Power supply under-voltage protection method, power supply voltage protection system and switching amplifier

Abstract

The application discloses a power supply under-voltage protection method, a power supply under-voltage protection system and a switching amplifier, and relates to the technical field of power supply under-voltage protection methods. The method comprises the following steps: acquiring the power supply voltage of a driving chip, the driving chip being used for driving an insulated gate bipolar transistor so that the insulated gate bipolar transistor is turned on; generating an interrupt signal when the power supply voltage of the driving chip is in an under-voltage state; controlling a control chip to output a first signal and a logic conversion chip to output a second signal based on the interrupt signal, the logic conversion chip being used for voltage conversion of the output signal of the driving chip, the voltage-converted output signal being input into the driving chip so that the driving chip drives the insulated gate bipolar transistor, and the first signal being used for controlling the logic conversion chip to output the second signal to the driving chip so that the insulated gate bipolar transistor stops working. The application solves the technical problem that the service life of the insulated gate bipolar transistor is reduced due to the fact that the driving circuit cannot be protected from under-voltage in the prior art.

Description

Technical Field

[0001] This invention relates to the field of electronic power technology, and more specifically, to a power supply undervoltage protection method, a power supply undervoltage protection system, and a switching amplifier. Background Technology

[0002] An IGBT (Insulated Gate Bipolar Transistor) is a composite semiconductor device composed of a transistor and a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor). For example, Figure 1 The IGBT module shown consists of multiple MOSFETs.

[0003] In high-power switching amplifiers, MOSFETs are among the most critical components, requiring comprehensive protection. MOSFET driver protection is of paramount importance. MOSFETs typically operate in a switching state, switching frequently between the cutoff and fully conducting regions. Because this switching process involves traversing the linear region, switching losses are incurred. If an undervoltage fault occurs in the MOSFET driver of the switching amplifier, the collector (C) and gate (G) of the MOSFET will not conduct completely, causing the MOSFET to operate in the linear region. This increases losses and temperature, ultimately leading to the MOSFET burning out and being damaged.

[0004] Figure 2 This illustrates a driving circuit for a conventional MOSFET, consisting of... Figure 2 It can be seen that this driving circuit consists of an MCU (Microcontroller Unit), a logic level conversion chip, a driver chip, and an IGBT module. Figure 2 In the process, the MCU sends a 3.3V PWM control signal, which is converted into a 5V control signal by a logic level conversion chip. The 5V PWM control signal is then output as a 15V drive signal by the driver chip to the gate of the MOSFET. When the drive signal is high, the collector and emitter are connected, and when the drive signal is low, the collector and emitter are not connected.

[0005] However, switching power supplies are susceptible to interference from various factors (such as input voltage fluctuations and abnormal device operating temperatures), and this drive circuit does not provide undervoltage protection, posing a significant risk. Figure 3 This illustrates the operating status of various components in a switching power supply when it receives interference. Figure 3In this circuit, the interrupt enable voltage of the logic converter chip is low, meaning the logic converter chip continuously converts the voltage of the PWM signal output by the MCU. When the supply voltage of the driver chip drops, the gate drive voltage VGE of the driver chip also drops, meaning the driver chip operates under low voltage conditions, causing problems such as increased power consumption, abnormal temperature, and damage / burnout of the IGBT module.

[0006] There is currently no effective solution to the above problems. Summary of the Invention

[0007] This invention provides a power supply undervoltage protection method, a power supply undervoltage protection system, and a switching amplifier, to at least solve the technical problem in the related art where the inability to provide undervoltage protection for the drive circuit leads to a reduction in the service life of the insulated gate bipolar transistor.

[0008] According to one aspect of the present invention, a power supply undervoltage protection method is provided, comprising: acquiring the power supply voltage of a driver chip, wherein the driver chip is used to drive an insulated-gate bipolar transistor (IGBT) to turn on the IGBT; generating an interrupt signal when the power supply voltage of the driver chip is in an undervoltage state; controlling a control chip to output a first signal based on the interrupt signal, and controlling a logic conversion chip connected to the control chip to output a second signal, wherein the logic conversion chip is used to perform voltage conversion on the output signal of the driver chip, and input the voltage-converted output signal to the driver chip to drive the IGBT, and the first signal is used to control the logic conversion chip to output the second signal to the driver chip to stop the IGBT from working.

[0009] Furthermore, the power supply undervoltage protection method also includes: after acquiring the power supply voltage of the driver chip, generating an enable signal when the power supply voltage of the driver chip is not in an undervoltage state; controlling the control chip to output a third signal based on the enable signal; controlling the logic conversion chip to perform voltage conversion on the third signal to obtain a converted third signal, wherein the converted third signal is used to control the driver chip to drive the insulated gate bipolar transistor to turn on the insulated gate bipolar transistor.

