Over-current protection circuit, gate driving chip and electronic equipment

Abstract

The invention provides an overcurrent protection circuit, a gate driving chip and electronic equipment. The overcurrent protection circuit comprises a temperature detection circuit which is used for detecting the environment temperature of a target circuit and outputting a temperature detection voltage signal; the output end of the temperature detection circuit is connected with the control end of the threshold voltage adjustment circuit, and the threshold voltage adjustment circuit is used for outputting a threshold voltage signal based on the temperature detection voltage signal; the output end of the threshold voltage adjusting circuit is connected with the first input end of the overcurrent protection circuit, and the overcurrent protection circuit is used for obtaining the threshold voltage signal and generating an overcurrent protection signal based on the overcurrent detection signal and the threshold voltage signal of the target circuit. According to the over-current protection circuit, the threshold value of the over-current protection circuit is adjusted through the temperature detection circuit, so that a circuit module of a target circuit can be prevented from being damaged by large current generated on the power side at high temperature, and meanwhile, related loads of the target circuit can be better protected.

Description

Technical Field

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

[0002] The gate driver chip plays a key role in motor control. It amplifies the output signal of the microcontroller unit (MCU) to generate current to drive the load power device, such as the insulated gate bipolar transistor (IGBT) and the metal-oxide semiconductor field-effect transistor (MOSFET), to drive the power device on and off. At the same time, it also isolates the MCU from the drive circuit to protect the normal operation of the MCU.

[0003] The gate drive chip usually includes an overcurrent protection circuit. The overcurrent protection circuit controls the conduction of the chip by feeding back the current generated by the power side through a sampling resistor to the chip side. When the current is greater than the set value, the gate drive chip output is turned off and the load module stops working.

[0004] When the current setting value in the overcurrent protection circuit is determined, the large current generated on the power side under high temperature conditions can easily damage the load module and the driver chip. Therefore, how to better protect the chip and the load in a high temperature environment has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The present application is proposed in view of the above problems. The present application provides an overcurrent protection circuit, a gate drive chip and an electronic device, which can prevent the large current generated on the power side from damaging the circuit module of the target circuit at high temperature, and can also better protect the related loads of the target circuit.

[0006] According to a first aspect of the present application, an overcurrent protection circuit is provided, the overcurrent protection circuit comprising:

[0007] A temperature detection circuit is used to detect the ambient temperature of the target circuit and output a temperature detection voltage signal;

[0008] a threshold voltage adjustment circuit, wherein the output end of the temperature detection circuit is connected to the control end of the threshold voltage adjustment circuit, and is used to output a threshold voltage signal based on the temperature detection voltage signal, wherein when the ambient temperature exceeds a threshold temperature range, the threshold voltage signal is a first voltage signal, and when the ambient temperature is within the threshold temperature range, the threshold voltage signal is a second voltage signal, and a voltage value of the first voltage signal is lower than a voltage value of the second voltage signal;

[0009] An overcurrent protection circuit, wherein the output end of the threshold voltage adjustment circuit is connected to the first input end of the overcurrent protection circuit, and is used to obtain the threshold voltage signal, and generate an overcurrent protection signal based on the overcurrent detection signal of the target circuit and the threshold voltage signal.

[0010] The above technical solution has the following advantages or beneficial effects: the overcurrent protection circuit threshold can be adjusted through the temperature detection circuit, so that the overcurrent protection circuit threshold can be lowered at high temperatures, preventing the large current generated on the power side at high temperatures from damaging the circuit module of the target circuit, and also better protecting the related loads of the target circuit.

[0011] In some embodiments of the present application, the threshold voltage adjustment circuit includes:

[0012] at least one first switch element, wherein a control end of the first switch element is connected to an output end of the temperature detection circuit;

[0013] at least one first resistor, each of the first resistors being connected between a first terminal and a second terminal of one of the first switching elements;

[0014] a second resistor, the second resistor being connected in series with at least one of the first resistors, and a second end of the second resistor being grounded;

[0015] A second switch element, wherein a first end of the second switch element is connected to an input power supply, a second end of the second switch element is connected to a first end of the first resistor, and an output end of the threshold voltage adjustment circuit is arranged at a second end of the second switch element.

