Gate driving circuit, gate driving chip and electronic equipment

Abstract

A gate drive circuit, a gate drive chip and an electronic device, the gate drive circuit comprising: a temperature detection port electrically connected with a temperature acquisition end of a power device and used for acquiring a sampling signal from the temperature acquisition end of the power device, the sampling signal characterizing the temperature of the power device during operation; and the current adjusting circuit is electrically connected with the temperature detection port and is used for adjusting the gate driving current of the power device based on the sampling signal so as to adjust the switching speed of the power device. According to the gate drive circuit, after the temperature information of the power device during working is obtained by using the existing temperature detection port, the current adjusting unit can adjust the gate drive current of the power device based on the temperature information, so that the existing resources can be better utilized, the resource utilization rate is improved, and the compatibility problem caused by changing the original pin is avoided; and the switching speed of the power device can be adjusted by adjusting the gate driving current of the power device, so that the characteristic deviation between the power devices is reduced or even eliminated.

Description

Technical Field

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

[0002] Due to production process, packaging and other factors, the characteristics of one or more batches of insulated gate bipolar transistors (IGBTs) may deviate. When the characteristics of these IGBTs deviate, it will have adverse effects on the modules that use them. For example, the same gate drive circuit is used to drive the IGBTs of the same batch, but due to the deviation of the IGBT characteristics, different results are obtained by using the same drive method, which will not meet the user's expectations.

[0003] Therefore, a solution that can reduce or eliminate such characteristic deviation is needed. Summary of the invention

[0004] According to one aspect of the present application, a gate driving circuit is provided, the gate driving circuit comprising:

[0005] A temperature detection port, electrically connected to a temperature acquisition terminal of a power device, and used to obtain a sampling signal from the temperature acquisition terminal of the power device, wherein the sampling signal represents the temperature of the power device when it is working;

[0006] A current regulating circuit is electrically connected to the temperature detection port and is used to regulate the gate drive current of the power device based on the sampling signal to regulate the switching speed of the power device.

[0007] The above technical solution has the following technical effects: a current regulation circuit is added on the basis of the existing temperature detection port in the driver chip, and the current regulation circuit obtains the temperature information of the power device when it is working based on the temperature detection port, and adjusts the gate drive current of the power device based on the temperature information. Therefore, it can not only better utilize existing resources and improve resource utilization, avoid compatibility problems caused by changing the original pins, but also adjust the switching speed of the power device by adjusting the gate drive current of the power device, thereby reducing or even eliminating the characteristic deviation between the power devices.

[0008] In an embodiment of the present application, the current regulating circuit includes:

[0009] A signal conversion unit, used for converting the sampled signal from an analog signal into at least two digital signals;

[0010] At least two current regulating units, each of which is connected to one of the digital signals and is used to be turned on or off based on the digital signal, thereby increasing or decreasing the gate drive current of the power device.

[0011] The above technical solution has the following technical effects: a sampling signal representing the temperature of a power device during operation is converted from an analog signal into a multi-channel digital signal through a signal conversion unit, one channel of the digital signal is used to control the on or off of a current regulation unit, and different numbers of current regulation units have different current regulation effects on the gate drive current, thereby being able to conveniently increase or decrease the gate drive current.

[0012] In an embodiment of the present application, the signal conversion unit includes:

[0013] At least two comparators, the positive input terminal of each comparator is connected to the temperature detection port, the negative input terminal of each comparator is connected to the reference signal input terminal, and the output terminal of each comparator outputs one digital signal.

[0014] The above technical solution has the following technical effects: each comparator can compare the sampled signal with its reference signal and output a digital signal, so multiple comparators can perform this operation separately to output multiple digital signals, and one digital signal is used to control a current regulation unit, thereby realizing the regulation of the gate drive current.

[0015] In an embodiment of the present application, the reference signals input to each of the reference signal input terminals have different sizes.

[0016] The above technical solution has the following technical effects: the reference signal input to the negative input terminal of each comparator has different sizes, so that the sampling signal is compared with reference signals of different sizes, which can realize multi-gradient regulation of the current.

[0017] In an embodiment of the present application, the signal conversion unit further includes:

[0018] At least two inverters, an input end of each inverter is connected to one digital signal, and an output end of each inverter is connected to one current regulating unit.

[0019] The above technical solution has the following technical effects: using an inverter can simplify circuit design, reduce the number of logic devices, and reduce circuit complexity. In addition, using an inverter can make the circuit have a faster response speed, lower power consumption and higher reliability, which helps to improve the overall performance of the circuit.