[0010] Furthermore, the power supply undervoltage protection method also includes: after obtaining the power supply voltage of the driver chip, performing voltage division processing on the power supply voltage to obtain a voltage-divided power supply voltage; obtaining a reference voltage, performing voltage reduction processing on the reference voltage to obtain a voltage-reduced reference voltage; performing voltage division processing on the voltage-reduced reference voltage to obtain a voltage-divided reference voltage; comparing the voltage-divided power supply voltage and the voltage-divided reference voltage to obtain a comparison result; and determining whether the power supply voltage of the driver chip is in an undervoltage state based on the comparison result.

[0011] Furthermore, the power supply undervoltage protection method also includes: determining that the power supply voltage of the driver chip is in an undervoltage state when the power supply voltage after voltage division is less than the reference voltage after voltage division; and determining that the power supply voltage of the driver chip is not in an undervoltage state when the power supply voltage after voltage division is greater than or equal to the reference voltage after voltage division.

[0012] According to another aspect of the present invention, a power supply undervoltage protection system is also provided, comprising: a driver chip connected to an insulated-gate bipolar transistor (IGBT) for driving the IGBT to turn on; a protection circuit connected to the power supply of the driver chip for acquiring the power supply voltage of the driver chip and outputting an interrupt signal when the power supply voltage of the driver chip is in an undervoltage state; a control chip connected to the protection circuit for outputting a first signal based on the interrupt signal, wherein the first signal is used to control a logic conversion chip to output a second signal to the driver chip to stop the IGBT from working; and a logic conversion chip connected to the control chip, the protection circuit, and the driver chip for outputting the second signal based on the interrupt signal and / or outputting the second signal based on the first signal.

[0013] Furthermore, the protection circuit includes: a first port connected to the power supply of the driver chip; a first voltage divider circuit connected to the first port for dividing the power supply voltage of the driver chip to obtain a divided power supply voltage; a second port connected to a reference power supply; a second voltage divider circuit connected to the second port for dividing the reference voltage of the reference power supply to obtain a divided reference voltage; and a comparator connected to the first and second voltage divider circuits for comparing the divided power supply voltage with the divided reference voltage and outputting the comparison result.

[0014] Furthermore, the first voltage divider circuit includes: a first resistor, wherein a first end of the first resistor is connected to ground and a second end of the first resistor is connected to a first input port of the comparator; and a second resistor, wherein a first end of the second resistor is connected to the first port and a second end of the second resistor is connected to the first input port.

[0015] Furthermore, the protection circuit also includes a voltage regulator circuit connected between the second port and the second voltage divider circuit, used to step down the reference voltage of the reference power supply.

[0016] Furthermore, the second voltage divider circuit includes: a third resistor, wherein the first end of the third resistor is connected to the voltage regulator circuit and the second end of the third resistor is connected to the second input port of the comparator; and a fourth resistor, wherein the first end of the fourth resistor is connected to the ground wire and the second end of the fourth resistor is connected to the second input port.

[0017] Furthermore, the voltage regulator circuit includes: a voltage regulator connected between the reference power supply and the third resistor, used to step down the reference voltage of the reference power supply; a first capacitor connected to the input port of the voltage regulator, used to filter the reference voltage of the reference power supply; and a second capacitor connected to the output port of the voltage regulator, used to filter the output voltage of the voltage regulator.

[0018] Furthermore, the protection circuit also includes a coupling unit connected to the comparator, used to output an interrupt signal when the comparison result meets a preset condition.

[0019] Furthermore, the coupling unit includes: an optocoupler unit, wherein the negative terminal of the optocoupler unit is connected to the output port of the comparator, and the positive terminal of the optocoupler unit is connected to the current-limiting resistor; and a third voltage divider circuit, connected to the output port of the optocoupler unit, for dividing the output voltage of the optocoupler unit.

[0020] Furthermore, the coupling unit includes a fifth resistor, which is connected to the output port of the comparator and is used to control the switching of the coupling unit.

[0021] According to another aspect of the present invention, a switching amplifier is also provided, including the power supply undervoltage protection system of any one of the above.

[0022] In this embodiment of the invention, a combination of software and hardware is used to protect the insulated-gate bipolar transistor (IGBT). After obtaining the power supply voltage of the driver chip, it is detected whether the power supply voltage of the driver chip is undervoltage. If the power supply voltage of the driver chip is undervoltage, an interrupt signal is generated. Based on the interrupt signal, the control chip is controlled to output a first signal, and the logic conversion chip connected to the control chip is controlled to output a second signal. The driver chip is used to drive the IGBT to turn it on. The logic conversion chip is used to convert the output signal of the driver chip into voltage and input the converted output signal into the driver chip to drive the IGBT. The first signal is used to control the logic conversion chip to output the second signal to the driver chip to stop the IGBT from working.