[0016] The above technical solution has the following advantages or beneficial effects: a one-to-one corresponding first switch element and a first resistor are set in the threshold voltage adjustment circuit, and the conduction or cutoff of the first switch element is controlled by the output signal of the temperature detection circuit. The conduction or cutoff of the first switch element is used to determine whether the corresponding second resistor is connected to the threshold voltage adjustment circuit, thereby adjusting the voltage value of the threshold voltage signal output by the threshold voltage adjustment circuit.

[0017] In some embodiments of the present application, the threshold voltage adjustment circuit further includes:

[0018] A first operational amplifier, wherein a non-inverting input terminal of the first operational amplifier is connected to a reference voltage signal, an inverting input terminal of the first operational amplifier is connected to a first terminal of the second resistor, and an output terminal of the first operational amplifier is connected to a control terminal of the second switch element.

[0019] The above technical solution has the following advantages or beneficial effects: by setting a first operational amplifier, the reference voltage is copied between the first resistor and the second resistor, so that the threshold voltage signal can be adjusted by adjusting the first resistor and the second resistor. By copying the reference voltage between the first resistor and the second resistor, it is beneficial to accurately control the threshold voltage signal.

[0020] In some embodiments of the present application, when the ambient temperature is within the threshold temperature range, the temperature detection voltage signal controls all of the first switch elements to be turned off, and the second voltage signal is determined based on the second resistor, the reference voltage signal, and all of the first resistors;

[0021] When the ambient temperature is within a first temperature interval, the lower limit of the first temperature interval is higher than the upper limit of the threshold temperature range, and the temperature detection voltage control signal controls at least one of the first switching elements to be turned on, so that all of the first resistors corresponding to the first switching element that is cut off are connected to the output circuit of the first voltage signal, and the first voltage signal is determined based on the second resistor, the reference voltage signal, and all of the first resistors corresponding to the first switching element that is cut off.

[0022] The above technical solution has the following advantages or beneficial effects: when at least one first switching element is cut off, it means that at least one first resistor is connected to the output circuit of the first voltage signal. At this time, the threshold voltage signal needs to be obtained through the connected first resistor, the second resistor and the reference voltage. Therefore, the voltage values ​​of the first voltage signal and the second voltage signal can be adjusted by adjusting the resistance values ​​of the first resistor and the second resistor and the number of connected first resistors.

[0023] In some embodiments of the present application, the temperature detection circuit includes:

[0024] A temperature acquisition circuit is used to acquire the ambient temperature of the target circuit and obtain a temperature acquisition signal whose voltage value is proportional to the ambient temperature;

[0025] At least one first comparator, used to perform temperature detection based on the temperature acquisition signal and a preset temperature threshold, and output at least one temperature detection voltage signal;

[0026] The inverting input terminal of the first comparator is used to input a reference voltage signal corresponding to the temperature threshold, and the non-inverting input terminal of the first comparator is connected to the output terminal of the temperature acquisition circuit.

[0027] The above technical solution has the following advantages or beneficial effects:

[0028] By setting the reference voltage signal, the output signal of the first comparator can be adjusted, so that the corresponding temperature detection voltage signal can be output at a preset temperature according to different output signals of the temperature acquisition circuit, thereby realizing temperature detection of the preset temperature.

[0029] In some embodiments of the present application, when there are multiple first comparators, the temperature threshold value in each of the first comparators is different.

[0030] The above technical solution has the following advantages or beneficial effects: by setting different temperature thresholds, the voltage value of the temperature detection voltage signal output by the comparator at different ambient temperatures can be controlled, and then the first resistor can be controlled to be turned on as a current path, thereby adjusting the voltage value of the threshold voltage signal.

