Driving protection circuit, gate driving chip and equipment

Abstract

The invention provides a driving protection circuit, a gate driving chip and equipment, and the driving protection circuit comprises a temperature detection circuit which is configured to output a first temperature detection signal when the temperature is greater than or equal to a preset temperature, and output a second temperature detection signal when the temperature is lower than the preset temperature; the first end of the overvoltage protection circuit is connected with the power supply voltage, the second end of the overvoltage protection circuit is grounded, the third end of the overvoltage protection circuit is connected with the output end of the temperature detection circuit, and the overvoltage protection circuit is configured to pull down the power supply voltage when receiving the first temperature detection signal and pull down the power supply voltage when receiving the second temperature detection signal. And the power supply voltage remains unchanged. The temperature detection circuit provides the first temperature detection signal or the second temperature detection signal for the overvoltage protection circuit according to the temperature change, so that the overvoltage protection circuit can adjust the power supply voltage along with the temperature to reduce the risk of circuit damage caused by the increase of the power supply voltage or the high temperature.

Description

Technical Field

[0001] The present application relates to the technical field of gate drive integrated circuits, and more specifically to a drive protection circuit, a gate drive chip and a device. Background Art

[0002] With the rapid development of power electronics technology, the application of drive circuits is becoming more and more extensive, and gate drive chips play an important role in driving power devices. However, when the gate drive chip is in a high temperature environment and accompanied by large noise (i.e., large current), the power supply voltage will be raised, thereby damaging the related circuits connected to the power supply voltage and affecting the stability of the product. Summary of the invention

[0003] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0004] In view of the existing problems, the present invention provides a driving protection circuit on one hand, and the driving protection circuit includes:

[0005] A temperature detection circuit, wherein the temperature detection circuit is configured to output a first temperature detection signal when the temperature is greater than or equal to a preset temperature, and output a second temperature detection signal when the temperature is lower than the preset temperature;

[0006] An overvoltage protection circuit, wherein a first end of the overvoltage protection circuit is connected to a power supply voltage, a second end of the overvoltage protection circuit is grounded, and a third end of the overvoltage protection circuit is connected to an output end of the temperature detection circuit, wherein the overvoltage protection circuit is configured to lower the power supply voltage when the third end of the overvoltage protection circuit receives the first temperature detection signal or when the power supply voltage is higher than a predetermined voltage, and when the third end of the overvoltage protection circuit receives the second temperature detection signal, the power supply voltage remains unchanged.

[0007] The above technical solution has the following advantages or beneficial effects: the temperature detection circuit provides a corresponding temperature detection signal (i.e., a first temperature detection signal or a second temperature detection signal) to the overvoltage protection circuit according to the change in temperature, so that the overvoltage protection circuit can adjust the power supply voltage according to the temperature, thereby better protecting the circuits connected to the power supply voltage, such as the gate drive circuit, and the chip load in a high temperature environment, reducing the risk of large current caused by power supply voltage fluctuations at high temperatures and damage to related circuits caused by increased power supply voltage.

[0008] Exemplarily, the overvoltage protection circuit includes:

[0009] A voltage divider circuit, one end of which is connected to the power supply voltage and the other end is grounded;

[0010] a first switch circuit, the first switch circuit being electrically connected to the output end of the voltage divider circuit and the temperature detection circuit, and being configured to: be turned on when receiving the first temperature detection signal so that the voltage divider node of the voltage divider circuit outputs a first voltage signal, and be turned off when receiving the second temperature detection signal so that the voltage divider node of the voltage divider circuit outputs a second voltage signal;

[0011] an inverting circuit, wherein a first end of the inverting circuit is connected to the power supply voltage, a second end of the inverting circuit is grounded, a signal input end of the inverting circuit is connected to the voltage dividing node, and is configured to invert the first voltage signal to output a third voltage signal, and invert the second voltage signal to output a fourth voltage signal;

[0012] A second switch circuit, a first end of which is connected to the power supply voltage, a second end of which is grounded, and a third end of which is connected to the output end of the inverter circuit, is configured to: turn on when receiving the third voltage signal to lower the power supply voltage, and turn off when receiving the fourth voltage signal to keep the power supply voltage unchanged.

