, 22-second resistor, 3-signal processing module, 31-third resistor, 32-fourth resistor, 33-fifth resistor, 34-first operational amplifier, 35-second operational amplifier, 4-driving module, 41-second switch tube, 42-sixth resistor, 43-seventh resistor, 44-first diode, 45-second diode, 46-driving integrated circuit, 5-power supply module 5, 51-power supply, 52-capacitor, 53-inductor, 54-third diode. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] In the related technology, the overvoltage protection device needs to cooperate with the controller, overvoltage judgment unit, voltage acquisition unit and driving circuit through the control system. The voltage acquisition unit compares the collected voltage with multiple reference voltages and outputs the judgment result. The overvoltage protection of the switch tube is then performed by controlling the driving circuit. The implementation cost and complexity of this method are relatively high. In order to solve this technical problem, one of the core concepts of an embodiment of the present invention is that the present invention receives an input voltage through a first electrode of a first switch tube, one end of a voltage divider module is connected to the first electrode of the first switch tube, the voltage divider module receives the input voltage and performs voltage division processing on the input voltage to obtain a first voltage signal, and inputs the first voltage signal to a signal processing module, one end of the signal processing module is connected to the other end of the voltage divider module, the signal processing module converts the first voltage signal into a second voltage signal, and inputs the second voltage signal to a driving module, one end of the driving module is connected to the other end of the signal processing module, and the other end of the driving module is connected to the third electrode of the first switch tube. Finally, the driving module drives the third electrode of the first switch tube through the second voltage signal, thereby performing overvoltage protection. At the same time, when performing overvoltage protection, there is no need for cooperation between the control system and the overvoltage judgment unit, which reduces the cost of implementing overvoltage protection and reduces the complexity of the overvoltage protection circuit.

[0041] Reference Figure 1 , shows a structural block diagram of an overvoltage protection circuit provided by an embodiment of the present invention, and the overvoltage protection circuit may specifically include:

[0042] The first switch tube 1 comprises a first electrode, a second electrode and a third electrode; the first electrode is used to receive an input voltage; the second electrode is grounded;

[0043] A voltage dividing module 2, one end of which is connected to the first electrode of the first switching tube 1;

[0044] A signal processing module 3, one end of which is connected to the other end of the voltage dividing module 2;

[0045] A driving module 4, one end of which is connected to the other end of the signal processing module 3, and the other end of which is connected to the third electrode of the first switch tube 1;

[0046] The signal processing module 3 is used to collect the first voltage signal output by the voltage dividing module 2, convert the first voltage signal into a second voltage signal, and input the second voltage signal to the driving module 4;

[0047] The driving module 4 is used to drive the third electrode of the first switch tube 1 through the second voltage signal.

[0048] In the present invention, the first electrode of the first switch tube 1 and the voltage divider module 2 can receive the same input voltage. When the input voltage is a larger transient voltage, that is, a larger transient voltage is generated at the first electrode of the first switch tube 1, at this time, the transient voltage can be converted into a smaller first voltage signal through the voltage divider module 2, and the first voltage signal is input to the signal processing module 3. After receiving the first voltage signal, the signal processing module 3 can convert the first voltage signal into a second voltage signal, and input the second voltage signal to the driving module 4, and then the driving module 4 can drive the third electrode of the first switch tube 1 according to the second voltage signal, that is, the driving module 4 can control the state of the first switch tube 1 according to the second voltage signal.

[0049] In the present invention, the first switch tube 1 is an insulated gate bipolar transistor (IGBT); the first electrode of the first switch tube 1 is a collector; the second electrode of the first switch tube 1 is an emitter; and the third electrode of the first switch tube 1 is a gate.

[0050] IGBT is a power semiconductor device that combines the advantages of MOSFET (Metal-Oxide-SemiconductorField-EffectTransistor) and BJT (Bipolar JunctionTransistor), and is widely used in high-voltage and high-current power electronic systems. IGBT is a three-terminal device, including: Gate: used to control the switch of the device. Collector: connected to the high voltage end. Emitter: connected to the low voltage end. The working principle of IGBT is based on the control of gate voltage, and the flow of current is controlled by adjusting the gate voltage. The working principle of IGBT can be divided into two stages: On-state: When a positive voltage is applied to the gate, the MOSFET part is turned on, forming a low-impedance channel. The low-impedance channel makes the BJT part turn on, and the current flows from the collector to the emitter. Off-state: When the gate voltage decreases or becomes negative, the MOSFET part is turned off, and the BJT part is also turned off, and the current stops flowing. The characteristics of IGBT are: High voltage and high current capability: IGBT can withstand high voltage (hundreds of volts to thousands of volts) and high current (tens of amperes to thousands of amperes). Low conduction loss: Compared with BJT, IGBT has lower on-resistance, so conduction loss is smaller. Fast switching speed: Compared with BJT, IGBT has faster switching speed and is suitable for high-frequency applications. Simple drive: Similar to MOSFET, the gate drive circuit of IGBT is relatively simple. The advantages of IGBT are: High efficiency: low conduction loss and fast switching speed improve system efficiency. High reliability: suitable for high voltage and high current environment, with a long service life. Flexibility: suitable for a variety of power electronics applications, from low power to high power.