[0031] In some embodiments of the present application, the overcurrent protection circuit includes:

[0032] An overcurrent signal acquisition circuit is used to collect the input current or output current of the target circuit to obtain the overcurrent detection signal, and the voltage value of the overcurrent detection signal is proportional to the current;

[0033] A second comparator is used to perform overcurrent detection based on the overcurrent detection signal and the threshold voltage signal to generate an overcurrent protection signal; the inverting input terminal of the second comparator is connected to the output terminal of the threshold voltage adjustment circuit, and the non-inverting input terminal of the second comparator is connected to the output terminal of the overcurrent signal acquisition circuit.

[0034] The above technical solution has the following advantages or beneficial effects: by connecting with the output end of the threshold voltage adjustment circuit, the output signal of the second comparator can be adjusted based on the ambient temperature, thereby realizing temperature-based overcurrent protection.

[0035] According to a second aspect of the present application, a gate driving chip is provided, the gate driving chip comprising a gate driving circuit and the above-mentioned overcurrent protection circuit;

[0036] The overcurrent protection circuit is used to control the threshold voltage during overcurrent protection based on the ambient temperature of the target circuit and generate a corresponding overcurrent protection signal;

[0037] The gate drive circuit is used to output a gate drive current signal under the control of the overcurrent protection signal.

[0038] The above technical solution has the following advantages or beneficial effects: since the gate drive chip includes the above overcurrent protection circuit, it can prevent the large current generated on the power side in a high temperature environment from damaging the chip, and can also better protect the chip load.

[0039] According to a third aspect of the present application, an electronic device is provided, comprising a load circuit and the above-mentioned gate drive chip, wherein an output end of the gate drive chip is connected to an input end of the load circuit.

[0040] The above technical solution has the following advantages or beneficial effects: since the electronic device includes a gate drive chip, it can prevent the large current generated on the power side in a high temperature environment from damaging the electronic device.

[0041] The overcurrent protection circuit of the present application adjusts the overcurrent protection circuit threshold through a temperature detection circuit, thereby lowering the overcurrent protection circuit threshold at high temperatures, preventing the large current generated on the power side in a high temperature environment from damaging the circuit module of the target circuit, while also better protecting the related loads of the target circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and other purposes, features and advantages of the present invention will become more apparent by describing the embodiments of the present invention in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0043] Figure 1 is a schematic block diagram of an overcurrent protection circuit according to some embodiments of the present application;

[0044] Figure 2 is a schematic block diagram of a threshold voltage adjustment circuit according to some embodiments of the present application;

[0045] Figure 3 is a schematic block diagram of a temperature detection circuit according to some embodiments of the present application;

[0046] Figure 4 is a schematic block diagram of an overcurrent protection circuit according to some embodiments of the present application;

[0047] Figure 5 is a schematic block diagram of a gate driving chip according to some embodiments of the present application;

[0048] Figure 6 is a schematic block diagram of a gate driving chip according to some other embodiments of the present application;

[0049] Figure 7is a schematic block diagram of an electronic device according to some embodiments of the present application. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0051] In view of the problem that in existing electronic products, once the current setting value in the overcurrent protection circuit is determined, the large current generated on the power side under high temperature conditions can easily damage the load module and the driver chip, the present application proposes an overcurrent protection circuit, a gate driver chip and an electronic device, which are described in detail below.

[0052] First, refer to Figure 1 The overcurrent protection circuit 100 according to some embodiments of the present application is described.

[0053] like Figure 1 As shown, the overcurrent protection circuit 100 includes:

[0054] The temperature detection circuit 110 is used to detect the ambient temperature of the target circuit and output a temperature detection voltage signal;

[0055] The threshold voltage adjustment circuit 120, the output end of the temperature detection circuit 110 is connected to the control end of the threshold voltage adjustment circuit 120, and is used to output a threshold voltage signal based on the temperature detection voltage signal, wherein when the ambient temperature exceeds the threshold temperature range, the threshold voltage signal is a first voltage signal, and when the ambient temperature is within the threshold temperature range, the threshold voltage signal is a second voltage signal, and the voltage value of the first voltage signal is lower than the voltage value of the second voltage signal;

[0056] The overcurrent protection circuit 130, the output end of the threshold voltage adjustment circuit 120 is connected to the first input end of the overcurrent protection circuit 130, for obtaining a threshold voltage signal, and generating an overcurrent protection signal based on the overcurrent detection signal of the target circuit and the threshold voltage signal.