[0013] The above technical solution has the following advantages or beneficial effects: the output signal of the temperature detection circuit is accessed through the first switching circuit, and the first switching circuit is connected to the voltage divider circuit to transmit the temperature state represented by the output signal of the temperature detection circuit to the input end of the inverter circuit, and inverted through the inverter circuit, thereby ensuring that the switching state of the second switching circuit can correctly reflect the voltage state (that is, whether the voltage exceeds the power supply voltage or is in a high temperature state), so as to protect the relevant circuits in a high temperature environment or when overvoltage occurs to avoid damage to them.

[0014] Exemplarily, the voltage-dividing circuit includes a plurality of voltage-dividing diodes and at least one voltage-dividing resistor connected in series, wherein the first switching circuit includes an NMOS tube, the NMOS tube is connected in parallel to at least one of the voltage-dividing diodes or the NMOS tube is connected in parallel to at least one of the voltage-dividing resistors or the NMOS tube is connected in parallel to at least one of the voltage-dividing diodes and at least one of the voltage-dividing resistors, and the control end of the NMOS tube is connected to the output end of the temperature detection circuit.

[0015] The above technical solution has the following advantages or beneficial effects: the power supply voltage is divided by a voltage-dividing diode or a voltage-dividing resistor, and then connected in parallel to the voltage-dividing circuit through the first switch circuit, so that when the first switch circuit is not conducting, the parallel-connected voltage-dividing diode or voltage-dividing resistor is short-circuited, and the current in the voltage-dividing circuit increases, so that the voltage connected to the overvoltage protection circuit increases, thereby lowering the power supply voltage in the subsequent overvoltage protection circuit.

[0016] Exemplarily, the first node of the voltage divider circuit is connected to the source of the NMOS tube, the voltage divider node is located between the first node and the ground terminal of the voltage divider circuit, and at least one voltage divider diode and / or at least one voltage divider resistor are connected in series between the voltage divider node and the ground terminal of the voltage divider circuit.

[0017] The above technical solution has the following advantages or beneficial effects: by limiting the position of the voltage-dividing node, the voltage-dividing node can effectively reflect the temperature state represented by the temperature detection signal connected to the voltage-dividing circuit.

[0018] Exemplarily, the inverting circuit includes: an odd number of inverters connected in sequence to invert an input signal of the inverting circuit.

[0019] The above technical solution has the following advantages or beneficial effects: an odd number of inverters can make the voltage signal output by the voltage divider circuit opposite to the voltage signal input by the second switch circuit, thereby matching the control end signal of the second switch circuit with that of the first switch circuit to correctly characterize the temperature state detected by the temperature detection circuit.

[0020] Exemplarily, the second switch circuit includes a PMOS tube, a control end of the PMOS tube is connected to the output end of the inverter circuit, a source of the PMOS tube is connected to a power supply voltage, and a drain of the PMOS tube is grounded.

[0021] The above technical solution has the following advantages or beneficial effects: according to the conduction characteristics of the PMOS tube, the PMOS tube is selected as the device in the second switch circuit, and cooperates with the first switch circuit to complete the coordination of the temperature detection circuit and the overvoltage protection circuit, so as to protect the subsequent gate drive circuit and other related circuits.

[0022] Exemplarily, the temperature detection circuit includes a comparator, a negative input terminal of the comparator is connected to a reference signal, a positive input terminal of the comparator is connected to a detected temperature signal, and an output terminal of the comparator is connected to a third terminal of the overvoltage protection circuit.

[0023] The above technical solution has the following advantages or beneficial effects: by comparing the reference signal with the temperature signal to be detected, a first temperature detection signal or a second temperature detection signal representing the temperature state is obtained, and then the first temperature detection signal or the second temperature detection signal is applied to the subsequent overvoltage protection circuit to protect the related circuits.

[0024] On the other hand, the present application provides a gate driving chip, the gate driving chip comprising: the driving protection circuit as described above;

[0025] The gate driving circuit, the power supply voltage is connected to the gate driving circuit via the driving protection circuit.

[0026] The above technical solution has the following advantages or beneficial effects: the power supply voltage is input to the gate drive circuit after passing through the drive protection circuit. Since the drive protection circuit will lower the power supply voltage when the temperature is high or the power supply voltage increases, it protects the gate drive circuit to prevent the gate drive circuit from being damaged due to the increase in the power supply voltage, thereby causing instability of related devices.

[0027] Exemplarily, the gate driving chip further includes a bandgap reference circuit, which is used to provide a reference signal to the temperature detection circuit and the gate driving circuit;

[0028] The logic control circuit is used to provide a control signal to the gate drive circuit so that the gate drive circuit drives the chip load.