[0023] In the above process, when the power supply voltage of the driver chip is undervoltage, the control chip can send a control command (i.e., a first signal) to the logic conversion chip, causing the logic conversion chip to output a second signal to the driver chip. This second signal causes the gate drive voltage of the driver chip to drop, thereby stopping the insulated-gate bipolar transistor (IGBT) from working. This process achieves software protection against IGBT drive power supply undervoltage. Alternatively, when the power supply voltage of the driver chip is undervoltage, the logic conversion chip can also directly output a second signal to the driver chip based on an interrupt signal. This means the protection circuit can directly control the logic conversion chip, thus achieving hardware protection against IGBT drive power supply undervoltage. In other words, this application employs a combination of software and hardware protection, avoiding the problem of insufficient drive voltage causing the IGBT to fail to fully conduct, leading to a reduced lifespan of the IGBT. This improves the performance of the IGBT, reduces MOSFET losses, and alleviates IGBT overheating, ultimately extending the lifespan of the IGBT.

[0024] Therefore, the solution provided in this application achieves the purpose of protecting the insulated gate bipolar transistor when the power supply voltage of the driver chip is undervoltage, thereby improving the service life of the insulated gate bipolar transistor and solving the technical problem in related technologies where the service life of the insulated gate bipolar transistor is reduced due to the inability to provide undervoltage protection for the driver circuit. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0026] Figure 1 This is a schematic diagram of an IGBT module in the prior art;

[0027] Figure 2 It is a traditional MOSFET drive circuit;

[0028] Figure 3 It is a waveform diagram of the working state of each component in the existing drive circuit;

[0029] Figure 4 This is a flowchart of a power supply undervoltage protection method according to an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of an optional power supply undervoltage protection system according to an embodiment of the present invention;

[0031] Figure 6 This is an output waveform diagram of an optional component according to an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of an optional protection circuit according to an embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of an optional electronic device according to an embodiment of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] It should be noted that all relevant information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for display, data used for analysis, etc.) involved in this invention are information and data authorized by the user or fully authorized by all parties. For example, this system has an interface with the relevant user or organization. Before obtaining relevant information, it needs to send an acquisition request to the aforementioned user or organization through the interface, and obtain the relevant information after receiving consent from the aforementioned user or organization.

[0037] Example 1

[0038] According to an embodiment of the present invention, a power supply undervoltage protection method embodiment is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0039] Figure 4 This is a flowchart of an optional power supply undervoltage protection method according to an embodiment of the present invention, such as... Figure 4 As shown, the method includes the following steps:

[0040] Step S402: Obtain the power supply voltage of the driver chip, wherein the driver chip is used to drive the insulated gate bipolar transistor to turn on the insulated gate bipolar transistor.

[0041] In step S402, the driver chip is connected to the insulated gate bipolar transistor (IGBT), wherein the driver chip can control the conduction of the IGBT.

[0042] Optional, Figure 5 A schematic diagram of an optional power supply undervoltage protection system is shown, consisting of... Figure 5 As can be seen, this system adds a protection circuit compared to existing technologies. This protection circuit is connected to the drive power supply of the driver chip and can control the control chip MCU and logic conversion chip when the power supply voltage of the driver chip is insufficient, thereby protecting the IGBT module.

[0043] Step S404: When the power supply voltage of the driver chip is undervoltage, an interrupt signal is generated.

[0044] In step S404, in this embodiment, when the power supply voltage of the driver chip is lower than 15V, the power supply voltage of the driver chip is in an undervoltage state. The protection circuit includes a comparator, which determines whether the power supply voltage of the driver chip is in an undervoltage state and generates an interrupt signal to interrupt the operation of the IGBT module when the power supply voltage of the driver chip is in an undervoltage state.

[0045] Step S406: Based on the interrupt signal, the control chip outputs a first signal and controls the logic conversion chip connected to the control chip to output a second signal. The logic conversion chip is used to perform voltage conversion on the output signal of the driver chip and input the voltage-converted output signal into the driver chip so that the driver chip drives the insulated gate bipolar transistor. The first signal is used to control the logic conversion chip to output the second signal to the driver chip so that the insulated gate bipolar transistor stops working.