[0057] The overcurrent protection circuit of the present application can be applied to any circuit module that requires overcurrent protection. The overcurrent protection circuit can be set independently or integrated with the circuit module. The present application does not make any specific limitations on this.

[0058] It should be noted that Figure 1The components and structure of the overcurrent protection circuit 100 shown are merely exemplary and not restrictive. The overcurrent protection circuit may also have other components and structures as required.

[0059] In some embodiments of the present application, the threshold voltage adjustment circuit includes: at least one first switching element, the control end of the first switching element is connected to the output end of the temperature detection circuit; at least one first resistor, each first resistor is connected between the first end and the second end of a first switching element; a second resistor, the second resistor is connected in series with at least one first resistor, and the second end of the second resistor is grounded; a second switching element, the first end of the second switching element is connected to the input power supply, the second end of the second switching element is connected to the first end of the first resistor, and the output end of the threshold voltage adjustment circuit is set at the second end of the second switching element.

[0060] Next, refer to Figure 2 The threshold voltage adjustment circuit according to some embodiments of the present application is described.

[0061] like Figure 2 As shown, a second switch element Q2, a second resistor R2 and at least one first resistor R11 are connected in series between the power supply VCC and the ground, and the output terminal VOUT of the threshold voltage adjustment circuit is set between the second switch element Q2 and the first resistor R11. There can be multiple first resistors R11, and when there are multiple first resistors, they are first resistors R11, R12...R1n, respectively, where n is the number of first resistors, and the first resistors R11, R12...R1n are respectively connected in parallel with the first switch elements Q11, Q12...Q1n. By way of example, when there are multiple first resistors, the resistance value of each first resistor can be the same or different. By way of example, there can also be multiple second resistors R2, and the number of second resistors R2 can be selected according to actual conditions. This application is not limited thereto. In the embodiment of this application, one second resistor R2 is used as an example for explanation. The control signals of the first switch elements Q11, Q12...Q1n are respectively the temperature detection voltage signals EN1, EN2...ENn, which are respectively connected to the control ends of the first switch elements Q11, Q12...Q1n, so as to control the on and off of the first switch elements Q11, Q12...Q1n, so as to control the number of the first resistors R11, R12...R1n connected to the threshold voltage adjustment circuit, so as to adjust the resistance value in the threshold voltage adjustment circuit, and adjust the output voltage VOUT of the threshold voltage adjustment circuit by the resistance value, and make the threshold voltage signal in the overcurrent protection circuit different by different output voltages VOUT, so as to perform overcurrent protection by adjusting the threshold value with the temperature.

[0062] According to the threshold voltage adjustment circuit provided in the present application, a first resistor and a first switching device connected in parallel with the first resistor are set, and the conduction or cutoff of the first switching element is controlled by the output signal of the temperature detection circuit. The conduction or cutoff of the first switching element is used to determine whether the corresponding second resistor is connected to the threshold voltage adjustment circuit, thereby adjusting the voltage value of the threshold voltage signal output by the threshold voltage adjustment circuit.

[0063] Exemplarily, the first switch element may be a transistor such as a metal-oxide semiconductor field effect transistor (MOSFET). Specifically, Figure 2 The first switch element shown in the figure is a PMOS tube. The drain of the first switch element Q11 is connected to the first end of the first resistor R11, the second end of the first resistor R11 is connected to the first end of the first resistor R12, the source of the first switch element Q11 is connected to the drain of the first switch element Q12 and the second end of the first resistor R11, the gate of the first switch element Q11 is connected to the control signal EN1, and so on. The connections of other first switch elements are not repeated.