[0029] The above technical solution has the following advantages or beneficial effects: a reference signal is provided by a bandgap reference circuit so that the temperature detection circuit and the gate drive circuit have a reference comparison object, and the functions of the relevant circuits can be realized; and the gate drive circuit realizes its function through the control signal provided by the logic control circuit.

[0030] On the other hand, the present application provides a device, which includes the gate driving chip as described above.

[0031] The above technical solution has the following advantages or beneficial effects: since the device includes a gate driving chip, and the gate driving chip includes a driving protection circuit, the device can also obtain the corresponding beneficial effects of the driving protection circuit.

[0032] According to the drive protection circuit, gate drive chip and device provided in the present application, the temperature detection circuit provides a corresponding temperature detection signal (i.e., a first temperature detection signal or a second temperature detection signal) to the overvoltage protection circuit according to the change in temperature, so that the overvoltage protection circuit can adjust the power supply voltage according to the temperature, and thus can better protect the circuit connected to the power supply voltage, such as the gate drive circuit, and the chip load in a high temperature environment, thereby reducing the risk of large current caused by power supply voltage fluctuations at high temperatures and the risk of damage to related circuits when the power supply voltage increases, thereby improving the stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0034] Figure 1 A schematic structural block diagram showing a driving protection circuit according to a specific embodiment of the present invention;

[0035] Figure 2 A schematic circuit diagram showing a temperature detection circuit in a driving protection circuit according to a specific embodiment of the present invention;

[0036] Figure 3 A schematic circuit diagram showing an overvoltage protection circuit in a driving protection circuit according to a specific embodiment of the present invention;

[0037] Figure 4 A schematic block diagram showing a gate driving chip according to a specific embodiment of the present invention;

[0038] Figure 5 A schematic block diagram of a device according to a specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0040] With the rapid development of power electronics technology, gate drive chips are increasingly used in power electronic devices. Gate drive chips play a key role in motor control. In related technologies, the input signal is amplified after passing through the gate drive circuit to generate current to drive the load power device. The power supply voltage of the gate drive chip is identified by the undervoltage protection circuit. Only when the power supply voltage of the gate drive chip reaches its normal working voltage, the signal of the gate drive chip can be transmitted normally to avoid damage to the power electronic equipment or unstable operation due to insufficient power supply. The undervoltage protection circuit can avoid the influence of insufficient power supply voltage on power electronic equipment, and when the power supply voltage is higher than the normal working voltage, it will also damage the power electronic equipment. For example, in a high temperature environment, it is easy to cause the power supply voltage to jump, and the power supply voltage jump will cause a large current. The large current may cause the circuit module of the gate drive chip to be damaged and unable to generate the correct drive signal normally, thereby affecting the stability of the gate drive chip load.

[0041] Based on the above technical problems, the embodiments of the present application provide a driving protection circuit, a gate driving chip and a device to reduce the power supply voltage when the power supply voltage increases in a high temperature environment, thereby protecting the gate driving chip and the load of the gate driving chip. The present application is described in detail below.

[0042] First, refer to Figure 1-Figure 2 A driving protection circuit according to some embodiments of the present application.

[0043] like Figure 1 As shown, the driving protection circuit 100 includes: a temperature detection circuit 110 and an overvoltage protection circuit 120 .

[0044] Furthermore, the temperature detection circuit 110 is configured to output a first temperature detection signal when the temperature is greater than or equal to a preset temperature, and to output a second temperature detection signal when the temperature is lower than the preset temperature.

[0045] In some embodiments, the temperature detection circuit includes a comparator, a negative input terminal of the comparator is connected to a reference signal, a positive input terminal of the comparator is connected to a detected temperature signal, and an output terminal of the comparator is connected to a third terminal of the overvoltage protection circuit.

[0046] For example, Figure 2As shown, the negative input terminal of the comparator is connected to the reference signal VREF, which is a voltage signal that does not change with temperature. The positive input terminal of the comparator receives the detection temperature signal VTEMP, which is a voltage signal that is proportional to the temperature. The reference signal VREF is compared with the temperature signal VTEMP to be detected to generate the output signal EN1 of the temperature detection circuit 110. For example, when the output signal EN1 is at a low level, it indicates that the current temperature is lower than or equal to the preset temperature. When the output signal EN1 is at a high level, it indicates that the current temperature is higher than the preset temperature. That is, when the temperature detection circuit 110 outputs the first temperature detection signal, the output signal EN1 is at a high level. When the temperature detection circuit 110 outputs the second temperature detection signal, the output signal EN1 is at a low level. By outputting different temperature detection signals, the circuit connected to the output terminal of the temperature detection circuit can perform adaptive actions based on the temperature detection signal.