[0046] Optional, Figure 6 The output waveforms of each component under the protection circuit are shown, such as... Figure 6As shown, after the protection circuit generates an interrupt signal, it simultaneously sends the interrupt signal to both the control chip (MCU) and the logic converter chip. This means the protection circuit can directly control the logic converter chip to interrupt its PWM signal output. Specifically, when the interrupt enable voltage of the logic converter chip is high, the logic converter chip stops voltage conversion and only outputs a low level, causing the gate drive voltage of the driver chip to drop and the IGBT module to stop working, thus achieving hardware protection against power supply undervoltage. Additionally, the protection circuit can also control the control chip (MCU) to output a first signal. Since the control chip (MCU) is connected to the logic converter chip, the control chip (MCU) uses this first signal to control the logic converter chip to interrupt its PWM signal output, achieving software protection against power supply undervoltage.

[0047] Based on the scheme defined in steps S402 to S406 above, it can be understood that in this embodiment of the invention, a method combining software and hardware is used to protect the insulated-gate bipolar transistor (IGBT). After obtaining the power supply voltage of the driver chip, it is detected whether the power supply voltage of the driver chip is in an undervoltage state. When the power supply voltage of the driver chip is in an undervoltage state, an interrupt signal is generated, and based on the interrupt signal, the control chip is controlled to output a first signal, and the logic conversion chip connected to the control chip is controlled to output a second signal. The driver chip is used to drive the IGBT to turn it on, and the logic conversion chip is used to perform voltage conversion on the output signal of the driver chip and input the voltage-converted output signal into the driver chip to drive the IGBT. The first signal is used to control the logic conversion chip to output the second signal to the driver chip to stop the IGBT from working.

[0048] It is noteworthy that in the above process, when the power supply voltage of the driver chip is undervoltage, the control chip can send a control command (i.e., a first signal) to the logic conversion chip, causing the logic conversion chip to output a second signal to the driver chip. This second signal causes the gate drive voltage of the driver chip to drop, thereby stopping the insulated-gate bipolar transistor (IGBT) from operating. This process achieves software protection against IGBT drive power supply undervoltage. Furthermore, when the power supply voltage of the driver chip is undervoltage, the logic conversion chip can also directly output a second signal to the driver chip based on an interrupt signal. This means the protection circuit can directly control the logic conversion chip, thus achieving hardware protection against IGBT drive power supply undervoltage. In other words, this application employs a combination of software and hardware protection, avoiding the problem of insufficient drive voltage causing the IGBT to fail to fully conduct, leading to a reduced lifespan of the IGBT. This improves the performance of the IGBT, reduces MOSFET losses, and alleviates IGBT overheating, ultimately extending the IGBT's lifespan.

[0049] Therefore, the solution provided in this application achieves the purpose of protecting the insulated gate bipolar transistor when the power supply voltage of the driver chip is undervoltage, thereby improving the service life of the insulated gate bipolar transistor and solving the technical problem in related technologies where the service life of the insulated gate bipolar transistor is reduced due to the inability to provide undervoltage protection for the driver circuit.

[0050] In one optional embodiment, after obtaining the power supply voltage of the driver chip, if the power supply voltage of the driver chip is not in an undervoltage state, the protection circuit generates an enable signal and controls the control chip to output a third signal based on the enable signal. Then, the control logic conversion chip performs voltage conversion on the third signal to obtain the converted third signal, wherein the converted third signal is used to control the driver chip to drive the insulated gate bipolar transistor to turn on the insulated gate bipolar transistor.

[0051] When the power supply voltage of the driver chip is sufficient, the protection circuit outputs an enable signal to the control chip MCU and the logic conversion chip, so that the control chip MCU and the logic conversion chip can output PWM signals normally, so that the driver chip can drive the insulated gate bipolar transistor.

[0052] In one optional embodiment, after acquiring the power supply voltage of the driver chip, the protection circuit performs voltage division processing on the power supply voltage to obtain a voltage-divided power supply voltage. Then, it acquires a reference voltage, performs voltage reduction processing on the reference voltage to obtain a voltage-reduced reference voltage, and performs voltage division processing on the voltage-reduced reference voltage to obtain a voltage-divided reference voltage. The voltage-divided power supply voltage and the voltage-divided reference voltage are compared to obtain a comparison result, and the power supply voltage of the driver chip is determined to be in an undervoltage state based on the comparison result.

[0053] Optional, Figure 7 A schematic diagram of an optional protection circuit is shown, such as... Figure 7 As shown, the reference voltage is converted from 15V to 5V by a voltage regulator W. Then, it passes through a voltage divider circuit composed of resistors R3 and R4 to obtain the divided reference voltage V-. That is, the divided reference voltage V- can be expressed by the following formula:

[0054]

[0055] It should be noted that, to ensure the reference voltage V- after voltage division remains unaffected when the power supply voltage drops, the reference voltage is regulated by the voltage regulator W from the 15V supply voltage. The voltage regulator model can be, but is not limited to, 7805. The 7805 voltage regulator has a maximum input voltage limit of 36V and a minimum input voltage of 7V. Within this voltage range, the regulator can stably output 5V.

