A driving integrated circuit for a semiconductor high-power switching device and its application circuit

Abstract

The present invention discloses a driving integrated circuit for a semiconductor high-power switching device and its application circuit, which includes a comparison unit and a driving unit, and also includes a selection unit between the comparison unit and the driving unit; the comparison unit includes a first comparison circuit and a second comparison circuit; the driving unit includes a first driving amplifier, a second driving amplifier and a push-pull circuit, and the selection unit is used to select to input the first comparison level or the second comparison level to the second driving amplifier so as to switch the slow start mode / conventional mode of the driving control signal. Its driving integrated circuit has a slow start mode and a conventional mode. Among them, the slow start mode can effectively control the turn-on degree of the high-power switching device and limit the generation of surge large current.

Description

Technical Field

[0001] The present invention relates to the technical field of driver integrated circuits, in particular to a driver integrated circuit of a semiconductor high-power switch device and an application circuit thereof. Background Art

[0002] In the prior art, when high-power semiconductor switching devices (such as IGBTs, high-power triodes, and MOSFETs) are operating, a rectangular wave typically drives the high-power semiconductor switching devices into a switching state, and the current in the load circuit is turned on or off under the control of the high-power switching devices. Because the current energy when a high-power semiconductor switching device is turned on is relatively large, if this current exceeds the allowable value (or threshold), it can easily damage the high-power semiconductor switching device. This is especially true in the case of inductive loads. At the instant of turn-on, the current energy in the inductor is instantly released through the high-power semiconductor switching device, often resulting in excessive instantaneous surge current, which can burn out the high-power semiconductor switching device. This is often the cause of high-power semiconductor switching device damage, which in turn causes the device to malfunction. Summary of the Invention

[0003] In response to the above-mentioned defects, the purpose of the present invention is to propose a driver integrated circuit for a semiconductor high-power switching device and its application circuit, wherein the driver integrated circuit has a slow start mode and a normal mode, wherein the slow start mode can effectively control the degree of opening of the high-power switching device and limit the generation of large surge current.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] A driving integrated circuit for a semiconductor high-power switching device comprises a comparison unit and a driving unit, and further comprises a selection unit between the comparison unit and the driving unit;

[0006] The comparison unit includes a first comparison circuit and a second comparison circuit;

[0007] The first comparison circuit is used to connect an external drive control signal, compare the voltage of the drive control signal with an internal reference voltage, and generate a first comparison level;

[0008] The second comparison circuit is used to receive a detection signal output by an external sampling circuit, compare the voltage of the detection signal with the internal reference voltage, and generate a second comparison level; the sampling circuit is used to detect the voltage at the first load end of the semiconductor high-power switching device Q4;

[0009] The driving unit includes a first driving amplifier, a second driving amplifier, and a push-pull circuit. The input end of the first driving amplifier is electrically connected to the output end of the first comparison circuit. The input end of the second driving amplifier is electrically connected to the output end of the selection unit. The output end of the first driving amplifier is electrically connected to the first input end of the push-pull circuit. The output end of the second driving amplifier is electrically connected to the second input end of the push-pull circuit. The output end of the push-pull circuit is used to externally connect to the control end of the high-power semiconductor switching device Q4;

[0010] The selection unit is used to select whether to input the first comparison level or the second comparison level to the second driving amplifier, so as to switch between the soft-start mode / conventional mode of the driving control signal;

[0011] The driving unit is used to perform driving control of the high-power semiconductor switching device Q4 in the soft-start mode / conventional mode according to the selected driving control signal.

[0012] Preferably, the push-pull circuit includes a first field-effect transistor Q1, a second field-effect transistor Q2, and a third field-effect transistor Q3. The driving unit further includes a positive power supply port, a negative power supply port, and a driving output port. The output end of the first driving amplifier, the gate of the first field-effect transistor Q1, and the gate of the second field-effect transistor Q2 are electrically connected. The output end of the second driving amplifier is electrically connected to the gate of the third field-effect transistor Q3;

[0013] The drain of the first field-effect transistor Q1, the drain of the third field-effect transistor Q3, and the positive power supply port are electrically connected. The source of the first field-effect transistor Q1, the source of the third field-effect transistor Q3, and the drain of the second field-effect transistor Q2 are all electrically connected to the driving output port. The source of the second field-effect transistor Q2 is electrically connected to the negative power supply port.

[0014] Specifically, the channel type of the first field-effect transistor Q1 is the same as that of the third field-effect transistor Q3, and the channel type of the second field-effect transistor Q2 is opposite to that of the first field-effect transistor Q1;

[0015] The positive power supply port is used to externally connect to the first working power supply VCC;

[0016] The negative power supply port is used to be grounded;

[0017] The driving output port is used to externally connect to the control end of the high-power semiconductor switching device Q4.

[0018] Further, the selection unit includes a multiplexing selection port, a first selection switch S1, and a switch control module. The multiplexing selection port is used to externally connect to a selection control signal;

[0019] The first input terminal of the first selection switch S1 is electrically connected to the output terminal of the second comparison circuit. The second input terminal of the first selection switch S1 is electrically connected to the output terminal of the first comparison circuit. The output terminal of the first selection switch S1 is electrically connected to the input terminal of the second driver amplifier. The output terminal of the first selection switch S1 serves as the output terminal of the selection unit.