[0047] A first terminal of the overvoltage protection circuit 120 is connected to the power supply voltage VCC, a second terminal of the overvoltage protection circuit 120 is grounded (not shown), and a third terminal of the overvoltage protection circuit 120 is connected to the output terminal of the temperature detection circuit 110, wherein the overvoltage protection circuit 120 is configured to pull down the power supply voltage when the third terminal of the overvoltage protection circuit 120 receives a first temperature detection signal or when the power supply voltage is higher than a predetermined voltage (for example, a path between the power supply voltage and the ground terminal is turned on, so that the power supply voltage is directly grounded, and almost no power is supplied to a load that needs power and is connected to the power supply voltage, thereby protecting the load); when the third terminal of the overvoltage protection circuit 120 receives a second temperature detection signal, the power supply voltage remains unchanged so that the power supply voltage can supply power to its load normally.

[0048] In some embodiments, the overvoltage protection circuit includes: a voltage divider circuit, one end of the voltage divider circuit is connected to the power supply voltage, and the other end is grounded. Figure 3 As shown, in one example, the voltage divider circuit 1201 includes 6 voltage divider diodes D (D represents Figure 3 The voltage divider circuit 1201 includes any one of D1, D2, D3, D4, D5, and D6) and three voltage divider resistors R, and the power supply voltage VCC connected to the voltage divider circuit 1201 is divided by the voltage divider diodes D and the voltage divider resistors R. It is worth mentioning that the number of the above-mentioned voltage divider diodes and voltage divider resistors is only for example, and more or less voltage divider diodes and / or voltage divider resistors can be used according to actual needs.

[0049] In some embodiments, the overvoltage protection circuit includes a first switching circuit, which is electrically connected to the output end of the voltage divider circuit and the temperature detection circuit, and is configured to: turn on when a first temperature detection signal is received so that the voltage divider node of the voltage divider circuit outputs a first voltage signal; and turn off when a second temperature detection signal is received so that the voltage divider node of the voltage divider circuit outputs a second voltage signal.

[0050] In some embodiments, the voltage divider circuit includes multiple voltage divider diodes and at least one voltage divider resistor connected in series, wherein the first switching circuit includes an NMOS tube, the NMOS tube is connected in parallel with at least one voltage divider diode or the NMOS tube is connected in parallel with at least one voltage divider resistor or the NMOS tube is connected in parallel with at least one voltage divider diode and at least one voltage divider resistor, and the control end of the NMOS tube is connected to the output end of the temperature detection circuit.

[0051] The NMOS transistor Q1 is connected in parallel with some of the voltage-dividing diodes D and / or the voltage-dividing resistors R in the voltage-dividing circuit 1201. For example, the NMOS transistor Q1 is connected in parallel with two voltage-dividing diodes D (voltage-dividing diode D1 and voltage-dividing diode D2). The resistance value of the voltage-dividing resistor in the voltage-dividing circuit 1201 is controlled by turning on and off the NMOS transistor Q1 to adjust the voltage value output by the voltage-dividing node in the voltage-dividing circuit 1201. In some embodiments, the number of the voltage-dividing diodes connected in parallel with the NMOS transistor Q1 can be reasonably adjusted according to actual needs, which can be one or more than three, or the NMOS transistor can be connected in parallel with at least one voltage-dividing diode and / or at least one voltage-dividing resistor in the voltage-dividing circuit. In other embodiments, the first switch circuit can also include one or more switch transistors, such as NMOS transistors or PMOS transistors, and are respectively connected in parallel with at least one voltage-dividing diode and / or at least one voltage-dividing resistor to adjust the resistance value of the voltage-dividing circuit according to the temperature, thereby adjusting the circuit and the voltage value output by the voltage-dividing node of the voltage-dividing circuit.

[0052] In some embodiments, the first node of the voltage divider circuit is connected to the source of the NMOS tube, the voltage divider node is located between the first node and the ground terminal of the voltage divider circuit, and at least one voltage divider diode and / or at least one voltage divider resistor are connected in series between the voltage divider node and the ground terminal of the voltage divider circuit.