[0020] In an embodiment of the present application, each of the current regulating units includes:

[0021] A multiplexer, the multiplexer comprising a first input terminal, a second input terminal, a third input terminal and an output terminal, the first input terminal is grounded, the second input terminal is connected to the input terminal of the first output stage circuit, the third input terminal is connected to one channel of the digital signal, and the output terminal of the multiplexer is connected to the input terminal of the second output stage circuit;

[0022] The second output stage circuit, the output end of the second output stage circuit and the output end of the first output stage circuit are all connected to the power device, and the input end of the first output stage circuit is connected to the input signal of the gate drive circuit.

[0023] The above technical solution has the following technical effects: through the multiplexer, which input is selected as the output according to the different digital signals connected to the multiplexer, thereby controlling the opening or closing of different output stage circuits. The opening or closing of different numbers of output stage circuits can affect the size of the gate drive current, thereby playing a role in regulating the gate drive current.

[0024] In an embodiment of the present application, each of the current regulating units includes:

[0025] a first resistor;

[0026] A switch, wherein the switch is connected in parallel to two ends of the first resistor, and the switch is connected to a path of the digital signal as a control signal of the switch;

[0027] The first resistors of different current regulating units are connected in series to form a resistor string, a first end of the resistor string is connected to an output end of an output stage circuit of the gate driving circuit, and a second end of the resistor string is connected to the power device.

[0028] The above technical solution has the following technical effects: by connecting the digital signal of the switch connected in parallel at both ends of the first resistor (i.e., the gate drive resistor), the switch can be controlled to be turned on or off, thereby controlling the short circuit or connection of the first resistor, and then controlling the number of first resistors connected to the circuit, thereby affecting the size of the gate drive resistor connected to the circuit, thereby playing a role in regulating the gate drive current.

[0029] In an embodiment of the present application, the current regulating circuit further includes:

[0030] A second resistor, wherein a first end of the second resistor is connected to the output end of the output stage circuit, and a second end of the second resistor is connected to the first end of the resistor string.

[0031] The above technical solution has the following technical effects: adding a gate drive resistor that is not controlled by the digital signal output by the signal conversion unit can achieve additional control of the gate drive current.

[0032] In an embodiment of the present application, the at least two current regulating units include:

[0033] At least one first current regulating unit, each of the first current regulating units comprising:

[0034] A multiplexer, the multiplexer comprising a first input terminal, a second input terminal, a third input terminal and an output terminal, the first input terminal is grounded, the second input terminal is connected to the input terminal of the first output stage circuit, the third input terminal is connected to one channel of the digital signal, and the output terminal of the multiplexer is connected to the input terminal of the second output stage circuit;

[0035] The second output stage circuit, the output end of the second output stage circuit and the output end of the first output stage circuit are both connected to the power device, and the input end of the first output stage circuit is connected to the input signal of the gate drive circuit;

[0036] At least one second current regulating unit, each of the second current regulating units comprising:

[0037] a first resistor;

[0038] A switch, wherein the switch is connected in parallel to two ends of the first resistor, and the switch is connected to a path of the digital signal as a control signal of the switch;

[0039] Among them, the first resistors of different current regulating units are connected in series to form a resistor string, the first end of the resistor string is connected to the output end of the first output stage circuit or the output end of the second output stage circuit, and the second end of the resistor string is connected to the power device.

[0040] The above technical solution has the following technical effects: through the multiplexer, which input can be selected as the output according to the different digital signals connected to the multiplexer, so as to control the opening or closing of different output stage circuits. The opening or closing of different numbers of output stage circuits can affect the size of the gate drive current, thereby playing a role in regulating the gate drive current; at the same time, the digital signal connected to the switch connected in parallel at both ends of the first resistor (that is, the gate drive resistor) can control the opening or closing of the switch, thereby controlling the short circuit or connection of the first resistor, and then controlling the number of the first resistor connected to the circuit, thereby affecting the size of the gate drive resistor connected to the circuit, thereby playing a role in regulating the gate drive current. This embodiment is a combination of two current regulation methods.

[0041] In an embodiment of the present application, the gate drive circuit further includes:

[0042] The control circuit is used to disconnect the electrical connection between the temperature detection port and the temperature collection terminal of the power device when the gate drive current of the power device does not need to be adjusted.