[0020] The input terminal of the switch control module is electrically connected to the multiplexing selection port. The output terminal of the switch control module is electrically connected to the control terminal of the first selection switch S1. The switch control module is configured to control the switching between the first input terminal and the second input terminal of the first selection switch S1 according to the level of the selection control signal, so as to select whether to input the first comparison level or the second comparison level to the second driver amplifier.

[0021] Optionally, the comparison unit further includes a reference voltage module, which is configured to output the preset reference voltage.

[0022] The first comparison circuit includes a first comparator U1 and a first input port, which is used for externally connecting a drive control signal. The positive input terminal of the first comparator U1 is electrically connected to the first input port. The negative input terminal of the first comparator U1 is electrically connected to the output terminal of the reference voltage module. The output terminal of the first comparator U1 is electrically connected to the second input terminal of the first selection switch S1. The output terminal of the first comparator U1 serves as the output terminal of the first comparison circuit.

[0023] More specifically, the second comparison circuit includes a second comparator U2 and a second input port, which is used for externally connecting the detection signal output by the sampling circuit. The negative input terminal of the second comparator U2 is electrically connected to the second input port. The positive input terminal of the second comparator U2 is electrically connected to the output terminal of the reference voltage module. The output terminal of the second comparator U2 is electrically connected to the first input terminal of the first selection switch S1. The output terminal of the second comparator U serves as the output terminal of the second comparison circuit.

[0024] Further, in the push-pull circuit, when the first field-effect transistor Q1, the second field-effect transistor Q2, and the third field-effect transistor Q3 are all turned on, the output internal resistance of the push-pull circuit at the high level is:

[0025]

[0026] When the third field-effect transistor Q3 is turned off, and the first field-effect transistor Q1 and the second field-effect transistor Q2 are turned on, the output internal resistance of the push-pull circuit at the high level is R 内 = R Q1 , and the output internal resistance of the push-pull circuit at the low level is R内 = R Q2 ;

[0027] Among them, the equivalent resistance R of the third field effect transistor Q3 Q3 is less than the equivalent resistance R of the first field effect transistor Q1 Q1 , and R Q2 is the equivalent resistance of the second field effect transistor Q2.

[0028] Optionally, an application circuit includes a driving integrated circuit of the semiconductor high-power switching device, the sampling circuit, a driving controller MCU, an inductive load circuit, a second selection switch S2, and the semiconductor high-power switching device Q4;

[0029] The input end of the sampling circuit and the output end of the inductive load circuit are both electrically connected to the first load end of the semiconductor high-power switching device Q4. The second load end of the semiconductor high-power switching device Q4 is grounded, and the control end of the semiconductor high-power switching device Q4 is electrically connected to the driving output port;

[0030] The output end of the driving controller MCU is electrically connected to the first input port of the first comparison circuit;

[0031] The output end of the sampling circuit is electrically connected to the second input port of the second comparison circuit;

[0032] The first input end of the second selection switch S2 is connected to a high level, the second input end of the second selection switch S2 is grounded, and the output end of the second selection switch S2 is electrically connected to the multiplexing selection port.

[0033] Further, the sampling circuit includes a resistor R3 and a resistor R4, the inductive load circuit includes an inductor L1 and a capacitor C1. One end of the resistor R3, one end of the capacitor C1, and one end of the inductor L1 are all electrically connected to the first load end of the semiconductor high-power switching device Q4. The other end of the resistor R3 and one end of the resistor R4 are both electrically connected to the second input port of the second comparison circuit, and the other end of the resistor R4 is grounded;

[0034] The other end of the capacitor C1 and the other end of the inductor L1 are both electrically connected to the second working power supply VDD.

[0035] The above technical solution has the following beneficial effects:

[0036] The driving integrated circuit of the semiconductor high-power switching device is provided with a selection unit. Through the selection unit, the soft-start mode / conventional mode can be switched, that is, it has both the soft-start mode and the conventional mode, which is more flexible and general. The driving control signal forms a first comparison level through the first comparison circuit, and the first comparison level controls the conduction or cut-off of the semiconductor high-power switching device Q4 after being amplified by the first driving amplifier and the push-pull circuit.

[0037] The second comparison level can change the output internal resistance when the push-pull circuit is at a high level, so that the integrated circuit outputs with a high internal resistance. The output level slowly charges the parasitic capacitance C2 on the control terminal and the second load terminal of the semiconductor high-power switching device Q4 through a relatively large internal resistance, so that the voltage for controlling the opening of the semiconductor high-power switching device Q4 slowly rises. For example, Figure 1 in the rising edge of the rectangular wave forms an arc angle, achieving the effect of soft start. Thus, by selecting different voltages to control the opening of the buffer function at an appropriate time, the rectangular wave slowly rises to form an arc, and the buffer function is turned off when the energy is released below the threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is the driving integrated circuit diagram of the semiconductor high-power switching device of one embodiment of the present invention;

[0039] Figure 2 is the application circuit diagram of the driving integrated circuit of one embodiment of the present invention.

[0040] Among them: comparison unit 1; selection unit 2; driving unit 3; first comparison circuit 11; second comparison circuit 12; sampling circuit 4; first driving amplifier 31; second driving amplifier 32; push-pull circuit 33; first field effect transistor Q1; second field effect transistor Q2; third field effect transistor Q3; semiconductor high-power switching device Q4; positive power supply port 34; negative power supply port 35; driving output port 36; multiplexing selection port 21; first selection switch S1; switch control module 22; reference voltage module 13; first comparator U1; first input port 111; second comparator U2; second input port 121; driving controller MCU; inductive load circuit 5; second selection switch S2; resistor R3; resistor R4; inductor L1; capacitor C1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0042] The following will be combined with Figures 1 to 2, a driving integrated circuit of a semiconductor high-power switching device according to an embodiment of the present invention and its application circuit.