[0056] In addition, the power supply voltage V1 of the driver chip is divided into a voltage divider circuit composed of resistors R1 and R2 to obtain the divided power supply voltage V+, which can be expressed by the following formula:

[0057]

[0058] Furthermore, such as Figure 7 As shown, after obtaining the power supply voltage and the reference voltage after voltage division, the comparator P compares the two voltages and outputs the comparison result Vout.

[0059] Specifically, if the power supply voltage after voltage division is lower than the reference voltage after voltage division, it is determined that the power supply voltage of the driver chip is in an undervoltage state, and Vout outputs a high level. If the power supply voltage after voltage division is greater than or equal to the reference voltage after voltage division, it is determined that the power supply voltage of the driver chip is not in an undervoltage state, and Vout outputs a low level.

[0060] When Vout is low, the LED of coupling unit U is turned on, and the transistor of coupling unit U is turned on, and the output port FO of the protection circuit is high; when Vout is high, the LED of coupling unit U is not turned on, and the transistor of coupling unit U is not turned on, and the output port FO of the protection circuit is low.

[0061] The output port FO of the protection circuit is connected to the OE pin (i.e., the interrupt enable port) of the logic conversion chip. When the OE pin is high, the logic conversion chip interrupts the output of the PWM signal; when the OE pin is low, the logic conversion chip outputs the PWM signal normally. The output port FO of the protection circuit is also connected to the control chip MCU. When the interrupt enable port of the control chip MCU is high, the control chip MCU interrupts the output of the PWM signal; when the interrupt enable port of the control chip MCU is low, the control chip MCU outputs the PWM signal normally.

[0062] Only when the power supply voltage of the driver chip returns to normal, that is, when V+ > V-, will the comparator output Vout be high, and the PWM control signal will be sent normally, and the IGBT will start working again.

[0063] As can be seen from the above, this application employs a protection circuit to achieve dual hardware and software protection against undervoltage of the IGBT drive power supply. This involves sending an interrupt signal to both the logic conversion chip (hardware) and the control chip MCU (software), with both chips terminating the PWM wave transmission. This prevents damage caused by accidental IGBT turn-on, avoiding the problem in related technologies where insufficient drive voltage prevents the IGBT from fully turning on. It improves IGBT performance, reduces MOSFET losses and IGBT module overheating, extends IGBT lifespan, and ensures comprehensive protection for the high-power switching amplifier during use.

[0064] Example 2

[0065] According to an embodiment of the present invention, an embodiment of a power supply undervoltage protection system is also provided, wherein, Figure 5 This is a schematic diagram of an optional power undervoltage protection system according to an embodiment of the present invention, such as... Figure 5 As shown, the system includes: a control chip (i.e., MCU) 10, a logic conversion chip 20, a driver chip 30, an insulated gate bipolar transistor (i.e., IGBT module) 40, and a protection circuit 50.

[0066] like Figure 5 As shown, the driver chip 30 is connected to the insulated-gate bipolar transistor 40 and is used to drive the insulated-gate bipolar transistor 40 to turn it on; the protection circuit 50 is connected to the power supply of the driver chip 30 and is used to obtain the power supply voltage of the driver chip 30, and output an interrupt signal when the power supply voltage of the driver chip 30 is undervoltage; the control chip 10 is connected to the protection circuit 50 and is used to output a first signal based on the interrupt signal, wherein the first signal is used to control the logic conversion chip 20 to output a second signal to the driver chip 30 to stop the insulated-gate bipolar transistor 40 from working; the logic conversion chip 20 is connected to the control chip 10, the protection circuit 50 and the driver chip 30, and is used to output a second signal based on the interrupt signal and / or output a second signal based on the first signal.

[0067] It should be noted that, as shown in point 5, this system adds a protection circuit compared to existing technologies. This protection circuit is connected to the drive chip's power supply and can control the MCU and logic conversion chip when the drive chip's power supply voltage is insufficient, thereby protecting the IGBT module.

[0068] In addition, in this embodiment, when the power supply voltage of the driver chip is lower than 15V, the power supply voltage of the driver chip is in an undervoltage state. A comparator is deployed in the protection circuit to determine whether the power supply voltage of the driver chip is in an undervoltage state, and generates an interrupt signal to interrupt the operation of the IGBT module when the power supply voltage of the driver chip is in an undervoltage state.