[0043] The above technical solution has the following technical effects: when the gate drive current of the power device does not need to be adjusted, the electrical connection between the temperature detection port and the temperature collection end of the power device is disconnected, so that the temperature detection port of the gate drive circuit resumes its own function, and its output represents the temperature of the gate drive circuit itself when it is working, which is convenient for over-temperature protection of the gate drive circuit.

[0044] According to another aspect of the present application, a gate driving chip is further provided, and the gate driving chip includes the above-mentioned gate driving circuit.

[0045] According to another aspect of the present application, an electronic device is provided, comprising the above-mentioned gate driving chip.

[0046] According to the gate drive circuit, gate drive chip and electronic device of the embodiments of the present application, after using the existing temperature detection port of the gate drive circuit to obtain the temperature information of the power device during operation (a sampling signal representing the temperature), the current regulation unit can adjust the gate drive current of the power device based on the sampling signal. This can not only better utilize existing resources and improve resource utilization, avoid compatibility issues caused by changing the original pins, but also adjust the switching speed of the power device by adjusting the gate drive current of the power device, thereby reducing or even eliminating the characteristic deviation between the power devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] 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.

[0048] Figure 1 A schematic structural block diagram of a gate driving circuit according to an embodiment of the present application is shown.

[0049] Figure 2 A schematic diagram of a temperature detection port in a gate driving circuit according to an embodiment of the present application is shown.

[0050] Figure 3 A schematic structural diagram of a current regulating circuit in a gate driving circuit according to an embodiment of the present application is shown.

[0051] Figure 4A schematic diagram of a multiplexer in a current regulating unit of a gate driving circuit according to an embodiment of the present application is shown.

[0052] Figure 5 A schematic diagram showing a plurality of output stage circuits connected in parallel in a current regulating unit of a gate driving circuit according to an embodiment of the present application is shown.

[0053] Figure 6 A schematic diagram of a gate driving resistor in a current regulating unit of a gate driving circuit according to an embodiment of the present application is shown.

[0054] Figure 7 A schematic circuit diagram of a gate driving circuit according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0055] 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.

[0056] Figure 1 FIG. 1 shows a schematic structural block diagram of a gate drive circuit 1 according to an embodiment of the present application. Figure 1 As shown, the gate drive circuit 1 includes a temperature detection port 11 and a current regulation circuit 12. The temperature detection port 11 is electrically connected to the temperature acquisition terminal of the power device, and is used to obtain a sampling signal from the temperature acquisition terminal of the power device, and the sampling signal represents the temperature of the power device when it is working. The current regulation circuit 12 is electrically connected to the temperature detection port 11, and is used to adjust the gate drive current of the power device based on the sampling signal to adjust the switching speed of the power device.

[0057] The applicant of the present application has discovered that when a gate drive circuit is used to drive a power device such as an IGBT, the characteristic deviation of the IGBT caused by factors such as production process and packaging will be reflected in the switching characteristics of the IGBT, and further in the loss of the IGBT. The loss can be reflected in the temperature of the IGBT when it is working. Therefore, the loss and switching characteristics of the IGBT can be sensed by obtaining the temperature of the IGBT when it is working, and the gate drive current can be adjusted based on the temperature to adjust the switching speed of the IGBT. In this way, the characteristic deviation of the IGBT caused by factors such as production process and packaging can be reduced or even eliminated, so that when using one or more batches, a single or multiple IGBTs, the characteristic deviation of these IGBTs can be made as small as possible, which will bring great benefits to the application.

[0058] At present, each of the gate drive circuit and the IGBT has its own temperature detection circuit. Among them, the temperature detection circuit inside the gate drive circuit is used to detect the temperature inside the gate drive circuit, and outputs the signal representing the temperature via the temperature detection port 11. The temperature detection circuit at the IGBT is used to detect the temperature of the IGBT when it is working, and outputs the signal representing the temperature via the temperature detection port of the IGBT (hereinafter referred to as the temperature acquisition terminal in order to distinguish it from the temperature detection port of the gate drive circuit 11). If the gate drive circuit directly obtains the temperature of the IGBT when it is working from the temperature acquisition terminal of the IGBT, it is necessary to add a port in the gate drive circuit again, which requires changing the pin information of the gate drive circuit, which brings compatibility problems. In order not to change the pin information of the gate drive circuit and avoid compatibility problems, in an embodiment of the present application, the temperature detection port 11 of the gate drive circuit 1 is electrically connected to the temperature acquisition terminal of the IGBT, so that the temperature detection port 11 can obtain the temperature information of the IGBT when it is working.