[0043] Embodiment 1

[0044] The driving integrated circuit of the semiconductor high-power switching device in this embodiment, as Figure 1 shown, includes a comparison unit 1 and a driving unit 3, and a selection unit 2 is further included between the comparison unit 1 and the driving unit 3;

[0045] The comparison unit 1 includes a first comparison circuit 11 and a second comparison circuit 12;

[0046] The first comparison circuit 11 is used to externally connect a driving control signal, compare the voltage of the driving control signal with a preset reference voltage, and generate a first comparison level;

[0047] The second comparison circuit 12 is used to externally connect a detection signal output by a sampling circuit 4, compare the voltage of the detection signal with the preset reference voltage, and generate a second comparison level; the sampling circuit 4 is used to detect the voltage at the first load terminal of the semiconductor high-power switching device Q4;

[0048] The driving unit 3 includes a first driving amplifier 31, a second driving amplifier 32, and a push-pull circuit 33. The input end of the first driving amplifier 31 is electrically connected to the output end of the first comparison circuit 11. The input end of the second driving amplifier 32 is electrically connected to the output end of the selection unit 2. The output end of the first driving amplifier 31 is electrically connected to the first input end of the push-pull circuit 33. The output end of the second driving amplifier 32 is electrically connected to the second input end of the push-pull circuit 33. The output end of the push-pull circuit 33 is used to externally connect the control end of the semiconductor high-power switching device Q4;

[0049] The selection unit 2 is used to select to input the first comparison level or the second comparison level to the second driving amplifier 32 to switch between the soft start mode / conventional mode of the driving control signal;

[0050] The driving unit 3 is used to perform driving control of the semiconductor high-power switching device Q4 in the soft start mode / conventional mode according to the selected driving control signal.

[0051] The driving integrated circuit of the semiconductor high-power switching device is provided with a selection unit 2, and the soft start mode / conventional mode can be switched through the selection unit 2, that is, it has both the soft start mode and the conventional mode, which is more flexible and general. When applied, a selection circuit can be externally connected, such as a selection switch, etc.; the driving control signal is usually such as Figure 1The rectangular wave shown, wherein the drive control signal forms a first comparison level through the first comparison circuit 11, and after being amplified by the first drive amplifier 31 and the push-pull circuit 33, the first comparison level controls the conduction or cutoff of the high-power semiconductor switch device Q4;

[0052] The input terminal of the second comparison circuit 12 is externally connected to a detection signal, that is, the voltage at the first load terminal of the high-power semiconductor switch device Q4 is detected. Since the first load terminal of the high-power semiconductor switch device Q4 is usually connected to the energy release terminal of the inductive load circuit 5 to detect the energy voltage of the high-power semiconductor switch device Q4, the detection signal forms a second comparison level through the second comparison circuit 12, and after being amplified by the second drive amplifier 32 and the push-pull circuit 33, the second comparison level controls the conduction or cutoff of the high-power semiconductor switch device Q4. More specifically, the second comparison level can change the output internal resistance when the push-pull circuit 33 is at a high level, enabling the integrated circuit to output with a high internal resistance. The output level slowly charges the parasitic capacitance C2 at the control terminal and the second load terminal of the high-power semiconductor switch device Q4 through a relatively large internal resistance, causing the voltage for controlling the high-power semiconductor switch device Q4 to turn on to rise slowly. For example, Figure 1 in the rising edge of the rectangular wave forms an arc angle, achieving the effect of soft start. The parasitic capacitance is a capacitance that naturally occurs during the manufacturing of the high-power semiconductor switch device Q4.

[0053] Therefore, when the second comparison level is selected to be input to the second drive amplifier 32, the high-power semiconductor switch device Q4 is in the soft start mode; when the first comparison level is selected to be input to the second drive amplifier 32, the high-power semiconductor switch device Q4 is in the normal mode, that is, a drive mode without the soft start effect.

[0054] It should be noted that in this embodiment, the high-power semiconductor switch device Q4 is Figure 1 the IGBT shown. Among them, the first load terminal of the high-power semiconductor switch device Q4 is the collector of the IGBT, the second load terminal of the high-power semiconductor switch device Q4 is the emitter of the IGBT, and the control terminal of the high-power semiconductor switch device Q4 is the gate of the IGBT. Of course, the high-power semiconductor switch device Q4 in this embodiment can also be a high-power triode, MOSFET, etc., which is determined by the actual usage requirements and is not limited herein.

[0055] Furthermore, as Figure 1As shown, the push-pull circuit 33 includes a first field-effect transistor Q1, a second field-effect transistor Q2, and a third field-effect transistor Q3. The driving unit 3 further includes a positive power supply port 34, a negative power supply port 35, and a driving output port 36. The output terminal of the first driving amplifier 31, the gate of the first field-effect transistor Q1, and the gate of the second field-effect transistor Q2 are electrically connected. The output terminal of the second driving amplifier 32 and the gate of the third field-effect transistor Q3 are electrically connected;

[0056] The drain of the first field-effect transistor Q1, the drain of the third field-effect transistor Q3, and the positive power supply port 34 are electrically connected. The source of the first field-effect transistor Q1, the source of the third field-effect transistor Q3, and the drain of the second field-effect transistor Q2 are all electrically connected to the driving output port 36. The source of the second field-effect transistor Q2 is electrically connected to the negative power supply port 35.