[0051] In the present invention, the insulated gate bipolar transistor is an insulated gate bipolar transistor with damping, that is, the first switch tube 1 in the present application can be an insulated gate bipolar transistor with damping.

[0052] The damped insulated gate bipolar transistor is a design that adds a damping circuit to the IGBT circuit to reduce the voltage and current spikes during the switching process, protect the IGBT from overvoltage and overcurrent damage, and improve the reliability and efficiency of the system. The main functions of the damping circuit are: Reduce voltage spikes: During the IGBT switching process, the damping circuit can absorb and suppress voltage spikes to prevent overvoltage from damaging the IGBT. Reduce current spikes: During the IGBT switching process, the damping circuit can absorb and suppress current spikes to prevent overcurrent from damaging the IGBT. Improve switching efficiency: By reducing energy loss during the switching process, the damping circuit can improve the switching efficiency of the IGBT. Extend device life: By protecting the IGBT from overvoltage and overcurrent damage, the damping circuit can extend the service life of the IGBT. The working principle of the damping circuit can be divided into the following stages: Turn-on stage: When the IGBT is turned on, the capacitor 52 of the damping circuit is charged to absorb the voltage spike. The resistor consumes energy and reduces the voltage and current spikes. Turn-off phase: When the IGBT is turned off, the capacitor 52 of the damping circuit discharges and absorbs the voltage spike. The diode provides a fast discharge path, and the resistor consumes energy and reduces the voltage and current spikes. When designing the damping circuit, the following factors need to be considered: Capacitor 52 value (C): Select the appropriate capacitor 52 value according to the switching frequency and voltage spike of the IGBT. Resistor value (R): Select the appropriate resistor value according to the capacitor 52 value and the switching frequency to ensure a balance between energy consumption and voltage suppression. Diode (D): Select a fast recovery diode (FRD) to provide a fast discharge path. Layout and wiring: Ensure that the layout and wiring of the damping circuit are reasonable to reduce the influence of parasitic inductance 53 and capacitor 52. The advantages of the damping circuit are: Protect IGBT: Protect IGBT from overvoltage and overcurrent damage by reducing voltage and current spikes. Improve efficiency: Improve the switching efficiency of IGBT by reducing energy loss during switching. Extend life: Extend the service life of IGBT by protecting IGBT from overvoltage and overcurrent damage.

[0053] Reference Figure 2 , shows a structural block diagram of another overvoltage protection circuit provided by an embodiment of the present invention, the voltage divider module 2 includes: a first resistor 21 and a second resistor 22; one end of the first resistor 21 is connected to the first electrode of the first switch tube 1, and the other end of the first resistor 21 is respectively connected to one end of the second resistor 22 and the signal processing module 3; the other end of the second resistor 22 is grounded.

[0054] The voltage divider module 2 in the present invention may include a first resistor 21 and a second resistor 22, which are voltage divider resistors. The input end of the first resistor 21 is connected to the first electrode of the first switch tube 1, and the output end of the first resistor 21 can be connected to the input end of the second resistor 22 and the input end of the signal processing module 3 respectively. The output end of the second resistor 22 is grounded, and the input voltage of the first electrode of the first switch tube 1 can be converted into a smaller first voltage signal through the first resistor 21 and the second resistor 22.

[0055] In one embodiment, the signal processing module 3 includes: a third resistor 31, a fourth resistor 32, a fifth resistor 33, a first operational amplifier 34 and a second operational amplifier 35; one end of the third resistor 31 is connected to the voltage divider module 2, and the other end of the third resistor 31 is respectively connected to one end of the fourth resistor 32 and the reverse input end of the first operational amplifier 34; the other end of the fourth resistor 32 is respectively connected to the output end of the first operational amplifier 34 and the same-direction input end of the second operational amplifier 35; one end of the fifth resistor 33 is connected to the same-direction input end of the first operational amplifier 34, and the other end of the fifth resistor 33 is grounded; the reverse input end of the second operational amplifier 35 is respectively connected to the output end of the second operational amplifier 35 and the driving module 4.