[0053] Continue as Figure 3As shown, the NMOS tube is connected in parallel with a voltage-dividing diode D2 and a voltage-dividing diode D3, wherein the drain of the NMOS tube Q1 is connected between the voltage-dividing diode D1 and the voltage-dividing diode D2, and the source of the NMOS tube Q1 is connected between the voltage-dividing diode D3 and the voltage-dividing diode D4. The connection point between the source of the NMOS tube Q1 and the voltage-dividing circuit 1201 is the first node, and the voltage-dividing node is located between the first node and the ground end of the voltage-dividing circuit. The voltage-dividing magnitude at the voltage-dividing node is related to the current of the voltage-dividing circuit 1201 and the voltage-dividing diode or voltage-dividing resistor connected in series between the voltage-dividing node and the ground end of the voltage-dividing circuit. For example, the voltage-dividing node is set between the voltage-dividing diode D4 and the voltage-dividing diode D5, and the voltage-dividing diode D5 and the voltage-dividing diode D6 are connected in series between the voltage-dividing node and the ground end of the voltage-dividing circuit 1201. Then, the voltage-dividing voltage at the voltage-dividing node is equal to the current of the voltage-dividing circuit 1201 multiplied by the sum of the resistance values ​​of the voltage-dividing diode D5 and the voltage-dividing diode D6. The circuit of the voltage divider circuit 1201 is related to the total resistance value on the voltage divider circuit 1201. Therefore, the total resistance value on the voltage divider circuit 1201 is controlled by turning on and off the NMOS tube Q1. The NMOS tube Q1 is connected in parallel with the voltage divider diodes D2 and D3. When a high level is input to the control end of the NMOS tube Q1, the NMOS tube Q1 is turned on. That is, when the output signal of the temperature detection circuit 110 is the first temperature detection signal, the NMOS tube Q1 is turned on. At this time, the voltage divider diodes D1 and D2 connected in parallel with the NMOS tube Q1 are short-circuited. Then, the total resistance value on the voltage divider circuit 1201 is approximately equal to the resistance value of the three voltage divider resistors and the voltage divider diodes D1, D4, D5, and D6. The sum of the resistance values, when the power supply voltage VCC remains unchanged, according to the relationship between current, voltage and resistance, the current of the voltage divider circuit 1201 will increase. Therefore, the voltage output from the voltage divider node will increase, that is, the voltage signal EN2 output by the voltage divider circuit 1201 increases. At this time, the voltage signal EN2 output by the voltage divider circuit 1201 is the first voltage signal; similarly, when the control end of the NMOS tube Q1 inputs a low level, the NMOS tube Q1 is turned off, that is, when the output signal of the temperature detection circuit 110 is the second temperature detection signal, the NMOS tube Q1 is turned off, the resistance on the voltage divider circuit 1201 remains unchanged, and the voltage output from the voltage divider node remains almost unchanged. At this time, the voltage signal EN2 output by the voltage divider circuit 1201 is the second voltage signal. It is worth mentioning that when the NMOS tube Q1 is turned off, the resistance on the voltage divider circuit 1201 remains unchanged. If other reasons cause the power supply voltage VCC input to the voltage divider circuit to increase, for example, the power supply voltage VCC is changed from 3V to 5V, at this time, due to the increase in voltage, when the resistance in the voltage divider circuit 1201 remains unchanged, the current of the voltage divider circuit 1201 will also increase, and its divided voltage will also increase. At this time, the voltage signal EN2 output by the voltage divider circuit 1201 is the first voltage signal.

[0054] In some embodiments, the overvoltage protection circuit includes an inverting circuit, a first end of the inverting circuit is connected to a power supply voltage, a second end of the inverting circuit is grounded, a signal input end of the inverting circuit is connected to a voltage dividing node, and is configured to invert the first voltage signal to output a third voltage signal, and to invert the second voltage signal to output a fourth voltage signal.

[0055] Exemplarily, the first switch circuit controls the resistance of the resistor in the voltage divider circuit by turning on and off the NMOS tube to control the output signal of the voltage divider node of the voltage divider circuit, and the output signal of the voltage divider node is opposite to the output signal of the inverting circuit. For example, the voltage divider circuit outputs the first voltage signal or the second voltage signal to the inverting circuit through the voltage divider node after voltage division by the voltage divider diode and / or the voltage divider resistor. Exemplarily, as Figure 3 As shown, the inversion circuit 1203 includes an odd number of inverters INV connected in sequence to invert the input signal. If an even number of inverters INV is used, the input signal remains unchanged after passing through the inversion circuit 1203. Using multiple inverters INV for inversion can make the signal output from the inversion circuit 1203 more stable.