[0059] In addition, since the temperature detection port 11 itself can be used to output the temperature information inside the gate drive circuit 1, this temperature information will conflict with the temperature information of the IGBT when it is working obtained from the IGBT temperature acquisition terminal. Therefore, when the gate drive current needs to be adjusted, in order to enable the temperature detection port 11 to output the temperature information of the IGBT when it is working, the IGBT temperature acquisition terminal can be set to a reasonable gear so that the signal value (such as voltage value) representing the IGBT temperature is higher than the signal value representing the temperature of the gate drive circuit. This will enable normal operation without conflict because the two voltages in parallel will output a relatively high voltage.

[0060] Of course, when there is no need to adjust the gate drive current, the temperature detection port 11 can be electrically disconnected from the temperature collection terminal of the IGBT, for example, through a control circuit (not shown) included in the gate drive circuit 1, so that the temperature detection port 11 of the gate drive circuit 1 can resume its function, and its output represents the temperature of the gate drive circuit 1 itself when it is working, which is convenient for over-temperature protection of the gate drive circuit 1.

[0061] After using the existing temperature detection port 11 of the gate drive circuit to obtain the temperature information of the IGBT during operation (a sampling signal representing the temperature), the current regulation unit 12 can adjust the IGBT gate drive current based on the sampling signal. This can not only make better use of existing resources and improve resource utilization, avoid compatibility issues caused by changing the original pins, but also adjust the switching speed of the power device by adjusting the gate drive current of the power device, thereby reducing or even eliminating the characteristic deviation between the power devices.

[0062] For example, for multiple IGBTs in the same application, under the same working state, the temperature of other IGBTs is the first temperature, while the temperature of one of the IGBTs is the second temperature. In one case, the second temperature is higher than the first temperature, which may be due to the process, packaging, etc. causing the IGBT to have characteristic deviations from other IGBTs. At this time, the temperature information of the IGBT during operation (i.e., a sampling signal representing the temperature) can be obtained based on the temperature detection port 11 of the gate drive circuit 1 of the IGBT, and the gate drive current of the IGBT can be reduced based on the sampling signal, thereby reducing the switching speed of the IGBT, thereby reducing the loss of the IGBT, thereby reducing the temperature of the IGBT, and finally reducing or even eliminating the characteristic deviation between the IGBT and other IGBTs.

[0063] In another case, the second temperature is lower than the first temperature, which may be due to the process, packaging, etc. causing the IGBT to have characteristic deviations from other IGBTs. At this time, the temperature information of the IGBT during operation (i.e., a sampling signal representing the temperature) can be obtained based on the temperature detection port 11 of the gate drive circuit 1 of the IGBT, and the gate drive current of the IGBT can be increased based on the sampling signal, thereby increasing the switching speed of the IGBT, thereby increasing the loss of the IGBT, thereby increasing the temperature of the IGBT, and finally reducing or even eliminating the characteristic deviations between the IGBT and other IGBTs.

[0064] In the embodiment of the present application, the temperature detection port 11 is as follows Figure 2 As shown. Among them, VPTAT is a voltage generated inside the gate drive circuit 1 that is proportional to the internal temperature of the gate drive circuit 1. After the voltage is amplified and stabilized by the operational amplifier AMP, a voltage VOT is obtained. This VOT is the temperature characterizing voltage inside the gate drive circuit 1 output by the temperature detection port 11. This VOT is also the port name of the temperature detection port 11, which is a port of the gate drive circuit 1 itself. As mentioned above, it is hoped that no new port is added to obtain the working temperature of the IGBT. Therefore, when it is necessary to adjust the gate drive current of the IGBT, this port should be electrically connected to the temperature acquisition terminal of the IGBT. When the temperature of the IGBT is collected, the voltage VOT output by this port represents the working temperature of the IGBT.

[0065] In an embodiment of the present application, the current regulating circuit 12 may further include: a signal conversion unit and at least two current regulating units. The signal conversion unit is used to convert the sampling signal representing the temperature of the power device when it is working, which is obtained by the temperature detection port 11 from the temperature acquisition end of the power device, from an analog signal to at least two digital signals; each of the at least two current regulating units is connected to one of the at least two digital signals, and is used to turn on or off based on the digital signal, thereby adjusting the gate drive current of the power device. Figure 3 to describe.