[0056] Specifically, the input end of the third resistor 31 in the present invention is connected to the voltage divider module 2, that is, the input end of the third resistor 31 is respectively connected to the output end of the first resistor 21 and the input end of the second resistor 22 in the voltage divider module 2, the output end of the third resistor 31 can be respectively connected to the input end of the fourth resistor 32 and the reverse input end of the first operational amplifier 34, the output end of the fourth resistor 32 can be respectively connected to the output end of the first operational amplifier 34 and the same-direction input end of the second operational amplifier 35, the input end of the fifth resistor 33 is connected to the same-direction input end of the first operational amplifier 34, the output end of the fifth resistor 33 is connected to the ground line, and the reverse input end of the second operational amplifier 35 can be respectively connected to the output end of the second operational amplifier 35 and the input end of the driving module 4. After receiving the first voltage signal input by the voltage divider module 2, the signal processing module 3 in the present invention can perform signal processing through the first operational amplifier 34, and enhance its driving ability through the second operational amplifier 35, so that it is converted into a second voltage signal, and the second voltage signal is input to the driving module 4.

[0057] The operational amplifier is a high-gain differential amplifier, which is widely used in signal amplification, filtering, comparison, integration, differentiation and other circuits. The operational amplifier has the characteristics of high input impedance, low output impedance and high gain, and is an important component in electronic circuit design. The working principle of the operational amplifier is based on differential amplification: Input signal: The operational amplifier has two input terminals, namely the non-inverting input terminal (V+) and the inverting input terminal (V-). Differential amplification: The operational amplifier amplifies the voltage difference between the two input terminals, and the output voltage (Vout) is proportional to the input voltage difference (V+-V-). High gain: The gain of the operational amplifier is very high, usually between hundreds of thousands and millions of times. The characteristics of the operational amplifier are: High input impedance: The input impedance of the operational amplifier is very high, usually in the megohm level, and almost no current is drawn from the input signal source. Low output impedance: The output impedance of the operational amplifier is very low, usually between a few ohms and tens of ohms, and can drive low impedance loads. High gain: The open-loop gain of the operational amplifier is very high, usually between hundreds of thousands and millions of times. Differential Input: An operational amplifier has two input terminals, one for the non-inverting input and one for the inverting input. Advantages of operational amplifiers are: High Gain: The gain of an operational amplifier is very high, which is suitable for signal amplification and processing. High Input Impedance: The input impedance of an operational amplifier is very high, and it draws almost no current from the input signal source. Low Output Impedance: The output impedance of an operational amplifier is very low, and it can drive low impedance loads. Flexibility: An operational amplifier can achieve a variety of functions such as amplification, filtering, comparison, etc. through different circuit configurations.

[0058] In one embodiment, the driving module 4 includes: a second switch tube 41, a sixth resistor 42, a seventh resistor 43, a first diode 44, a second diode 45 and a driving integrated circuit 46; the first electrode of the second switch tube 41 is connected to the signal processing module 3, the second electrode of the second switch tube 41 is connected to one end of the sixth resistor 42, and the third electrode of the second switch tube 41 is connected to the anode of the first diode 44; the other end of the sixth resistor 42 is respectively connected to the third electrode of the first switch tube 1 and one end of the seventh resistor 43; the other end of the seventh resistor 43 is connected to the cathode of the second diode 45, and the anode of the second diode 45 is respectively connected to the driving integrated circuit 46 and the cathode of the first diode 44.

[0059] Specifically, the driving module 4 of the present invention may include: a second switch tube 41, a sixth resistor 42, a seventh resistor 43, a first diode 44, a second diode 45 and a driving integrated circuit 46. The first electrode of the second switch tube 41 may be connected to the output end of the signal processing module 3, that is, the first electrode of the second switch tube 41 may be connected to the reverse input end of the second operational amplifier 35 and the output end of the second operational amplifier 35, the second electrode of the second switch tube 41 may be connected to the input end of the sixth resistor 42, the output end of the sixth resistor 42 may be connected to the third electrode of the first switch tube 1 and the output end of the seventh resistor 43, the third electrode of the second switch tube 41 may be connected to the anode of the first diode 44, the cathode of the first diode 44 may be connected to the driving integrated circuit 46 and the anode of the second diode 45, and the cathode of the second diode 45 may be connected to the input end of the seventh resistor 43. When the first electrode of the second switch tube 41 receives the second voltage signal input by the signal processing module 3, the second voltage signal may drive the first electrode of the second switch tube 41.