[0056] In a specific embodiment, Figure 1-Figure 3 As shown, when the temperature is greater than or equal to the preset temperature, the reference signal VREF is compared with the temperature signal to be detected VTEMP input into the comparator to generate a high-level first temperature detection signal, that is, the output signal EN1 of the temperature detection circuit 110 is high, and the high level is connected to the NMOS tube Q1 to make it turned on, the voltage-dividing diode D2 and the voltage-dividing diode D3 of the voltage-dividing circuit 1201 are short-circuited, and the voltage outputted by the voltage-dividing node of the voltage-dividing circuit 1201 is increased compared with before the NMOS tube Q1 is turned on. At this time, the voltage-dividing node outputs a first voltage signal of a high level, and the first voltage signal is inverted by the three inverters INV of the inverting circuit 1203 and then outputs a third voltage signal of a low level, that is, the inverted voltage signal EN3 is a low level, and the low-level signal is transmitted to the control end of the PMOS tube Q2 to turn on the PMOS tube Q2, thereby pulling down the power supply voltage VCC.

[0057] In some embodiments, the overvoltage protection circuit includes a second switch circuit, a first end of which is connected to the power supply voltage, a second end is grounded, and a third end of the second switch circuit is connected to the output end of the inverter circuit, and is configured to: turn on when a third voltage signal is received to lower the power supply voltage, and turn off when a fourth voltage signal is received to keep the power supply voltage unchanged. For example, the output signal of the voltage-dividing node of the voltage-dividing circuit is opposite to the input signal of the control end of the second switch circuit, and when the power supply voltage increases or the voltage signal output by the voltage-dividing circuit is the first voltage signal due to an increase in temperature, the second switch circuit needs to be turned on to lower the power supply voltage. Therefore, in some embodiments, the second switch circuit includes a PMOS tube, the control end of the PMOS tube is connected to the output end of the inverter circuit, the source of the PMOS tube is connected to the power supply voltage, and the drain of the PMOS tube is grounded. Figure 3 As shown, the second switch circuit 1204 includes a PMOS transistor Q2. When the PMOS transistor Q2 is turned on, the power supply voltage VCC is short-circuited with the ground, thereby pulling down the power supply voltage VCC.

[0058] will specifically combine Figure 3 The working principle and process of the overvoltage protection circuit in the embodiment of the present application are described. The overvoltage protection circuit 120 includes a first switch circuit 1202, a voltage divider circuit 1201, an inverter circuit 1203 and a second switch circuit 1204 connected in sequence. The input voltage of the voltage divider circuit 1201 is the power supply voltage VCC. The first end of the first switch circuit 1202 is connected to the output signal EN1 of the temperature detection circuit. The second end and the third end of the first switch circuit 1202 are connected to the voltage divider circuit 1201. The voltage divided by the voltage divider circuit 1201 is controlled by turning on and off the first switch circuit 1202, and the voltage signal EN2 is output to the inverter circuit 1203 through the voltage divider node. After the voltage signal EN2 is inverted by the inverter circuit 1203, the inverted voltage signal EN3 is output. The inverted voltage signal EN3 is finally connected to the first end of the second switch circuit 1204 to control the turning on and off of the second switch circuit 1204. Figure 3It can be seen that when the second switch circuit 1204 is turned on, the power supply voltage VCC is short-circuited with the ground, so that the power supply voltage VCC is pulled down. When the second switch circuit 1204 is turned off, the power supply voltage VCC will not be directly connected to the ground, and the power supply voltage VCC will not be affected and remain unchanged. Since the third terminal of the overvoltage protection circuit 120 is connected to the output terminal of the temperature detection circuit 110, and the output signal EN1 of the temperature detection circuit 110 is the first temperature detection signal or the second temperature detection signal, the first switch circuit 1202, the inverter circuit 1203 and the second switch circuit 1204 need to be configured to perform different operations according to different input signals, so that when the power supply voltage increases or the temperature is high, the second switch circuit 1204 is turned on to pull down the power supply voltage, and at normal temperature, the second switch circuit 1204 is turned off and the power supply voltage remains unchanged. The specific configuration is as follows: for the first switch circuit 1202, when the first temperature detection signal is received, it is turned on so that the voltage dividing node of the voltage dividing circuit 1201 outputs the first voltage signal to the inverter circuit 1203, and when the second temperature detection signal is received, it is turned off so that the voltage dividing node of the voltage dividing circuit 1201 outputs the second voltage signal to the inverter circuit 1203; the inverter circuit 1203 inverts the first voltage signal to output a third voltage signal, and inverts the second voltage signal to output a fourth voltage signal; for the second switch circuit 1204, when the third voltage signal is received, it is turned on to lower the power supply voltage VCC, and when the fourth voltage signal is received, it is turned off to keep the power supply voltage VCC unchanged.