[0057] Among them, the positive power supply port 34 is used to externally connect a first working power supply VCC;

[0058] The negative power supply port 35 is used to be grounded;

[0059] The driving output port 36 is used to externally connect the control terminal of the semiconductor high-power switching device Q4.

[0060] The channel types of the first field-effect transistor Q1 and the third field-effect transistor Q3 are the same, and the channel type of the second field-effect transistor Q2 is opposite to that of the first field-effect transistor Q1. The same channel type means that they are both P-channel field-effect transistors or both N-channel field-effect transistors; the opposite channel type means that when one is a P-channel field-effect transistor, the other is an N-channel field-effect transistor, or when one is an N-channel field-effect transistor, the other is a P-channel field-effect transistor.

[0061] For example, as Figure 1 shown, both the first field-effect transistor Q1 and the third field-effect transistor Q3 are P-channel field-effect transistors, and the second field-effect transistor Q2 is an N-channel field-effect transistor; or for another example, both the first field-effect transistor Q1 and the third field-effect transistor Q3 are N-channel field-effect transistors, and the second field-effect transistor Q2 is a P-channel field-effect transistor. According to the actual application requirements, different combinations of channel types are selected.

[0062] Thus, the first comparison level is amplified by the first driving amplifier 31 and then controls the conduction or cutoff of the semiconductor high-power switching device Q4 through the push-pull circuit 33 composed of the first field-effect transistor Q1 and the second field-effect transistor Q2.

[0063] When the selection unit 2 selects to input the second comparison level to the second drive amplifier 32, the second comparison level controls the on or off of the third field-effect transistor Q3: For example, the second comparison circuit 12 is set such that when the voltage of the detection signal is higher than the reference voltage, the second comparison level is a low level. Then, after being amplified by the second drive amplifier 32, it controls the third field-effect transistor Q3 to turn off. At this time, the third field-effect transistor Q3 is ineffective, and the output of the push-pull circuit 33 is determined by the first field-effect transistor Q1 and the second field-effect transistor Q2. When the drive output port 36 outputs a high level, the internal resistance of the push-pull circuit 33 is large, and the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is slowly charged, causing the voltage for controlling the semiconductor high-power switching device Q4 to turn on to rise slowly, that is, the semiconductor high-power switching device Q4 is in a slow (incomplete) conduction state;

[0064] When the voltage of the detection signal is lower than the reference voltage, the second comparison level is a high level. Then, after being amplified by the second drive amplifier 32, it controls the third field-effect transistor Q3 to turn on. At this time, the third field-effect transistor Q3 is in parallel with the first field-effect transistor Q1, making the internal resistance of the push-pull circuit 33 small when the drive output port 36 outputs a high level. The drive current of the semiconductor high-power switching device Q4 increases, and the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is quickly charged. The control terminal voltage of the semiconductor high-power switching device Q4 rises rapidly and tends to be flat, and the semiconductor high-power switching device Q4 enters a fully conducting state. The fully turned-on state is an ideal state with relatively small losses for the semiconductor high-power switching device Q4. Thus, by selecting different voltages, the buffer function is controlled to be turned on at an appropriate time to make the rectangular wave rise slowly to form an arc, and the buffer function is turned off when the energy is released below the threshold.

[0065] The above is the working process of the soft-start mode. When the selection unit 2 selects to input the first comparison level to the second drive amplifier 32, the first comparison level controls the on or off of the third field-effect transistor Q3, and the drive integrated circuit can be used as an ordinary drive circuit without soft start, directly serving as a driver for the conventional semiconductor high-power switching device Q4, without the soft-start function, and switches to the conventional mode of operation.

[0066] The positive power supply port 34 is used to externally connect the first working power supply VCC and is the power input port of the drive integrated circuit. The negative power supply port 35 is used to ground and is the negative power input terminal of the drive integrated circuit and also the power ground terminal.

[0067] Optionally, the selection unit 2 includes a multiplexing selection port 21, a first selection switch S1, and a switch control module 22. The multiplexing selection port 21 is used to externally connect a selection control signal;

[0068] The first input terminal of the first selection switch S1 is electrically connected to the output terminal of the second comparison circuit 12, the second input terminal of the first selection switch S1 is electrically connected to the output terminal of the first comparison circuit 11, the output terminal of the first selection switch S1 is electrically connected to the input terminal of the second drive amplifier 32, and the output terminal of the first selection switch S1 serves as the output terminal of the selection unit 2;

[0069] The input terminal of the switch control module 22 is electrically connected to the multiplexing selection port 21, the output terminal of the switch control module 22 is electrically connected to the control terminal of the first selection switch S1, and the switch control module 22 is configured to control the switching between the first input terminal and the second input terminal of the first selection switch S1 according to the level of the selection control signal, so as to select to input the first comparison level or the second comparison level to the second drive amplifier 32.

[0070] For example, when the selection control signal is at a high level, control the connection between the first input terminal of the first selection switch S1 and its output terminal, input the second comparison level to the second drive amplifier 32, and enter the soft start mode; when the selection control signal is at a low level, control the connection between the second input terminal of the first selection switch S1 and its output terminal, input the first comparison level to the second drive amplifier 32, and enter the normal mode.