[0064] Exemplarily, the threshold voltage adjustment circuit also includes: a first operational amplifier, a non-inverting input terminal of the first operational amplifier is connected to a reference voltage signal, an inverting input terminal of the first operational amplifier is connected to a first end of a second resistor, and an output terminal of the first operational amplifier is connected to a control terminal of a second switching element.

[0065] By setting a first operational amplifier, the reference voltage is copied between the first resistor and the second resistor, so that the threshold voltage signal can be adjusted by adjusting the first resistor and the second resistor. By copying the reference voltage between the first resistor and the second resistor, it is beneficial to accurately control the threshold voltage signal.

[0066] like Figure 2 As shown, the non-inverting input terminal of the first operational amplifier A1 is connected to the reference voltage VREF, the inverting input terminal of the first operational amplifier A1 is connected to the first end of the second resistor R2, and the output terminal of the first operational amplifier A1 is connected to the control terminal of the second switch element Q2. Exemplarily, the second switch element is a PMOS tube, and the output terminal of the first operational amplifier A1 is connected to the control terminal of the second switch element Q2, which is the gate of the PMOS tube, so that the voltage V1 at the first end of the second resistor R2 is equal to the reference voltage VREF, that is, the reference voltage VREF is copied to the first end of the second resistor R2. The drain of the second switch element Q2 is connected to the power supply VCC, the source of the second switch element Q2 is connected to the first end of the first resistor R11, and the connection node between the source of the second switch element Q2 and the first end of the first resistor R11 is the output terminal of the first drive circuit.

[0067] Exemplarily, when the ambient temperature is within the threshold temperature range, the temperature detection voltage signal controls all the first switching elements to be turned off, and the second voltage signal is determined based on the second resistor, the reference voltage signal and all the first resistors; when the ambient temperature is within the first temperature interval, the lower limit of the first temperature interval is higher than the upper limit of the threshold temperature range, and the temperature detection voltage control signal controls at least one first switching element to be turned on, so that all the first resistors corresponding to the first switching elements that are turned off are connected to the output circuit of the first voltage signal, and the first voltage signal is determined based on the second resistor, the reference voltage signal and all the first resistors corresponding to the first switching elements that are turned off.

[0068] When at least one first switching element is cut off, it means that at least one first resistor is connected to the output circuit of the first voltage signal. At this time, the threshold voltage signal needs to be obtained through the connected first resistor, the second resistor and the reference voltage. Therefore, the voltage values ​​of the first voltage signal and the second voltage signal can be adjusted by adjusting the resistance values ​​of the first resistor, the second resistor and the number of connected first resistors.

[0069] When the temperature detection voltage signal controls the first switch element to be turned on, the voltage value of the threshold voltage signal is equal to the voltage value of the reference voltage signal.

[0070] In order to simplify the description process, the embodiment of the present application will take two first resistors and two first switch elements as an example to specifically describe the voltage value of the threshold voltage signal.

[0071] The first resistors R11 and R12 are connected in series with the second resistor R2, the first end of the second resistor R2 is connected to the second end of the first resistor R12, and the second end of the second resistor R2 is grounded. The first switch elements corresponding to the first resistors R11 and R12 are Q11 and Q12 respectively.

[0072] Exemplarily, when Q12 of the first switch elements Q11 and Q12 is turned off, the first resistor R12 corresponding to the first switch element Q12 is connected to the threshold voltage adjustment circuit. At this time, the resistance of the threshold voltage adjustment circuit is related to the second resistor R2 and the first resistor R12 connected to the threshold voltage adjustment circuit, and the output voltage VOUT=V1+V1*R12 / R2=VREF+VREF*R12 / R2. When the first switch elements Q11 and Q12 are both turned off, the first resistors R11 and R12 are both connected to the threshold voltage adjustment circuit, and at this time, the output voltage VOUT=V1+V1*(R11+R12) / R2=VREF+VREF*(R11+R12) / R2. When the first switch elements Q11 and Q12 are both turned on, no first resistor is connected to the threshold voltage adjustment circuit, and at this time, the output voltage VOUT=V1=VREF. The output voltage is adjusted by controlling the on and off of the first switch element and thereby controlling the number of first resistors connected to the threshold voltage adjustment circuit.