[0060] A diode is a basic semiconductor device with unidirectional conductivity. It allows current to flow in one direction and hardly conducts in the opposite direction. Diodes are widely used in circuits such as rectification, voltage regulation, protection, switching, and signal detection. A diode is a two-terminal device, including: Anode: the end where current flows in. Cathode: the end where current flows out. The working principle of a diode is based on the unidirectional conductivity of a PN junction. The working principle of a diode can be divided into two stages: Forward bias: When the anode voltage is higher than the cathode voltage, the PN junction is turned on and current flows from the anode to the cathode. The turn-on voltage is usually between 0.6V and 1.7V, depending on the type of diode. Reverse bias: When the anode voltage is lower than the cathode voltage, the PN junction is cut off and the current is almost zero. The reverse voltage can withstand a certain voltage, and when it exceeds the reverse breakdown voltage, the diode will be damaged. The characteristics of a diode are: Unidirectional conductivity: The diode only allows current to flow in one direction. Turn-on voltage: The minimum voltage required for the diode to turn on, usually between 0.6V and 1.7V. Reverse breakdown voltage: The maximum reverse voltage that a diode can withstand, exceeding this voltage will cause the diode to be damaged. Fast switching speed: The diode has a fast switching speed and is suitable for high-frequency applications.

[0061] In the present invention, the second switch tube 41 is a metal oxide semiconductor field effect transistor (MOSFET); the first electrode of the second switch tube 41 is a gate; the second electrode of the second switch tube 41 is a drain; and the third electrode of the switch tube is a source.

[0062] Metal oxide semiconductor field effect transistor is a semiconductor device widely used in electronic circuits, mainly used for switching and amplifying signals. Metal oxide semiconductor field effect transistor has the characteristics of high input impedance, low conduction loss and fast switching speed, and is widely used in power management, motor control, communication equipment and other fields. Metal oxide semiconductor field effect transistor is a three-terminal device, including: Gate (Gate, G): used to control the switching state of the device. Drain (Drain, D): connected to the high voltage end, current flows from the drain to the source. Source (Source, S): connected to the low voltage end, current flows from the drain to the source. The working principle of metal oxide semiconductor field effect transistor is based on the control of gate voltage, and the flow of current is controlled by adjusting the gate voltage. The working principle of metal oxide semiconductor field effect transistor can be divided into two stages: On state: When a positive voltage is applied to the gate, the electric field between the gate and the source attracts electrons to form a conductive channel. The conductive channel allows current to flow from the drain to the source. Off state: When the gate voltage decreases or becomes negative, the conductive channel disappears and the current stops flowing. The characteristics of MOSFET are: High input impedance: The input impedance between the gate and the source is very high, and the gate current is very small, which is suitable for high-frequency switching applications. Low conduction loss: The on-resistance is low and the conduction loss is small. Fast switching speed: The switching speed of MOSFET is fast, which is suitable for high-frequency applications. Simple drive: The gate drive circuit of MOSFET is relatively simple, which is suitable for low-cost applications. The advantages of MOSFET are: High efficiency: Low conduction loss and fast switching speed improve system efficiency. High reliability: Suitable for high-frequency and high-voltage environments, with a long service life. Flexibility: Suitable for a variety of electronic applications, from low power to high power.

[0063] In an embodiment of the present invention, the overvoltage protection circuit may further include: a power supply module 5, one end of the power supply module 5 is respectively connected to the first electrode of the first switch tube 1 and one end of the voltage divider module 2, and the other end of the power supply module 5 is connected to the second electrode of the first switch tube 1 and the ground wire.

[0064] Specifically, the output end of the power supply module 5 in the present invention can be connected to the first electrode of the first switch tube 1 and the input end of the voltage divider module 2 respectively, and the other end of the power supply module 5 can be connected to the second electrode of the first switch tube 1 and grounded at the same time. The power supply module 5 is used to supply power to the overvoltage module circuit.

[0065] In one embodiment, the power supply module 5 includes: a power supply 51, a capacitor 52, an inductor 53 and a third diode 54; one end of the power supply 51 is respectively connected to one end of the capacitor 52, one end of the inductor 53 and the cathode of the third diode 54; the other end of the power supply 51 is respectively connected to the other end of the capacitor 52, the second electrode of the first switch tube 1 and the ground wire; the other end of the inductor 53 is respectively connected to the anode of the third diode 54, the first electrode of the first switch tube 1 and one end of the voltage divider module 2.