[0071] It should be noted that in this embodiment, the first input terminal of the first selection switch S1 is Figure 1 pin 1 of the first selection switch S1 shown, the second input terminal of the first selection switch S1 is Figure 1 pin 2 of the first selection switch S1 shown, and the output terminal of the first selection switch S1 is Figure 1 pin 3 of the first selection switch S1 shown. The switch control module 22 is an existing conventional selection switch control module, which will not be elaborated here.

[0072] Specifically, the comparison unit 1 further includes a reference voltage module 13, and the reference voltage module 13 is configured to output the preset reference voltage;

[0073] The first comparison circuit 11 includes a first comparator U1 and a first input port 111. The first input port 111 is used for externally connecting a drive control signal. The positive input terminal of the first comparator U1 is electrically connected to the first input port 111, the negative input terminal of the first comparator U1 is electrically connected to the output terminal of the reference voltage module 13, the output terminal of the first comparator U1 is electrically connected to the second input terminal of the first selection switch S1, and the output terminal of the first comparator U1 serves as the output terminal of the first comparison circuit 11.

[0074] Thus, when the voltage of the drive control signal is higher than the reference voltage of the first comparator U1, the first comparison level output by the first comparator U1 is at a high level. After being driven by the first drive amplifier 31, it drives the push-pull output circuit composed of the internal first field-effect transistor Q1 and the second field-effect transistor Q2, and then outputs a high level through the drive output port 36 to drive the semiconductor high-power switching device Q4 to turn on;

[0075] Similarly, when the voltage of the drive control signal is lower than the reference voltage of the first comparator U1, the first comparison level output by the first comparator U1 is at a low level. After being driven by the first drive amplifier 31, it drives the push-pull output circuit composed of the internal first field-effect transistor Q1 and the second field-effect transistor Q2, and then outputs a low level through the drive output port 36 to drive the semiconductor high-power switching device Q4 to turn off.

[0076] More specifically, the second comparison circuit 12 includes a second comparator U2 and a second input port 121. The second input port 121 is used to externally connect the detection signal output by the sampling circuit. The negative input terminal of the second comparator U2 is electrically connected to the second input port 121. The positive input terminal of the second comparator U2 is electrically connected to the output terminal of the reference voltage module 13. The output terminal of the second comparator U2 is electrically connected to the first input terminal of the first selection switch S1. The output terminal of the second comparator U2 serves as the output terminal of the second comparison circuit 12.

[0077] Thus, when the voltage of the detection signal is higher than the reference voltage of the second comparator U2, the second comparison level output by the second comparator U2 is at a low level. Through the selection of the first selection switch S1 (assuming that the 1-pin and 3-pin of the first selection switch S1 are connected at this time), after being amplified by the second drive amplifier 32, it controls the third field-effect transistor Q3 to turn off. At this time, the third field-effect transistor Q3 does not work. The output of the push-pull circuit 33 is determined by the first field-effect transistor Q1 and the second field-effect transistor Q2. When the drive output port 36 outputs a high level, the internal resistance of the push-pull circuit 33 is large, and the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is slowly charged, causing the voltage for controlling the semiconductor high-power switching device Q4 to turn on to rise slowly, that is, the semiconductor high-power switching device Q4 is in a slow (incomplete) conduction state;

[0078] When the voltage of the detection signal is lower than the reference voltage of the second comparator U2, the second comparison level output by the second comparator U2 is at a high level. After being amplified by the second drive amplifier 32, it controls the third field-effect transistor Q3 to conduct. At this time, the third field-effect transistor Q3 is in parallel with the first field-effect transistor Q1, so that when the drive output port 36 outputs a high level, the internal resistance of the push-pull circuit 33 is small, the drive current of the semiconductor high-power switching device Q4 increases, the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is quickly charged, the control terminal voltage of the semiconductor high-power switching device Q4 quickly rises and tends to be flat, and the semiconductor high-power switching device Q4 enters the fully-conducted state. The fully-conducted state is an ideal state with relatively small losses for the semiconductor high-power switching device Q4.

[0079] It should be noted that the selection range of the reference voltage can be, but is not limited to, 0.1V to 4.9V. The first comparator U1 and the second comparator U2 share a reference voltage. The input signals of the first comparator U1 and the second comparator U2 are compared with the reference voltage and then output control levels. The first comparator U1 has its positive input terminal input, so when the input voltage is higher than the reference voltage, the control level output by the first comparator U1 is at a high level. The second comparator U2 has its negative input terminal input, so when the input voltage is lower than the reference voltage, the control level output by the second comparator U2 is at a high level, and vice versa.

[0080] Furthermore, in the push-pull circuit 33, when the first field-effect transistor Q1, the second field-effect transistor Q2, and the third field-effect transistor Q3 are all conducting, the output internal resistance of the push-pull circuit 33 at a high level is:

[0081]

[0082] When the third field-effect transistor Q3 is turned off, and the first field-effect transistor Q1 and the second field-effect transistor Q2 are conducting, the output internal resistance of the push-pull circuit 33 at a high level is R 内 =R Q1 The output internal resistance of the push-pull circuit 33 at a low level is R 内 =R Q2 ;

[0083] Among them, the equivalent resistance R Q3 of the third field-effect transistor Q3 is less than the equivalent resistance R Q1 of the first field-effect transistor Q1, and R Q2 is the equivalent resistance of the second field-effect transistor Q2.