[0073] Next, refer to Figure 3 To describe the temperature detection circuit according to some embodiments of the present application.

[0074] like Figure 3 As shown, the temperature detection circuit includes: a temperature acquisition circuit and at least one first comparator.

[0075] The temperature acquisition circuit is used to acquire the ambient temperature of the target circuit and obtain a temperature acquisition signal whose voltage value is proportional to the ambient temperature.

[0076] At least one first comparator is used to perform temperature detection based on the temperature acquisition signal and a preset temperature threshold, and output at least one temperature detection voltage signal; the inverting input terminal of the first comparator is used to input a reference voltage signal corresponding to the temperature threshold, and the non-inverting input terminal of the first comparator is connected to the output terminal of the temperature acquisition circuit.

[0077] Specifically, Figure 3 There are multiple first comparators C11, which are first comparators C11, C12, ..., C1n, respectively, wherein n is the number of the first comparators and also the number of the first resistors, that is, the first comparators are arranged in a one-to-one correspondence with the first resistors.

[0078] The same-direction input terminals of the first comparators C11, C12...C1n are all connected to the output terminals of the temperature acquisition circuit, and the reference voltage signals VERF1, VERF2...VERF1n corresponding to the temperature threshold are input to the reverse input terminals of the first comparators C11, C12...C1n. The voltage values ​​of the temperature acquisition signals of the temperature acquisition circuit are compared with the reference voltage signals VERF1, VERF2...VERF1n, respectively, to obtain temperature detection voltage signals EN1, EN2...ENn. The temperature detection voltage signal is a logic signal, which is at a low level at a low temperature and flips to a high level when the temperature reaches the set high temperature.

[0079] It should be noted that the reference voltage signals VERF1, VERF2, ... VERF1 can be generated by a bandgap reference circuit, and their voltage values ​​are all different, which can be set according to actual needs. The present application does not specifically limit the specific voltage value of the reference voltage signal. By setting different reference voltage signals, the number of high-level temperature detection voltage signals output by the comparator at different ambient temperatures can be controlled, thereby controlling the number of first resistors that are turned on as the current path, thereby adjusting the voltage value of the threshold voltage signal.

[0080] Next, refer to Figure 4 To describe the overcurrent protection circuit according to some embodiments of the present application.

[0081] like Figure 4 As shown, the overcurrent protection circuit includes an overcurrent signal acquisition circuit and a second comparator.

[0082] The overcurrent signal acquisition circuit is used to collect the input current or output current of the target circuit to obtain an overcurrent detection signal. The voltage value of the overcurrent detection signal is proportional to the current size.

[0083] The inverting input terminal of the second comparator C2 is connected to the output terminal of the threshold voltage adjustment circuit, the output threshold voltage signal of the threshold voltage adjustment circuit is used as the reference signal of the second comparator C2, and the non-inverting input terminal of the second comparator C2 is connected to the output terminal of the overcurrent signal acquisition circuit. The overcurrent detection signal is compared with the threshold voltage signal output by the threshold voltage adjustment circuit to generate an overcurrent protection signal OCP.

[0084] See also Figure 2 and Figure 4, take the EN1 signal as an example. At normal temperature, the EN1 signal is at a low level. At high temperature, the EN1 signal flips, the first resistor R11 is shorted in the circuit and does not work, the threshold voltage signal, that is, the reference voltage, is reduced, and the second comparator will flip when the overcurrent signal is at a lower voltage, that is, the threshold of the second comparator can become lower as the temperature rises. That is, at high temperatures, a smaller current is generated on the power side to flip the overcurrent protection function, thereby reducing the damage to the power chip caused by large current under high temperature conditions, that is, it can protect the power device under high temperature conditions and increase the working life of the module under high temperature conditions.