[0066] Figure 3 FIG. 1 shows a schematic structural diagram of a current regulating circuit 12 in a gate driving circuit according to an embodiment of the present application. Figure 3 As shown, the current regulating circuit 12 includes a signal conversion unit 121 and four current regulating units 122a, 122b, 122c and 122d (the four current regulating units shown here are exemplary, and other suitable numbers of current regulating units can be set as needed in practice). Among them, the signal conversion unit 121 is used to convert the sampling signal representing the temperature of the power device when the power device is working, which is obtained by the temperature detection port 11 from the temperature acquisition end of the power device, from an analog signal into four digital signals; these four digital signals are respectively used as input signals of the current regulating units 122a, 122b, 122c and 122d, and control the current regulating units 122a, 122b, 122c and 122d to turn on or off, thereby adjusting the gate drive current of the power device. Among the four current regulating units, the number of the current regulating units turned on is different, and the current regulating effect on the gate drive current is different, so that the gate drive current can be easily increased or decreased.

[0067] Exemplarily, the above-mentioned signal conversion unit may include at least two comparators, the positive input terminal of each comparator is connected to the temperature detection port 11, so as to obtain the sampling signal characterizing the temperature of the power device when it is working, which is obtained by the temperature detection port 11 from the temperature acquisition terminal of the power device, and the negative input terminal of each comparator is connected to the reference signal input terminal, so as to obtain a reference signal, and the output terminal of each comparator outputs a digital signal. In this embodiment, each comparator can compare the sampling signal with its reference signal and output a digital signal, so multiple comparators can perform this operation respectively to output multiple digital signals, and one digital signal is used to control a current regulation unit, so as to achieve the regulation of the gate drive current. For example, in Figure 3 In the example shown, the signal conversion unit 121 can be implemented using four comparators, and the sampling signal representing the temperature of the power device during operation obtained by the temperature detection port 11 from the temperature acquisition end of the power device is output as four digital signals for controlling the four current regulation units 122a to 122d.

[0068] Furthermore, the reference signal input to the reference signal input terminal connected to the negative input terminal of each comparator may be the same in size or at least partially different in size. When the reference signal input to the negative input terminal of each comparator is different in size, the sampling signal can be compared with reference signals of different sizes, so that multi-gradient regulation of the current can be achieved. This will be described later in conjunction with specific examples.

[0069] In an embodiment of the present application, the signal conversion unit may further include at least two inverters, the input end of each inverter being connected to the digital signal described above, and the output end of each inverter being connected to a current regulating unit. The use of inverters can simplify circuit design, reduce the number of logic devices, and reduce circuit complexity. In addition, the use of inverters can make the circuit have a faster response speed, lower power consumption, and higher reliability, which helps to improve the overall performance of the circuit.

[0070] In one example, each current regulating unit may include a multiplexer and a second output stage circuit. The multiplexer may include a first input terminal, a second input terminal, a third input terminal and an output terminal, the first input terminal is grounded, the second input terminal is connected to the input terminal of the first output stage circuit, the third input terminal is connected to a digital signal, the output terminal of the multiplexer is connected to the input terminal of the second output stage circuit, the output terminal of the second output stage circuit and the output terminal of the first output stage circuit are both connected to the power device, and the input terminal of the first output stage circuit is connected to the input signal of the gate drive circuit. Figure 4 and Figure 5 to describe.

[0071] Figure 4 FIG. 1 is a schematic diagram showing a multiplexer in a current regulating unit of a gate driving circuit according to an embodiment of the present application. Figure 4 As shown, the multiplexer in each current regulating unit includes three input terminals and one output terminal, wherein the sel terminal is connected to a one-bit digital signal output by the aforementioned signal conversion unit. Exemplarily, when the sel terminal is connected to a low-level signal (0), the multiplexer selects input 1 and passes it to the output terminal. Assuming that input 1 is grounded, the output terminal of the multiplexer outputs a low level, and the second output stage circuit connected thereto is turned on, and the power device can be charged. Conversely, when the sel terminal is connected to a high-level signal (1), the multiplexer selects input 2 and passes it to the output terminal. Assuming that input 2 is connected to the input terminal of the first output stage circuit, and the input terminal of the first output stage circuit is connected to the input signal of the gate drive circuit, the input signal of the gate drive circuit can control the opening or closing of the current regulating unit.

[0072] Figure 5FIG. 1 is a schematic diagram showing a plurality of output stage circuits connected in parallel in a current regulating unit of a gate drive circuit according to an embodiment of the present application. Figure 5 In the figure, n+1 output stage circuits are shown, wherein the 0th stage is the first output stage circuit described above, and the 1st to nth stages are the second output stage circuits described above. The input end of the first output stage circuit is connected to the input signal of the gate drive circuit, and the input end of the second output stage circuit is connected to the output end of the multiplexer described above. The first output stage circuit and the plurality of second output stage circuits can be regarded as replacing the original output stage circuit (with large-size transistors) of the gate drive circuit with a parallel connection of multiple output stage circuits. Alternatively, the first output stage circuit can also be understood as the original output stage circuit, and the plurality of second output stage circuits are circuits included in the newly added current conversion circuit.