[0084] That is, the first field-effect transistor Q1, the second field-effect transistor Q2, and the third field-effect transistor Q3 form a push-pull circuit 33 with a variable output internal resistance. Among them, the second field-effect transistor Q2 is used as a pull-down transistor, and the equivalent resistance R Q2is relatively small. The first field effect transistor Q1 is used as a pull-up transistor, and the equivalent resistance R of the first field effect transistor Q1 Q1 is relatively large. The third field effect transistor Q3 is also used as a pull-up transistor, and the equivalent resistance R of the third field effect transistor Q3 Q3 is relatively small. In some embodiments, the equivalent resistance R Q2 and the equivalent resistance R Q3 may have a similar resistance value range, and are much smaller than the resistance value range of the equivalent resistance R Q1 .

[0085] When the third field effect transistor Q3 is turned off and the first field effect transistor Q1 and the second field effect transistor Q2 are turned on, the output internal resistance of the push-pull circuit 33 at high level is R 内 = R Q1 , and the output internal resistance of the push-pull circuit 33 at low level is R 内 = R Q2 . The output internal resistance is large, and the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is slowly charged, so that the voltage for controlling the semiconductor high-power switching device Q4 to turn on rises slowly. As shown in Figure 1 , an arc angle is formed at the rising edge of the rectangular wave in the figure, achieving the effect of soft start.

[0086] When the third field effect transistor Q3 is turned on, the third field effect transistor Q3 is in parallel with the first field effect transistor Q1. The output internal resistance of the push-pull circuit 33 at high level after parallel connection is . The output internal resistance becomes smaller, the drive current of the semiconductor high-power switching device Q4 increases, the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is quickly charged, the control terminal voltage of the semiconductor high-power switching device Q4 rises rapidly and tends to be flat, and the semiconductor high-power switching device Q4 enters the fully conducting state.

[0087] The buffering function uses two MOS power transistors with the same channel type (i.e., the third field effect transistor Q3 and the first field effect transistor Q1). When the third field effect transistor Q3 and the first field effect transistor Q1 are turned on and in parallel, the output internal resistance of the push-pull circuit 33 is reduced. When the parallel connection is cancelled and a single transistor is used for operation, the internal resistance is increased, which plays a role in reducing the output current and buffering the start-up;

[0088] In addition, according to the manufacturing process of semiconductor devices, MOSFETs can be manufactured according to resistance values. Therefore, by changing the resistance value, the output current is changed, the charging current of the parasitic capacitance of the semiconductor high-power switching device Q4 is changed, and thus the voltage rising speed at the control terminal of the semiconductor high-power switching device Q4 is changed, achieving the effect of slowly turning on the switch.

[0089] Embodiment 2

[0090] The application circuit of this embodiment is as shown in Figure 2As shown, it includes the drive integrated circuit of the semiconductor high-power switching device described in Embodiment 1, the sampling circuit 4, the drive controller MCU, the inductive load circuit 5, the second selection switch S2, and the semiconductor high-power switching device Q4;

[0091] The input end of the sampling circuit 4 and the output end of the inductive load circuit 5 are both electrically connected to the first load end of the semiconductor high-power switching device Q4. The second load end of the semiconductor high-power switching device Q4 is grounded, and the control end of the semiconductor high-power switching device Q4 is electrically connected to the drive output port 36;

[0092] The output end of the drive controller MCU is electrically connected to the first input port 111 of the first comparison circuit 11;

[0093] The output end of the sampling circuit 4 is electrically connected to the second input port 121 of the second comparison circuit 12;

[0094] The first input end of the second selection switch S2 is connected to a high level, the second input end of the second selection switch S2 is grounded, and the output end of the second selection switch S2 is electrically connected to the multiplexing selection port 21.

[0095] The application circuit detects the voltage at the energy release end of the inductive load circuit 5 through the sampling circuit 4 and inputs it to the second input port 121 of the drive integrated circuit. The output end of the drive controller MCU inputs a drive control signal to the first input port 111;

[0096] The second selection switch S2 outputs a selection control signal to the multiplexing selection port 21. When the first input end of the second selection switch S2 is connected to its output end, the selection control signal is a high level; when the second input end of the second selection switch S2 is connected to its output end, the selection control signal is a low level.

[0097] It should be noted that in this embodiment, the first input end of the second selection switch S2 is Figure 1 the pin 1 of the second selection switch S2 shown, the second input end of the second selection switch S2 is Figure 1 the pin 2 of the second selection switch S2 shown, and the output end of the second selection switch S2 is Figure 1 the pin 3 of the second selection switch S2 shown.

[0098] Specifically, the sampling circuit 4 includes a resistor R3 and a resistor R4, the inductive load circuit 5 includes an inductor L1 and a capacitor C1, one end of the resistor R3, one end of the capacitor C1, and one end of the inductor L1 are all electrically connected to the first load terminal of the semiconductor high-power switching device Q4, the other end of the resistor R3 and one end of the resistor R4 are both electrically connected to the second input port 121 of the second comparison circuit 12, and the other end of the resistor R4 is grounded;

[0099] The other end of the capacitor C1 and the other end of the inductor L1 are both electrically connected to the second working power supply VDD.

[0100] The resistor R3 and the resistor R4 play a voltage-dividing role, and the voltage detected by the resistor R3 at the first load terminal of the semiconductor high-power switching device Q4 is connected to the second input port 121 of the driving integrated circuit through the resistor R4 for voltage division. The inductive load circuit 5 includes an inductor L1 and a capacitor C1. It should be noted that the specific structural composition of the inductive load circuit 5 is determined by the circuit structure in the application scenario of the present invention and is not limited herein.