[0066] Specifically, the power supply module 5 in the present invention may include: a power supply 51, a capacitor 52, an inductor 53 and a third diode 54. The output end of the power supply 51 may be connected to the input end of the capacitor 52, the input end of the inductor 53 and the cathode of the third diode 54 respectively, the output end of the power supply 51 may be connected to the output end of the capacitor 52, the second electrode of the first switch tube 1 and the ground wire respectively, the output end of the inductor 53 may be connected to the anode of the third diode 54, the first electrode of the first switch tube 1 and the input end of the voltage divider module 2 respectively, that is, the input end of the first resistor 21 in the voltage divider module 2 may be connected to the anode of the third diode 54 and the output end of the inductor 53 respectively.

[0067] In the present invention, the driving module is divided into two parts except for the driving integrated circuit, one part is for adjusting the opening speed, and the other part is for adjusting the closing speed. The two parts are separated by chain diodes and do not affect each other. The second voltage signal output by the signal processing module can drive the second switch tube in the closing part to make the second switch tube enter the variable resistance area. Then, according to the transfer characteristic curve of the second switch tube, when the second switch tube is in the variable resistance area, the larger the overvoltage signal, the smaller the Vgs of the second switch tube, the larger the on-resistance of the second switch tube, and the larger the overall off-resistance. Figure 3 , which is a schematic diagram of a transfer characteristic curve of a second switch tube provided by an embodiment of the present invention. Figure 3 i D is the current of the second electrode of the second switch tube, U GS(off) is the turn-off voltage point of the second switch tube, u GS is the voltage from the first electrode to the third electrode of the second switch tube.

[0068] In the present invention, the generation of overvoltage may be that the switch tube is turned off too fast during its turn-off period, resulting in an excessively large rate of change of the drain current of the switch tube, thereby inducing a large electromotive force at both ends of the stray inductance, and the expression of the electromotive force may be: E=L*di / dt, wherein E represents the electromotive force, L represents the inductance of the parasitic inductance, and di / dt represents the rate of change of the drain current of the switch tube. When the second switch tube of the overvoltage protection circuit of the present invention works in the variable resistance area, the on-resistance of the second switch tube is adjusted according to the degree of opening of the channel of the second switch tube, and the on-resistance of the second switch tube plus the sixth resistor is the resistance for adjusting the turn-off speed. The increase of the resistance for adjusting the turn-off speed will reduce the turn-off speed of the first switch tube, that is, reduce the rate of change of the drain current of the switch tube, and then reduce the induced electromotive force, thereby realizing voltage convergence. Second, since the second switch tube in the driving module works in the variable resistance area, it can linearly adjust its resistance, that is, linearly adjust, and adjust the resistance of the turn-off speed, thereby realizing linear, dynamic, and smooth overvoltage protection.

[0069] In an embodiment of the present invention, the voltage divider module can be replaced by any sampling module, that is, it only needs to output an overvoltage signal. The signal processing module can be replaced by a comparison circuit, which only needs to output a certain voltage to drive the switch tube in the driving module. The circuit for driving the second switch tube can be changed to a special driving integrated circuit for driving.

[0070] In an embodiment of the present invention, a first switch tube includes a first electrode, a second electrode and a third electrode; the first electrode is used to receive an input voltage; the second electrode is grounded; a voltage divider module, one end of the voltage divider module is connected to the first electrode of the first switch tube; a signal processing module, one end of the signal processing module is connected to the other end of the voltage divider module; a driving module, one end of the driving module is connected to the other end of the signal processing module, and the other end of the driving module is connected to the third electrode of the first switch tube; the signal processing module is used to collect a first voltage signal output by the voltage divider module, convert the first voltage signal into a second voltage signal, and input the second voltage signal to the driving module; the driving module is used to drive the third electrode of the first switch tube through the second voltage signal. An input voltage is received through the first electrode of the first switch tube, one end of the voltage divider module is connected to the first electrode of the first switch tube, the voltage divider module receives the input voltage and performs voltage division processing on the input voltage to obtain a first voltage signal, and inputs the first voltage signal to the signal processing module, one end of the signal processing module is connected to the other end of the voltage divider module, the signal processing module converts the first voltage signal into a second voltage signal, and inputs the second voltage signal to the driving module, one end of the driving module is connected to the other end of the signal processing module, and the other end of the driving module is connected to the third electrode of the first switch tube. Finally, the driving module drives the third electrode of the first switch tube through the second voltage signal, thereby performing overvoltage protection. At the same time, when performing overvoltage protection, there is no need for cooperation between the control system and the overvoltage judgment unit, which reduces the cost of implementing overvoltage protection and reduces the complexity of the overvoltage protection circuit.