[0073] In general, through the multiplexer, which input is selected as the output according to the different digital signals connected to the multiplexer, thereby controlling the opening or closing of different output stage circuits. The opening or closing of different numbers of output stage circuits can affect the size of the gate drive current, thereby playing a role in regulating the gate drive current.

[0074] In another example, each current regulating unit does not include the multiplexer and the second output stage circuit mentioned above, but includes a first resistor and a switch. The switch is connected in parallel to both ends of the first resistor, and the switch is connected to the digital signal mentioned above as the control signal of the switch. The first resistors of different current regulating units are connected in series to form a resistor string, the first end of the resistor string is connected to the output end of the output stage circuit of the gate drive circuit, and the second end of the resistor string is connected to the power device. Figure 6 to describe.

[0075] Figure 6 FIG. 1 is a schematic diagram showing a gate drive resistor in a current regulating unit of a gate drive circuit according to an embodiment of the present application. Figure 6As shown, n current regulating units are shown, each current regulating unit includes a resistor and a switch connected in parallel at both ends of the resistor, these resistors are R1 to Rn, and these switches are SW1 to SWn. Each switch is connected to a one-bit digital signal output by the aforementioned signal conversion unit, which can control the switch to be turned on or off. When switches SW1 to SWn are all disconnected, resistors R1 to Rn are not short-circuited and are all connected to the circuit. At this time, the gate drive resistance is the largest and the gate drive current is the smallest; conversely, when switches SW1 to SWn are all closed, resistors R1 to Rn are short-circuited and are not connected to the circuit. At this time, the gate drive resistance is the smallest and the gate drive current is the largest. When switches SW1 to SWn are partially disconnected and partially closed, resistors R1 to Rn are partially short-circuited and partially not short-circuited. At this time, the gate drive resistance is between the maximum value and the minimum value, and the gate drive current is between the maximum value and the minimum value. Therefore, the one-bit digital signal output by the aforementioned signal conversion unit connected to each switch can control the disconnection and closing of the switch, thereby controlling the size of the gate drive resistance, and then controlling the size of the gate drive current.

[0076] In general, in this example, the digital signal connected to the switch connected in parallel at both ends of the first resistor (also known as the gate drive resistor) can control the opening or closing of the switch, thereby controlling the short circuit or connection of the first resistor, and then controlling the number of first resistors connected to the circuit, thereby affecting the size of the gate drive resistor connected to the circuit, thereby playing a role in regulating the gate drive current.

[0077] Furthermore, the current regulating unit may further include a second resistor, such as Figure 6 The resistor R0 shown has no parallel switches at both ends and is connected between the output stage circuit and the resistor string, that is, it includes a gate drive resistor that is not controlled by the digital signal output by the signal conversion unit, which can achieve basic control or additional control of the gate drive current.

[0078] The above describes an example of a signal conversion unit included in the current regulating circuit 12, as well as an example of a circuit regulating unit, which can be combined in various ways to form different embodiments of the current regulating circuit. For example, in a first embodiment, the signal conversion unit can be implemented as a plurality of comparators, and the circuit regulating unit can be implemented as a multiplexer and a second output stage circuit; in a second embodiment, the signal conversion unit can be implemented as a plurality of comparators, and the circuit regulating unit can be implemented as a switch and a first resistor (which can also include a second resistor); in a third embodiment, the signal conversion unit can be implemented as a plurality of comparators, and the circuit regulating unit can include a first circuit regulating unit and a second circuit regulating unit, wherein the first circuit regulating unit is implemented as a multiplexer and a second output stage circuit, and the second circuit regulating unit is implemented as a switch and a first resistor (which can also include a second resistor). Now in combination Figure 7Describing the first embodiment above, other embodiments will not be elaborated in detail and can be understood according to the content described above.