[0101] The working process of the application circuit is as follows:

[0102] The drive controller MCU inputs a drive control signal to the first comparison circuit 11. When the voltage of the drive control signal is higher than the reference voltage of the first comparator U1, the first comparison level output by the first comparator U1 is a high level, which drives the push-pull output circuit composed of the internal first field-effect transistor Q1 and the second field-effect transistor Q2 through the first drive amplifier 31, and then outputs a high level through the drive output port 36 to drive the semiconductor high-power switching device Q4 to turn on;

[0103] Similarly, when the voltage of the drive control signal is lower than the reference voltage of the first comparator U1, the first comparison level output by the first comparator U1 is a low level, which drives the push-pull output circuit composed of the internal first field-effect transistor Q1 and the second field-effect transistor Q2 through the first drive amplifier 31, and then outputs a low level through the drive output port 36 to drive the semiconductor high-power switching device Q4 to turn off.

[0104] The second selection switch S2 outputs a selection control signal to the multiplexing selection port 21, and the selection control signal controls the switching between the first input terminal and the second input terminal of the first selection switch S1 to select whether to input the first comparison level or the second comparison level to the second drive amplifier 32.

[0105] When the slow start mode is selected (the 1-pin and 3-pin of the first selection switch S1 are connected), when the sampling circuit 4 detects that the voltage at the first load terminal of the semiconductor high-power switching device Q4 is relatively high, the voltage divided by the resistor R3 and the resistor R4 is higher than the reference voltage, and the second comparison level output by the second comparator U2 is a low level. After being amplified by the second drive amplifier 32, it controls the third field-effect transistor Q3 to turn off. At this time, the third field-effect transistor Q3 does not work, and the output of the push-pull circuit 33 is determined by the first field-effect transistor Q1 and the second field-effect transistor Q2. When the drive output port 36 outputs a high level, the internal resistance of the push-pull circuit 33 is large, and the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is slowly charged, so that the voltage for controlling the opening of the semiconductor high-power switching device Q4 rises slowly, that is, the semiconductor high-power switching device Q4 is in a slow (incomplete) conduction state;

[0106] When the sampling circuit 4 detects that the voltage at the first load terminal of the semiconductor high-power switching device Q4 is relatively low, the voltage divided by the resistor R3 and the resistor R4 is lower than the reference voltage, and the second comparison level output by the second comparator U2 is a high level. After being amplified by the second drive amplifier 32, it controls the third field-effect transistor Q3 to turn on. At this time, the third field-effect transistor Q3 is connected in parallel with the first field-effect transistor Q1, so that when the drive output port 36 outputs a high level, the internal resistance of the push-pull circuit 33 is small, the drive current of the semiconductor high-power switching device Q4 increases, the parasitic capacitance C2 of the semiconductor high-power switching device Q4 is quickly charged, the control terminal voltage of the semiconductor high-power switching device Q4 rises rapidly and tends to be flat, and the semiconductor high-power switching device Q4 enters the fully-conducted state. The fully-conducted state is an ideal state with relatively small losses of the semiconductor high-power switching device Q4. Thus, by selecting different voltages, the buffer function is controlled to be turned on at an appropriate time to make the rectangular wave rise slowly to form an arc, and the buffer function is turned off when the energy is released below the threshold.

[0107] When the second selection switch S2 selects to input the first comparison level to the second drive amplifier 32, the conduction or cut-off of the third field-effect transistor Q3 is controlled by the first comparison level, and the drive integrated circuit can be used as an ordinary drive circuit without slow start, directly as a driver for the conventional semiconductor high-power switching device Q4, without the slow start function, and switches to the conventional mode for operation.

[0108] For those of ordinary skill in the art, other components and operations of the drive integrated circuit of the semiconductor high-power switching device and its application circuit according to the embodiments of the present invention are known, and will not be described in detail here.

[0109] In the description of this specification, the descriptions referring to the terms "embodiment", "example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0110] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A driving integrated circuit for a semiconductor high-power switching device, comprising a comparison unit and a driving unit, characterized in that: A selection unit is further included between the comparison unit and the drive unit; The comparison unit includes a first comparison circuit and a second comparison circuit; The first comparison circuit is used to externally connect a drive control signal, compare the voltage of the drive control signal with a built-in reference voltage, and generate a first comparison level; The second comparison circuit is used to externally connect a detection signal output by a sampling circuit, compare the voltage of the detection signal with the built-in reference voltage, and generate a second comparison level; The sampling circuit is used to detect the voltage at the first load terminal of the semiconductor high-power switching device Q4; The drive unit includes a first drive amplifier, a second drive amplifier, and a push-pull circuit. The input end of the first drive amplifier is electrically connected to the output end of the first comparison circuit. The input end of the second drive amplifier is electrically connected to the output end of the selection unit. The output end of the first drive amplifier is electrically connected to the first input end of the push-pull circuit. The output end of the second drive amplifier is electrically connected to the second input end of the push-pull circuit. The output end of the push-pull circuit is used to externally connect the control end of the semiconductor high-power switching device Q4; The selection unit is used to select to input the first comparison level or the second comparison level to the second drive amplifier to switch between the soft start mode / conventional mode of the drive control signal; The drive unit is used to perform drive control of the semiconductor high-power switching device Q4 in the soft start mode / conventional mode according to the selected drive control signal; The push-pull circuit includes a first field-effect transistor Q1, a second field-effect transistor Q2, and a third field-effect transistor Q3. The drive unit further includes a positive power supply port, a negative power supply port, and a drive output port. The output end of the first drive amplifier, the gate of the first field-effect transistor Q1, and the gate of the second field-effect transistor Q2 are electrically connected. The output end of the second drive amplifier is electrically connected to the gate of the third field-effect transistor Q3; The drain of the first field-effect transistor Q1, the drain of the third field-effect transistor Q3, and the positive power supply port are electrically connected. The source of the first field-effect transistor Q1, the source of the third field-effect transistor Q3, and the drain of the second field-effect transistor Q2 are all electrically connected to the drive output port. The source of the second field-effect transistor Q2 is electrically connected to the negative power supply port.