[0069] Optional, Figure 6 The output waveforms of each component under the protection circuit are shown, such as... Figure 6 As shown, after the protection circuit generates an interrupt signal, it simultaneously sends the interrupt signal to both the control chip (MCU) and the logic converter chip. This means the protection circuit can directly control the logic converter chip to interrupt its PWM signal output. Specifically, when the interrupt enable voltage of the logic converter chip is high, the logic converter chip stops voltage conversion and only outputs a low level, causing the gate drive voltage of the driver chip to drop and the IGBT module to stop working, thus achieving hardware protection against power supply undervoltage. Additionally, the protection circuit can also control the control chip (MCU) to output a first signal. Since the control chip (MCU) is connected to the logic converter chip, the control chip (MCU) uses this first signal to control the logic converter chip to interrupt its PWM signal output, achieving software protection against power supply undervoltage.

[0070] As described above, in this embodiment, when the power supply voltage of the driver chip is undervoltage, the control chip can send a control command (i.e., a first signal) to the logic conversion chip, causing the logic conversion chip to output a second signal to the driver chip. This second signal causes the gate drive voltage of the driver chip to drop, thereby stopping the insulated-gate bipolar transistor (IGBT) from working. This process achieves software protection against IGBT drive power supply undervoltage. Furthermore, when the power supply voltage of the driver chip is undervoltage, the logic conversion chip can also directly output a second signal to the driver chip based on an interrupt signal. This means the protection circuit can directly control the logic conversion chip, thus achieving hardware protection against IGBT drive power supply undervoltage. In other words, this application employs a combination of software and hardware protection, avoiding the problem of insufficient drive voltage causing the IGBT to fail to fully conduct, leading to a reduced lifespan of the IGBT. This improves the performance of the IGBT, reduces MOSFET losses, and alleviates IGBT overheating, thereby extending the lifespan of the IGBT.

[0071] Therefore, the solution provided in this application achieves the purpose of protecting the insulated gate bipolar transistor when the power supply voltage of the driver chip is undervoltage, thereby improving the service life of the insulated gate bipolar transistor and solving the technical problem in related technologies where the service life of the insulated gate bipolar transistor is reduced due to the inability to provide undervoltage protection for the driver circuit.

[0072] In one alternative embodiment, Figure 7 A schematic diagram of an optional protection circuit is shown, such as... Figure 7 As shown, the protection circuit includes: a first port M1, a first voltage divider circuit L1, a second port M2, a second voltage divider circuit L2, and a comparator P.

[0073] The first port M1 is connected to the power supply V1 of the driver chip 30; the first voltage divider circuit L1 is connected to the first port M1 and is used to divide the power supply voltage of the driver chip 30 to obtain the divided power supply voltage.

[0074] The second port M2 is connected to the reference power supply V2; the second voltage divider circuit L2 is connected to the second port M2 and is used to divide the reference voltage of the reference power supply V2 to obtain the divided reference voltage.

[0075] Comparator P is connected to the first voltage divider circuit L1 and the second voltage divider circuit L2. It is used to compare the divided power supply voltage with the divided reference voltage and output the comparison result.

[0076] It should be noted that the reference power supply voltage can be, but is not limited to, 15V, and other voltage values ​​can be set according to actual needs.

[0077] Furthermore, the first voltage divider circuit L1 can be composed of multiple resistors, for example, in Figure 7 In the circuit, the first voltage divider circuit includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to ground, and the second end of the first resistor R1 is connected to the first input port of the comparator P. The first end of the second resistor R2 is connected to the first input port, and the second end of the second resistor R2 is connected to the first input port.

[0078] That is, the power supply voltage V1 of the driver chip is divided into a voltage divider circuit composed of resistors R1 and R2 to obtain the voltage divider voltage V+. The voltage divider voltage can be expressed by the following formula:

[0079]

[0080] It should be noted that the values ​​of the first resistor R1 and the second resistor R2 can also be set according to actual needs, and this application does not impose specific limitations on their values.

[0081] In an optional embodiment, the protection circuit 50 further includes a voltage regulator circuit T, wherein the voltage regulator circuit T is connected between the second port M2 and the second voltage divider circuit L2, and is used to step down the reference voltage of the reference power supply V2.

[0082] like Figure 7 As shown, the second voltage divider circuit L2 includes: a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected to the voltage regulator circuit T, and the second end of the third resistor R3 is connected to the second input port of the comparator P. The first end of the fourth resistor R4 is connected to the ground wire, and the second end of the fourth resistor R4 is connected to the second input port.

[0083] The voltage regulator circuit T includes: a voltage regulator T, a first capacitor C1, and a second capacitor C2. The voltage regulator T is connected between the reference power supply and the third resistor R3, and is used to step down the reference voltage of the reference power supply. The first capacitor C1 is connected to the input port of the voltage regulator T, and is used to filter the reference voltage of the reference power supply. The second capacitor C2 is connected to the output port of the voltage regulator T, and is used to filter the output voltage of the voltage regulator T.