[0079] Figure 7 FIG. shows a schematic circuit diagram of a gate drive circuit according to an embodiment of the present application. As Figure 7 shown, the temperature detection port VOT and the current regulation circuit described above are shown, wherein the current regulation circuit includes a signal conversion unit and a plurality of current regulation units. Among them, the signal conversion unit includes three comparators CMP1, CMP2 and CMP3, and three inverters INV1, INV2 and INV3; the current regulation unit includes multiplexers MUX1 to MUX3, and three-stage output stage circuits. The reference signals input to the negative input terminals of the three comparators included in the signal conversion unit are VREF1, VREF2 and VREF3 respectively for CMP1, CMP2 and CMP3. The working process is described in detail below:

[0080] In the default state, the reference voltage magnitudes at one end of CMP1, CMP2, and CMP3 are VREF3 > VREF2 > VREF1 > the VOT of the gate drive circuit itself. Since the VOT of the gate drive circuit itself is less than the reference values of the three comparators, the outputs of the three comparators are 0, which are then connected to the three inverters, and these three inverters are then connected to the three MUX selection circuits. It is designed that when the MUX circuit receives a 0 signal, it selects the input 1 channel, and when it receives a 1 signal, it selects the input 2 channel. Therefore, in the default state, the 0th stage, 1st stage, 2nd stage, and 3rd stage output circuits are turned on, and the total output current is the maximum. The 0th stage output circuit is turned on because in the default state, the input signal IN of the gate drive circuit is the signal that drives the 0th stage output circuit to turn on.

[0081] When a voltage is collected at the IGBT temperature acquisition terminal, assuming VREF2 < VOT of the temperature acquisition terminal < VREF3, then at this time, the outputs of CMP1 and CMP2 are 1, and the output of CMP3 is 0. After passing through the inverters and the MUX circuit, at this time, MUX1 and MUX2 select the input 1 for output, and MUX3 selects the input 2 for output, that is, the 1st stage output stage circuit and the 2nd stage output stage circuit are turned off at this time, and the 0th stage and 3rd stage circuits are retained for output. At this time, the total output current is reduced compared to the default state, the IGBT switching characteristics become slower, and the loss is reduced. When the voltage at the temperature acquisition terminal is very high, then all three comparators output 1. At this time, MUX1, MUX2, and MUX3 all select the input 1 for output, that is, only the 0th stage circuit outputs current outward, and the total output current is the smallest at this time.

[0082] Figure 7 The embodiment scheme described above describes a scheme of parallel connection of multi-stage output circuits. Similarly, the multi-stage output circuits can be replaced with Figure 6The following structure takes three switches as an example to illustrate a specific implementation. Connect the Figure 6 switch SW shown in the figure to the outputs of inverters INV1, INV2, and INV3. In the default state, VREF3 > VREF2 > VREF1 > the VOT of the gate drive circuit itself. The three comparators output 0, which is then inverted to output 1 by the inverters. The three switches close, and the three resistors are equivalent to being short-circuited, and the total output current is the largest. When a voltage is collected at the IGBT temperature acquisition terminal, assuming VREF2 < the VOT of the temperature acquisition terminal < VREF3, then at this time, CMP1 and CMP2 output 1, CMP3 outputs 0, inverter INV1 outputs 0, INV2 outputs 0, and INV3 outputs 1. Only SW1 and SW2 close, and the output current decreases compared to the default state.

[0083] In addition, as described above, the scheme for adjusting the output stage circuit can be combined with the scheme for adjusting the gate drive resistance.

[0084] The gate drive circuit according to the embodiment of the present application is described in detail above. Based on the above description, after the gate drive circuit according to the embodiment of the present application obtains the temperature information (sampling signal representing the temperature) of the power device during operation by using the existing temperature detection port, the current adjustment unit can adjust the gate drive current of the power device based on this sampling signal. It can not only make better use of existing resources, improve the resource utilization rate, avoid compatibility problems caused by changing the original pins, but also adjust the switching speed of the power device by adjusting the gate drive current of the power device, thereby reducing or even eliminating the characteristic deviation between power devices.

[0085] According to another aspect of the present application, a gate drive chip is also provided. The gate drive chip includes the gate drive circuit according to the embodiment of the present application described above.

[0086] According to still another aspect of the present application, an electronic device is also provided. The electronic device includes the above-mentioned gate drive chip.

[0087] Although example embodiments have been described herein with reference to the drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.

[0088] Those of ordinary skill 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 this application.

[0089] 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.

[0090] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application 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.

[0091] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly 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 features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0092] 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.

[0093] In addition, those skilled in the art will appreciate that, although some embodiments 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 application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0094] The various component embodiments of the present application can 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) can be used in practice to implement some or all of the functions of some modules in the article analysis device according to the embodiment of the present application. The present application can also be implemented as a device program (e.g., computer program and computer program product) for executing part or all of the methods described herein. Such a program implementing the present application can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0095] 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 to 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 by means of hardware including several different elements and by means of a suitably programmed computer. In a unit claim that lists several 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.