[0085] On the other hand, the present application Figure 5 As shown, a gate driving chip 200 is also provided, comprising an overcurrent protection circuit 210 and a gate driving circuit 220 as in any of the above embodiments.

[0086] An overcurrent protection circuit 210 is used to control a threshold voltage during overcurrent protection based on an ambient temperature of a target circuit and generate a corresponding overcurrent protection signal;

[0087] The gate driving circuit 220 is used to output a gate driving current signal under the control of the overcurrent protection signal.

[0088] Next, refer to Figure 6 To describe the gate driving chip according to some embodiments of the present application.

[0089] like Figure 6 As shown, the gate driving chip includes an overcurrent protection circuit 210 , a bandgap reference circuit 221 , a low voltage drop linear regulator 222 , an input circuit 223 , a logic control circuit 224 and a gate driving circuit 225 .

[0090] In this embodiment, the logic control circuit 224 can be a controller, and the controller can adopt various controllers commonly used by those skilled in the art, such as a single-chip microcomputer controller, a microcontroller unit, and a programmable logic controller. The bandgap reference circuit 221 and the low-voltage dropout linear regulator 222 generate a low-voltage power supply for the internal operation of the chip, and the low-voltage power supply supplies power to the logic control circuit 224 and the gate drive circuit 225. The input circuit is used to input the control signal of the logic control circuit. The bandgap reference circuit 221 is also used to generate a reference voltage with a zero temperature coefficient, and then the reference voltage for temperature detection in the overcurrent protection circuit is generated by this zero temperature coefficient reference voltage. The overcurrent protection circuit adjusts the overcurrent protection circuit threshold through the temperature detection result, thereby preventing the large current generated on the power side from damaging the gate drive chip at high temperature, and at the same time better protecting the load of the gate drive chip.

[0091] On the other hand, the present application Figure 7As shown, an electronic device 300 is also provided, including a load circuit 310 and a gate driving chip 320 as in any of the above embodiments, wherein the output end of the gate driving chip 320 is connected to the input end of the load circuit 310 .

[0092] Exemplarily, the load circuit 310 may include a device to be driven, and the device to be driven may be any controllable switch device, such as a power device such as an insulated gate bipolar transistor (IGBT) or a transistor such as a metal-oxide semiconductor field effect tube (MOSFET), that is, the gate drive chip of the present application may be used to control the conduction and cutoff of switch elements such as IGBT or MOSFET. For example, when the load circuit is an IGBT, the output end of the gate drive chip 320 is connected to the gate of the IGBT, and the electronic device may be any electronic product or device such as a household appliance (such as a variable frequency air conditioner), a television, a mobile phone, a tablet computer, a laptop computer, a netbook, a game console, a television, a VCD, a DVD, a navigator, a camera, a video camera, a voice recorder, an MP3, an MP4, a PSP, etc., or an intermediate product having the above-mentioned gate drive chip, such as: a mobile phone motherboard having the integrated circuit, etc., or the electronic device 300 may also be a transportation device such as a vehicle.

[0093] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as required by the appended claims.

[0094] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0095] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0096] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0097] Similarly, it should be understood that in order to streamline the present invention and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0098] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0099] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0100] The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functions of some modules in the article analysis device according to an embodiment of the present invention. The present invention may also be implemented as a device program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0101] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed 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 a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices 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.

[0102] The above is only a specific embodiment of the present invention or an explanation of a specific embodiment. The protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An overcurrent protection circuit, characterized in that: The overcurrent protection circuit comprises: A temperature detection circuit is used to detect the ambient temperature of the target circuit and output a temperature detection voltage signal; a threshold voltage adjustment circuit, wherein the output end of the temperature detection circuit is connected to the control end of the threshold voltage adjustment circuit, and is used to output a threshold voltage signal based on the temperature detection voltage signal, wherein when the ambient temperature exceeds a threshold temperature range, the threshold voltage signal is a first voltage signal, and when the ambient temperature is within the threshold temperature range, the threshold voltage signal is a second voltage signal, and a voltage value of the first voltage signal is lower than a voltage value of the second voltage signal; An overcurrent protection circuit, wherein the output end of the threshold voltage adjustment circuit is connected to the first input end of the overcurrent protection circuit, and is used to obtain the threshold voltage signal, and generate an overcurrent protection signal based on the overcurrent detection signal of the target circuit and the threshold voltage signal.