2. The driving integrated circuit of the high-power semiconductor switching device according to claim 1, characterized in that: The channel type of the first field-effect transistor Q1 is the same as that of the third field-effect transistor Q3, and the channel type of the second field-effect transistor Q2 is opposite to that of the first field-effect transistor Q1; The positive power supply port is used to externally connect the first working power supply VCC; The negative power supply port is used to be grounded; The drive output port is used to externally connect the control end of the semiconductor high-power switching device Q4.

3. The driving integrated circuit of the semiconductor high-power switching device according to claim 1, wherein: The selection unit includes a multiplexing selection port, a first selection switch S1, and a switch control module. The multiplexing selection port is used to externally connect a selection control signal; The first input terminal of the first selection switch S1 is electrically connected to the output terminal of the second comparison circuit, the second input terminal of the first selection switch S1 is electrically connected to the output terminal of the first comparison circuit, the output terminal of the first selection switch S1 is electrically connected to the input terminal of the second drive amplifier, and the output terminal of the first selection switch S1 serves as the output terminal of the selection unit; The input terminal of the switch control module is electrically connected to the multiplexing selection port, the output terminal of the switch control module is electrically connected to the control terminal of the first selection switch S1, and the switch control module is configured to control the switching between the first input terminal and the second input terminal of the first selection switch S1 according to the level of the selection control signal, so as to select whether to input the first comparison level or the second comparison level to the second drive amplifier.

4. The driving integrated circuit of the high-power semiconductor switching device according to claim 3, characterized in that: The comparison unit further includes a reference voltage module, and the reference voltage module is configured to output the preset reference voltage; The first comparison circuit includes a first comparator U1 and a first input port, the first input port is used for externally connecting a drive control signal, the positive input terminal of the first comparator U1 is electrically connected to the first input port, the negative input terminal of the first comparator U1 is electrically connected to the output terminal of the reference voltage module, the output terminal of the first comparator U1 is electrically connected to the second input terminal of the first selection switch S1, and the output terminal of the first comparator U1 serves as the output terminal of the first comparison circuit.

5. The driving integrated circuit of the semiconductor high-power switching device according to claim 4, characterized in that: The second comparison circuit includes a second comparator U2 and a second input port, the second input port is used for externally connecting the detection signal output by the sampling circuit, the negative input terminal of the second comparator U2 is electrically connected to the second input port, the positive input terminal of the second comparator U2 is electrically connected to the output terminal of the reference voltage module, the output terminal of the second comparator U2 is electrically connected to the first input terminal of the first selection switch S1, and the output terminal of the second comparator U2 serves as the output terminal of the second comparison circuit.

6. The driving integrated circuit of the high-power semiconductor switching device according to claim 1, characterized in that: In the push-pull circuit, when the first field-effect transistor Q1, the second field-effect transistor Q2, and the third field-effect transistor Q3 are all turned on, the output internal resistance of the push-pull circuit at high level is: ； When the third field effect transistor Q3 is turned off and the first field effect transistor Q1 and the second field effect transistor Q2 are turned on, the output internal resistance of the push-pull circuit at high level is , and the output internal resistance of the push-pull circuit at low level is ; Among them, the equivalent resistance of the third field effect transistor Q3 is less than the equivalent resistance of the first field effect transistor Q1 , and is the equivalent resistance of the second field effect transistor Q2.

7. An application circuit, characterized in that: Including a drive integrated circuit for the semiconductor high-power switching device according to any one of claims 1 to 6, the sampling circuit, a drive controller MCU, an inductive load circuit, a second selection switch S2, and the semiconductor high-power switching device Q4; The input terminal of the sampling circuit and the output terminal of the inductive load circuit are both electrically connected to the first load terminal of the semiconductor high-power switching device Q4, the second load terminal of the semiconductor high-power switching device Q4 is grounded, and the control terminal of the semiconductor high-power switching device Q4 is electrically connected to the drive output port; The output terminal of the drive controller MCU is electrically connected to the first input port of the first comparison circuit; The output terminal of the sampling circuit is electrically connected to the second input port of the second comparison circuit; The first input terminal of the second selection switch S2 is connected to a high level, the second input terminal of the second selection switch S2 is grounded, and the output terminal of the second selection switch S2 is electrically connected to the multiplexing selection port.

8. The application circuit according to claim 7, characterized in that: The sampling circuit includes a resistor R3 and a resistor R4. The inductive load circuit includes an inductor L1 and a capacitor C1. One end of the resistor R3, one end of the capacitor C1, and one end of the inductor L1 are all electrically connected to the first load terminal of the semiconductor high-power switching device Q4. The other end of the resistor R3 and one end of the resistor R4 are both electrically connected to the second input port of the second comparison circuit. The other end of the resistor R4 is grounded; The other end of the capacitor C1 and the other end of the inductor L1 are both electrically connected to the second working power supply VDD.

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