[0059] It is worth mentioning that each circuit in the embodiments of the present application may include more or fewer electronic components while maintaining normal functions.

[0060] According to the driving protection circuit provided in the present application, the temperature detection circuit provides a corresponding temperature detection signal (i.e., a first temperature detection signal or a second temperature detection signal) to the overvoltage protection circuit according to the change of temperature, so that the overvoltage protection circuit can adjust the power supply voltage according to the temperature, and thus can better protect the circuit connected to the power supply voltage in a high temperature environment, such as the gate drive circuit, and the chip load, thereby reducing the risk of large current caused by power supply voltage fluctuations at high temperatures and the risk of damage to related circuits when the power supply voltage increases, thereby improving the stability of the product.

[0061] Another aspect of the present application provides a gate driver chip, the gate driver chip comprising: the above-mentioned drive protection circuit; the gate driver circuit, the power supply voltage is connected to the gate driver circuit via the drive protection circuit. In some embodiments, the gate driver chip also includes a bandgap reference circuit for providing a reference signal to the temperature detection circuit and the gate driver circuit; and a logic control circuit for providing a control signal to the gate driver circuit so that the gate driver circuit drives the chip load.

[0062] like Figure 4 As shown, the driving protection circuit 100 inputs the power supply voltage VCC and the temperature signal VTEMP to be detected, the bandgap reference circuit 320 provides the reference signal VREF to the driving protection circuit 100, and the driving protection circuit 100 processes according to the reference signal VREF and the temperature signal VTEMP to be detected. At room temperature, the driving protection circuit 100 outputs the power supply voltage VCC to the gate driving circuit 310. At this time, the gate driving circuit 310 works normally under the control signal provided by the logic control circuit 330 and the reference signal provided by the bandgap reference circuit 320, and outputs the driving signal OUT to the load of the gate driving chip 300 to drive the load to work. At high temperature or when the power supply voltage VCC increases (i.e., overvoltage), the driving protection circuit 100 outputs the lowered power supply voltage VCC. The lowered power supply voltage VCC cannot ensure the normal operation of the gate driving circuit 310, and therefore cannot provide a normal driving signal to the load to drive the chip load. Therefore, at high temperature or overvoltage, the gate driving circuit 310 can be prevented from being damaged, thereby preventing the load of the gate driving chip 300 from being damaged. The logic control circuit 330 includes an input module, a filter delay circuit, and an undervoltage protection module. The signal output by the input module, such as a clock signal, is filtered by the filter delay circuit and then transmitted to the logic control module. The logic control module generates a control signal based on the received signal and transmits it to the gate drive circuit 310. The undervoltage protection circuit is used to identify the power supply voltage VCC of the gate drive chip 300. Only when the power supply voltage VCC of the gate drive chip reaches its normal working voltage, the signal of the gate drive chip VCC can be transmitted normally to avoid damage to the power electronic equipment or unstable operation due to insufficient power supply. The gate drive chip 300 also includes a low voltage difference linear regulator LDO to adjust the stability of the input reference signal VREF. It is worth mentioning that the specific process of the drive protection circuit 100 processing according to the reference signal VREF and the temperature signal to be detected VTEMP has been specifically described in the drive protection circuit 100, which will not be repeated here.

[0063] In some embodiments, the chip load includes power switching devices, such as MOSFETs and IGBTs.

[0064] In another aspect of this application, Figure 5As shown, a device 400 is provided, the device 400 includes the above gate drive chip 300 and a device to be driven (i.e., a chip load), the output end of the gate drive chip is electrically connected to the control end of the device to be driven, for example, when the device to be driven is an IGBT, the gate of the IGBT is connected, the device may include household appliances, such as electric fans, air conditioners, kitchen hoods, high-speed air ducts, washing machines, etc., and the semiconductor module can be used in the motor drive system of household appliances. The electronic device can also be a new energy vehicle, industrial automation equipment, switching power supply, etc., or it can be an intermediate product with the above-mentioned gate drive circuit, for example: an intelligent power module with the gate drive circuit, etc., or the device 400 can also be a transportation equipment such as a vehicle.