[0096] 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 gate drive circuit, characterized in that: The gate drive circuit comprises: A temperature detection port, electrically connected to a temperature acquisition terminal of a power device, and used to obtain a sampling signal from the temperature acquisition terminal of the power device, wherein the sampling signal represents the temperature of the power device when it is working; A current regulating circuit is electrically connected to the temperature detection port and is used to regulate the gate drive current of the power device based on the sampling signal to regulate the switching speed of the power device.

2. The gate driving circuit according to claim 1, characterized in that: The current regulating circuit comprises: A signal conversion unit, used for converting the sampled signal from an analog signal into at least two digital signals; At least two current regulating units, each of which is connected to one of the digital signals and is used to be turned on or off based on the digital signal, thereby increasing or decreasing the gate drive current of the power device.

3. The gate driving circuit according to claim 2, characterized in that: The signal conversion unit comprises: At least two comparators, the positive input terminal of each comparator is connected to the temperature detection port, the negative input terminal of each comparator is connected to the reference signal input terminal, and the output terminal of each comparator outputs one digital signal.

4. The gate driving circuit according to claim 3, characterized in that: The reference signals inputted into each of the reference signal input terminals have different magnitudes.

5. The gate driving circuit according to claim 3, characterized in that: The signal conversion unit also includes: At least two inverters, an input end of each inverter is connected to one of the digital signals, and an output end of each inverter is connected to one of the current regulating units.

6. The gate drive circuit according to any one of claims 2 to 5, characterized in that: Each of the current regulating units comprises: A multiplexer, the multiplexer comprising a first input terminal, a second input terminal, a third input terminal and an output terminal, the first input terminal is grounded, the second input terminal is connected to the input terminal of the first output stage circuit, the third input terminal is connected to one channel of the digital signal, and the output terminal of the multiplexer is connected to the input terminal of the second output stage circuit; The second output stage circuit, the output end of the second output stage circuit and the output end of the first output stage circuit are all connected to the power device, and the input end of the first output stage circuit is connected to the input signal of the gate drive circuit.

7. The gate drive circuit according to any one of claims 2 to 5, characterized in that: Each of the current regulating units comprises: a first resistor; A switch, wherein the switch is connected in parallel to two ends of the first resistor, and the switch is connected to a path of the digital signal as a control signal of the switch; The first resistors of different current regulating units are connected in series to form a resistor string, a first end of the resistor string is connected to an output end of an output stage circuit of the gate driving circuit, and a second end of the resistor string is connected to the power device.

8. The gate driving circuit according to claim 7, characterized in that: The current regulating circuit further includes: A second resistor, wherein a first end of the second resistor is connected to the output end of the output stage circuit, and a second end of the second resistor is connected to the first end of the resistor string.

9. The gate drive circuit according to any one of claims 2 to 5, characterized in that: The at least two current regulating units include: At least one first current regulating unit, each of the first current regulating units comprising: A multiplexer, the multiplexer comprising a first input terminal, a second input terminal, a third input terminal and an output terminal, the first input terminal is grounded, the second input terminal is connected to the input terminal of the first output stage circuit, the third input terminal is connected to one channel of the digital signal, and the output terminal of the multiplexer is connected to the input terminal of the second output stage circuit; The second output stage circuit, the output end of the second output stage circuit and the output end of the first output stage circuit are both connected to the power device, and the input end of the first output stage circuit is connected to the input signal of the gate drive circuit; At least one second current regulating unit, each of the second current regulating units comprising: a first resistor; A switch, wherein the switch is connected in parallel to two ends of the first resistor, and the switch is connected to a path of the digital signal as a control signal of the switch; Among them, the first resistors of different current regulating units are connected in series to form a resistor string, the first end of the resistor string is connected to the output end of the first output stage circuit or the output end of the second output stage circuit, and the second end of the resistor string is connected to the power device.

10. The gate driving circuit according to claim 1, characterized in that: The gate drive circuit further includes: The control circuit is used to disconnect the electrical connection between the temperature detection port and the temperature collection terminal of the power device when the gate drive current of the power device does not need to be adjusted.

11. A gate driver chip, characterized in that: The gate driving chip comprises the gate driving circuit according to any one of claims 1-10.

12. An electronic device, characterized in that: The electronic device comprises the gate driving chip according to claim 11.

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