[0084] Optional, in Figure 7 In the process, the reference voltage is converted by the voltage regulator W, reducing the 15V reference voltage to 5V. Then, it passes through a voltage divider circuit composed of resistors R3 and R4 to obtain the divided reference voltage V-. That is, the divided reference voltage V- can be expressed by the following formula:

[0085]

[0086] It should be noted that, to ensure the reference voltage V- after voltage division remains unaffected when the power supply voltage drops, the reference voltage is regulated by the voltage regulator W from the 15V supply voltage. The voltage regulator model can be, but is not limited to, 7805. The 7805 voltage regulator has a maximum input voltage limit of 36V and a minimum input voltage of 7V. Within this voltage range, the regulator can stably output 5V.

[0087] In one alternative embodiment, such as Figure 7 As shown, the protection circuit 50 further includes a coupling unit U, wherein the coupling unit U is connected to the comparator P and is used to output an interrupt signal when the comparison result meets the preset conditions.

[0088] Optionally, the coupling unit U includes: an optocoupler unit, a third voltage divider circuit L3, and a fifth resistor R5. The negative terminal of the optocoupler unit is connected to the output port of the comparator P, and the positive terminal of the optocoupler unit is connected to the current-limiting resistor R8. The third voltage divider circuit L3 is connected to the output port of the optocoupler unit and is used to divide the output voltage of the optocoupler unit. The fifth resistor R5 is connected to the output port of the comparator P and is used to control the switching of the coupling unit.

[0089] It should be noted that, by Figure 7 It can be seen that the third voltage divider circuit L3 consists of resistors R6 and R7. Resistor R5 is a pull-up resistor, which ensures that the optocoupler unit is in the off state when there is no output Vout. In addition, the optocoupler unit can achieve signal isolation between 5V and 3.3V voltages.

[0090] Furthermore, the specific values ​​of the capacitors C1 and C2, and the resistors R5, R6, R7, and R8 mentioned above are not specifically limited in this application.

[0091] Furthermore, such as Figure 7 As shown, after obtaining the power supply voltage and the reference voltage after voltage division, the comparator P compares the two voltages and outputs the comparison result Vout.

[0092] Specifically, if the power supply voltage after voltage division is lower than the reference voltage after voltage division, it is determined that the power supply voltage of the driver chip is in an undervoltage state, and Vout outputs a high level. If the power supply voltage after voltage division is greater than or equal to the reference voltage after voltage division, it is determined that the power supply voltage of the driver chip is not in an undervoltage state, and Vout outputs a low level.

[0093] When Vout is low, the LED of coupling unit U is turned on, and the transistor of coupling unit U is turned on, and the output port FO of the protection circuit is high; when Vout is high, the LED of coupling unit U is not turned on, and the transistor of coupling unit U is not turned on, and the output port FO of the protection circuit is low.

[0094] The output port FO of the protection circuit is connected to the OE pin (i.e., the interrupt enable port) of the logic conversion chip. When the OE pin is high, the logic conversion chip interrupts the output of the PWM signal; when the OE pin is low, the logic conversion chip outputs the PWM signal normally. The output port FO of the protection circuit is also connected to the control chip MCU. When the interrupt enable port of the control chip MCU is high, the control chip MCU interrupts the output of the PWM signal; when the interrupt enable port of the control chip MCU is low, the control chip MCU outputs the PWM signal normally.

[0095] Only when the power supply voltage of the driver chip returns to normal, that is, when V+ > V-, will the comparator output Vout be high, and the PWM control signal will be sent normally, and the IGBT will start working again.

[0096] As can be seen from the above, this application employs a protection circuit to achieve dual hardware and software protection against undervoltage of the IGBT drive power supply. This involves sending an interrupt signal to both the logic conversion chip (hardware) and the control chip MCU (software), with both chips terminating the PWM wave transmission. This prevents damage caused by accidental IGBT turn-on, avoiding the problem in related technologies where insufficient drive voltage prevents the IGBT from fully turning on. It improves IGBT performance, reduces MOSFET losses and IGBT module overheating, extends IGBT lifespan, and ensures comprehensive protection for the high-power switching amplifier during use.

[0097] Example 3

[0098] According to another aspect of the present invention, a switching amplifier is also provided, which includes the power supply undervoltage protection system described in the above embodiments.

[0099] Example 4

[0100] According to another aspect of the present invention, an electronic device is also provided, wherein, Figure 8 This is a schematic diagram of an optional electronic device according to an embodiment of the present invention, such as... Figure 8 As shown, the electronic device includes one or more processors; and a memory for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to run the programs, wherein the programs are configured to execute the aforementioned storage resource allocation method during runtime.