[0071] An embodiment of the present invention further provides an electronic device, the electronic device comprising the overvoltage protection circuit as described in any one of the above.

[0072] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0073] It will be appreciated by those skilled in the art that the embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the embodiments of the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0074] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0075] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0076] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0077] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0078] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0079] The above is a detailed introduction to an overvoltage protection circuit and an electronic device provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An overvoltage protection circuit, characterized in that: include: A first switch tube includes a first electrode, a second electrode and a third electrode; The first electrode is used to receive an input voltage; The second electrode is connected to the ground; A voltage dividing module, one end of which is connected to the first electrode of the first switch tube; A signal processing module, one end of which is connected to the other end of the voltage dividing module; A driving module, one end of which is connected to the other end of the signal processing module, and the other end of which is connected to the third electrode of the first switch tube; The signal processing module is used to collect the first voltage signal output by the voltage dividing module, convert the first voltage signal into a second voltage signal, and input the second voltage signal to the driving module; The driving module is used to drive the third electrode of the first switch tube through the second voltage signal.

2. The overvoltage protection circuit according to claim 1, characterized in that: The voltage dividing module comprises: a first resistor and a second resistor; One end of the first resistor is connected to the first electrode of the first switch tube, and the other end of the first resistor is respectively connected to one end of the second resistor and the signal processing module; The other end of the second resistor is grounded.

3. The overvoltage protection circuit according to claim 1, characterized in that: The signal processing module includes: a third resistor, a fourth resistor, a fifth resistor, a first operational amplifier and a second operational amplifier; One end of the third resistor is connected to the voltage divider module, and the other end of the third resistor is respectively connected to one end of the fourth resistor and the inverting input end of the first operational amplifier; The other end of the fourth resistor is connected to the output end of the first operational amplifier and the non-inverting input end of the second operational amplifier respectively; One end of the fifth resistor is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the fifth resistor is grounded; The inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier and the driving module respectively.

4. The overvoltage protection circuit according to claim 1, characterized in that: The driving module includes: a second switch tube, a sixth resistor, a seventh resistor, a first diode, a second diode and a driving integrated circuit; The first electrode of the second switch tube is connected to the signal processing module, the second electrode of the second switch tube is connected to one end of the sixth resistor, and the third electrode of the second switch tube is connected to the anode of the first diode; The other end of the sixth resistor is respectively connected to the third electrode of the first switch tube and one end of the seventh resistor; The other end of the seventh resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to the driving integrated circuit and the cathode of the first diode respectively.

5. The overvoltage protection circuit according to claim 1, characterized in that: The overvoltage protection circuit further includes: A power supply module, one end of which is respectively connected to the first electrode of the first switch tube and one end of the voltage divider module, and the other end of which is connected to the second electrode of the first switch tube and a ground wire.

6. The overvoltage protection circuit according to claim 5, characterized in that: The power supply module includes: a power supply, a capacitor, an inductor and a third diode; One end of the power supply is respectively connected to one end of the capacitor, one end of the inductor and the cathode of the third diode; the other end of the power supply is respectively connected to the other end of the capacitor, the second electrode of the first switch tube and the ground wire; The other end of the inductor is respectively connected to the anode of the third diode, the first electrode of the first switch tube and one end of the voltage divider module.

7. The overvoltage protection circuit according to claim 1, characterized in that: The first switch tube is an insulated gate bipolar transistor; the first electrode of the first switch tube is a collector; the second electrode of the first switch tube is an emitter; and the third electrode of the first switch tube is a gate.

8. The overvoltage protection circuit according to claim 4, characterized in that: The second switch tube is a metal oxide semiconductor field effect transistor; the first electrode of the second switch tube is a gate; the second electrode of the second switch tube is a drain; and the third electrode of the switch tube is a source.

9. The overvoltage protection circuit according to claim 7, characterized in that: The insulated gate bipolar transistor is a damped insulated gate bipolar transistor.

10. An electronic device, characterized in that: The electronic device comprises an overvoltage protection circuit as claimed in claims 1-9.

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