[0065] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present application may be implemented with the aid of hardware including several different elements and with the aid of appropriately programmed computers. In a unit claim listing several on-board systems, several of these on-board systems may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names.

[0066] The above is only a specific implementation method or description of a specific implementation method of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A driving protection circuit, characterized in that: The driving protection circuit comprises: A temperature detection circuit, wherein the temperature detection circuit is configured to output a first temperature detection signal when the temperature is greater than or equal to a preset temperature, and output a second temperature detection signal when the temperature is lower than the preset temperature; An overvoltage protection circuit, wherein a first end of the overvoltage protection circuit is connected to a power supply voltage, a second end of the overvoltage protection circuit is grounded, and a third end of the overvoltage protection circuit is connected to an output end of the temperature detection circuit, wherein the overvoltage protection circuit is configured to lower the power supply voltage when the third end of the overvoltage protection circuit receives the first temperature detection signal or when the power supply voltage is higher than a predetermined voltage, and when the third end of the overvoltage protection circuit receives the second temperature detection signal, the power supply voltage remains unchanged.

2. The driving protection circuit according to claim 1, characterized in that: The overvoltage protection circuit comprises: A voltage divider circuit, one end of which is connected to the power supply voltage and the other end is grounded; a first switch circuit, the first switch circuit being electrically connected to the output end of the voltage divider circuit and the temperature detection circuit, and being configured to: be turned on when receiving the first temperature detection signal so that the voltage divider node of the voltage divider circuit outputs a first voltage signal, and be turned off when receiving the second temperature detection signal so that the voltage divider node of the voltage divider circuit outputs a second voltage signal; an inverting circuit, wherein a first end of the inverting circuit is connected to the power supply voltage, a second end of the inverting circuit is grounded, a signal input end of the inverting circuit is connected to the voltage dividing node, and is configured to invert the first voltage signal to output a third voltage signal, and invert the second voltage signal to output a fourth voltage signal; A second switch circuit, a first end of which is connected to the power supply voltage, a second end of which is grounded, and a third end of which is connected to the output end of the inverter circuit, is configured to: turn on when receiving the third voltage signal to lower the power supply voltage, and turn off when receiving the fourth voltage signal to keep the power supply voltage unchanged.

3. The driving protection circuit according to claim 2, characterized in that: The voltage divider circuit includes a plurality of voltage divider diodes and at least one voltage divider resistor connected in series, wherein: The first switching circuit includes an NMOS tube, the NMOS tube is connected in parallel to at least one of the voltage-dividing diodes or the NMOS tube is connected in parallel to at least one of the voltage-dividing resistors or the NMOS tube is connected in parallel to at least one of the voltage-dividing diodes and at least one of the voltage-dividing resistors, and the control end of the NMOS tube is connected to the output end of the temperature detection circuit.

4. The driving protection circuit according to claim 3, characterized in that: The first node of the voltage divider circuit is connected to the source of the NMOS tube, the voltage divider node is located between the first node and the ground terminal of the voltage divider circuit, and at least one voltage divider diode and / or at least one voltage divider resistor are connected in series between the voltage divider node and the ground terminal of the voltage divider circuit.

5. The driving protection circuit according to claim 2, characterized in that: The inverting circuit comprises an odd number of inverters connected in sequence to invert an input signal of the inverting circuit.

6. The driving protection circuit according to claim 2, characterized in that: The second switch circuit includes a PMOS tube, a control end of the PMOS tube is connected to the output end of the inverter circuit, a source of the PMOS tube is connected to a power supply voltage, and a drain of the PMOS tube is grounded.

7. The driving protection circuit according to claim 1, characterized in that: The temperature detection circuit comprises a comparator, a negative input terminal of the comparator is connected to a reference signal, a positive input terminal of the comparator is connected to a detected temperature signal, and an output terminal of the comparator is connected to a third terminal of the overvoltage protection circuit.

8. A gate driver chip, characterized in that: include: The driving protection circuit according to any one of claims 1 to 7; The gate driving circuit, the power supply voltage is connected to the gate driving circuit via the driving protection circuit.

9. The gate driving chip according to claim 8, characterized in that: Also includes: A bandgap reference circuit, used for providing a reference signal to the temperature detection circuit and the gate drive circuit; The logic control circuit is used to provide a control signal to the gate drive circuit so that the gate drive circuit drives the chip load.

10. A device, characterized in that: The device comprises a gate driver chip as described in any one of claims 8 to 9.

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