[0101] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0102] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0103] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0104] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0105] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0106] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0107] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of under-voltage protection of a power supply, characterized by, The method comprises the following steps: obtaining a power supply voltage of a driving chip, wherein the driving chip is used to drive an insulated gate bipolar transistor to turn on the insulated gate bipolar transistor; generating an interrupt signal when the power supply voltage of the driving chip is in an under-voltage state; controlling a control chip to output a first signal based on the interrupt signal, and controlling a logic conversion chip connected with the control chip to output a second signal, wherein the logic conversion chip is used to perform voltage conversion on an output signal of the driving chip, and input the voltage-converted output signal into the driving chip, so that the driving chip drives the insulated gate bipolar transistor, and the first signal is used to control the logic conversion chip to output the second signal to the driving chip, so that the insulated gate bipolar transistor stops working.

2. The method of claim 1, wherein, After obtaining the power supply voltage of the driving chip, the method further comprises the following steps: generating an enable signal when the power supply voltage of the driving chip is not in the under-voltage state; controlling the control chip to output a third signal based on the enable signal; controlling the logic conversion chip to perform voltage conversion on the third signal to obtain a converted third signal, wherein the converted third signal is used to control the driving chip to drive the insulated gate bipolar transistor to turn on the insulated gate bipolar transistor.

3. The method of claim 1, wherein, After obtaining the power supply voltage of the driving chip, the method further comprises the following steps: performing voltage division on the power supply voltage to obtain a divided power supply voltage; obtaining a reference voltage, performing voltage reduction on the reference voltage to obtain a reduced reference voltage; performing voltage division on the reduced reference voltage to obtain a divided reference voltage; comparing the divided power supply voltage and the divided reference voltage to obtain a comparison result; determining whether the power supply voltage of the driving chip is in the under-voltage state according to the comparison result.

4. The method of claim 3, wherein, Determining whether the power supply voltage of the driving chip is in the under-voltage state according to the comparison result comprises the following steps: determining that the power supply voltage of the driving chip is in the under-voltage state when the divided power supply voltage is less than the divided reference voltage; determining that the power supply voltage of the driving chip is not in the under-voltage state when the divided power supply voltage is greater than or equal to the divided reference voltage.

5. A power supply under-voltage protection system, characterized by, The method comprises the following steps: a driving chip connected with an insulated gate bipolar transistor, used to drive the insulated gate bipolar transistor to turn on the insulated gate bipolar transistor; a protection circuit connected with a power supply of the driving chip, used to obtain a power supply voltage of the driving chip, and output an interrupt signal when the power supply voltage of the driving chip is in an under-voltage state; a control chip connected with the protection circuit, used to output a first signal based on the interrupt signal, wherein the first signal is used to control a logic conversion chip to output a second signal to the driving chip, so that the insulated gate bipolar transistor stops working; the logic conversion chip is connected with the control chip, the protection circuit and the driving chip, and is used to output the second signal based on the interrupt signal, and / or output the second signal based on the first signal.

6. The system of claim 5, wherein, The protection circuit comprises: a first port connected to a power supply of the driving chip; a first voltage dividing circuit connected to the first port, configured to divide a voltage of the power supply of the driving chip to obtain a divided voltage of the power supply; a second port connected to a reference power supply; a second voltage dividing circuit connected to the second port, configured to divide a reference voltage of the reference power supply to obtain a divided reference voltage; a comparator connected to the first voltage dividing circuit and the second voltage dividing circuit, configured to compare the divided voltage of the power supply with the divided reference voltage and output a comparison result.

7. The system of claim 6, wherein, The first voltage dividing circuit comprises: a first resistor, wherein a first end of the first resistor is connected to a ground wire, and a second end of the first resistor is connected to a first input port of the comparator; a second resistor, wherein a first end of the second resistor is connected to the first port, and a second end of the second resistor is connected to the first input port.

8. The system of claim 6, wherein, The protection circuit further comprises: a voltage stabilizing circuit connected between the second port and the second voltage dividing circuit, configured to step down the reference voltage of the reference power supply.

9. The system of claim 8, wherein, The second voltage dividing circuit comprises: a third resistor, wherein a first end of the third resistor is connected to the voltage stabilizing circuit, and a second end of the third resistor is connected to a second input port of the comparator; a fourth resistor, wherein a first end of the fourth resistor is connected to a ground wire, and a second end of the fourth resistor is connected to the second input port.

10. The system of claim 9, wherein, The voltage stabilizing circuit comprises: a voltage stabilizer connected between the reference power supply and the third resistor, configured to step down the reference voltage of the reference power supply; a first capacitor connected to an input port of the voltage stabilizer, configured to filter the reference voltage of the reference power supply; a second capacitor connected to an output port of the voltage stabilizer, configured to filter an output voltage of the voltage stabilizer.

11. A switching amplifier, characterized by The power supply under-voltage protection system comprises the protection circuit according to any one of claims 5 to 10.

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