2. The overcurrent protection circuit as claimed in claim 1, characterized in that: The threshold voltage adjustment circuit comprises: at least one first switch element, wherein a control end of the first switch element is connected to an output end of the temperature detection circuit; at least one first resistor, each of the first resistors being connected between a first terminal and a second terminal of one of the first switching elements; a second resistor, the second resistor being connected in series with at least one of the first resistors, and a second end of the second resistor being grounded; A second switch element, wherein a first end of the second switch element is connected to an input power supply, a second end of the second switch element is connected to a first end of the first resistor, and an output end of the threshold voltage adjustment circuit is arranged at a second end of the second switch element.

3. The overcurrent protection circuit as claimed in claim 2, characterized in that: The threshold voltage adjustment circuit further includes: A first operational amplifier, wherein a non-inverting input terminal of the first operational amplifier is connected to a reference voltage signal, an inverting input terminal of the first operational amplifier is connected to a first terminal of the second resistor, and an output terminal of the first operational amplifier is connected to a control terminal of the second switch element.

4. The overcurrent protection circuit as claimed in claim 3, characterized in that: When the ambient temperature is within the threshold temperature range, the temperature detection voltage signal controls all the first switch elements to be turned off, and the second voltage signal is determined based on the second resistor, the reference voltage signal and all the first resistors; When the ambient temperature is within a first temperature interval, the lower limit of the first temperature interval is higher than the upper limit of the threshold temperature range, and the temperature detection voltage control signal controls at least one of the first switching elements to be turned on, so that all of the first resistors corresponding to the first switching element that is cut off are connected to the output circuit of the first voltage signal, and the first voltage signal is determined based on the second resistor, the reference voltage signal, and all of the first resistors corresponding to the first switching element that is cut off.

5. The overcurrent protection circuit as claimed in claim 1, characterized in that: The temperature detection circuit comprises: A temperature acquisition circuit is used to acquire the ambient temperature of the target circuit and obtain a temperature acquisition signal whose voltage value is proportional to the ambient temperature; At least one first comparator, used to perform temperature detection based on the temperature acquisition signal and a preset temperature threshold, and output at least one temperature detection voltage signal; The inverting input terminal of the first comparator is used to input a reference voltage signal corresponding to the temperature threshold, and the non-inverting input terminal of the first comparator is connected to the output terminal of the temperature acquisition circuit.

6. The overcurrent protection circuit according to claim 5, characterized in that: When there are multiple first comparators, the temperature threshold value in each of the first comparators is different.

7. The overcurrent protection circuit according to claim 1, characterized in that: The overcurrent protection circuit comprises: An overcurrent signal acquisition circuit is used to collect the input current or output current of the target circuit to obtain the overcurrent detection signal, and the voltage value of the overcurrent detection signal is proportional to the current; A second comparator is used to perform overcurrent detection based on the overcurrent detection signal and the threshold voltage signal to generate an overcurrent protection signal; the inverting input terminal of the second comparator is connected to the output terminal of the threshold voltage adjustment circuit, and the non-inverting input terminal of the second comparator is connected to the output terminal of the overcurrent signal acquisition circuit.

8. A gate driver chip, characterized in that: The gate drive chip comprises a gate drive circuit and an overcurrent protection circuit as described in any one of claims 1 to 7; The overcurrent protection circuit is used to control the threshold voltage during overcurrent protection based on the ambient temperature of the target circuit and generate a corresponding overcurrent protection signal; The gate drive circuit is used to output a gate drive current signal under the control of the overcurrent protection signal.

9. An electronic device, characterized in that: The electronic device comprises a load circuit and the gate driving chip according to claim 8, wherein an output end of the gate driving chip is connected to an input end of the load circuit.

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