Electronic circuit, driving method of multi-gate element, and electronic system

Abstract

An electronic circuit according to an embodiment includes: a control circuit that controls a rising timing of a first pulse signal applied to a first control gate electrode of a multi-gate element; and a comparison circuit that obtains a comparison result between a voltage associated with a voltage between the first electrode and the second electrode of the multi-gate element and the first voltage or the second voltage. The control circuit acquires, on the basis of the comparison result, a transition time for a voltage associated with a voltage between the first electrode and the second electrode when the multi-gate element is turned on from below the first voltage to below the second voltage, and adjusts the rising timing of the second pulse signal so as to reduce the transition time.

Description

[0001] This application is based on Japanese Patent Application No. 2024-133372 (Filing Date: August 8, 2024) and claims priority from it. This application incorporates the entire contents of the application by reference. TECHNICAL FIELD

[0002] The present embodiment relates to an electronic circuit, a driving method of a multi-gate element, and an electronic system. BACKGROUND

[0003] A multi-gate IGBT (Insulated Gate Bipolar Transistor) is known, which has a plurality of gate electrodes, and by a pattern of pulse signals applied to each of the gate electrodes, it is possible to reduce on-state loss and off-state loss. The multi-gate IGBT has, in addition to a usual electrode for on-state control, a control gate electrode for increasing and decreasing the accumulated carrier density. By controlling the pattern of the pulse signals applied to the control gate electrode so as to increase the accumulated carrier density at the time of turning on to instantaneously increase the current flowing therethrough, and to decrease the accumulated carrier density in stages at the time of turning off, it is possible to reduce the switching loss of the element. SUMMARY

[0004] The present embodiment aims to provide an electronic circuit, a driving method of a multi-gate element, and an electronic system that reduce the on-state loss of a multi-gate element.

[0005] In order to solve the above problem, the electronic circuit of the present embodiment includes a control circuit that controls the rising timing of a first pulse signal applied to a first control gate electrode of a multi-gate element, and a comparison circuit that obtains a comparison result of a voltage associated with the voltage between a first electrode and a second electrode of the multi-gate element and a first voltage or a second voltage smaller than the first voltage. The control circuit obtains, based on the comparison result, a transition time of the voltage associated with the voltage between the first electrode and the second electrode of the multi-gate element at the time of turning on from below the first voltage to below the second voltage, and adjusts the rising timing of the first pulse signal so as to reduce the transition time.

[0006] The driving method of a multi-gate element according to the present embodiment obtains a comparison result of a voltage associated with the voltage between a first electrode and a second electrode of a multi-gate element and a first voltage or a second voltage smaller than the first voltage, and based on the comparison result, obtains a transition time of the voltage associated with the voltage between the first electrode and the second electrode of the multi-gate element at the time of turning on from below the first voltage to below the second voltage, and adjusts the rising timing of a first pulse signal so as to reduce the transition time.

[0007] The electronic system of the embodiment includes a multi-gate element, a control circuit that controls a rising timing of a first pulse signal applied to a first control gate electrode of the multi-gate element, and a comparison circuit that acquires a comparison result of a voltage associated with a voltage between a first electrode and a second electrode of the multi-gate element and a first voltage or a second voltage smaller than the first voltage. The control circuit acquires a transition time from below the first voltage to below the second voltage of the voltage associated with the voltage between the first electrode and the second electrode of the multi-gate element at the time of conduction, based on the comparison result, and adjusts the rising timing of the first pulse signal so as to reduce the transition time. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a diagram showing a configuration of a drive system of the multi-gate element of Embodiment 1.

[0009] Figure 2 is a diagram showing an example of a pattern of each pulse signal of the TG-IGBT.

[0010] Figure 3 is a diagram showing a detailed configuration of the comparison circuit of Embodiment 1.

[0011] Figure 4 is a diagram showing a temporal change of the voltage Vn at the time of conduction.

[0012] Figure 5 is a diagram showing a relationship between the conduction loss and the transition time.

[0013] Figure 6 is a diagram showing a relationship between the conduction loss and the transition time.

[0014] Figure 7 is a diagram showing a detailed situation of the feedback control of Embodiment 1.

[0015] Figure 8 is a diagram showing a detailed situation of the feedback control of Embodiment 1.

[0016] Figure 9 is a diagram showing a configuration of a drive system of the multi-gate element of Embodiment 2.

[0017] Figure 10 is a diagram showing a configuration of a drive system of the multi-gate element of Embodiment 3.

[0018] Figure 11 is a diagram showing a detailed configuration of the comparison circuit of Embodiment 3.

[0019] Figure 12 is a diagram showing a relationship between the conduction loss and the second elapsed time.

[0020] REFERENCE SIGNS

[0021] 10 TG-IGBT (multi-gate element)

[0022] 11 gate resistor

[0023] 12 gate resistor

[0024] 13 gate resistor

[0025] 20 control circuit

[0026] 30 voltage dividing circuit

[0027] 31 resistor

[0028] 32 resistor

[0029] 40 comparison circuit

[0030] 41 first comparator

[0031] 42 second comparator

[0032] 43 resistor

[0033] 44 resistor

[0034] 45 resistor

[0035] 100 drive system of multi-gate element (electronic system)

[0036] 200 drive system of multi-gate element (electronic system)

[0037] 220 control circuit

[0038] 240 comparison circuit

[0039] 250 A / D converter

[0040] 300 drive system of multi-gate element (electronic system)

[0041] 320 control circuit

[0042] 340 comparison circuit

[0043] 343 third comparator

[0044] 360 switch

[0045] C collector electrode (first electrode)

[0046] CGp primary control gate electrode (second control gate electrode)

[0047] CGs secondary control gate electrode (first control gate electrode)

[0048] E emitter electrode (second electrode)

[0049] MG main gate electrode

[0050] N nodes

[0051] N1 node

[0052] N2 node

[0053] S1 First comparison signal

[0054] S2 Second Comparison Signal

[0055] S3 Third Comparison Signal

[0056] T transition time

[0057] Tp1 First elapsed time

[0058] Tp2 Second elapsed time

[0059] V1 positive voltage

[0060] Vcc positive power supply

[0061] Vcom common voltage

[0062] Vn Voltage after voltage division

[0063] Vee negative power source

[0064] Vth1 First Voltage

[0065] Vth2 Second Voltage

[0066] Timing of the first comparison signal changing from Low to High (t1)

[0067] The timing of the second comparison signal changing from Low to High (t2)

[0068] Falling timing of the first pulse signal of toff1

[0069] Falling timing of the second pulse signal of toff2

[0070] Rising timing of the first pulse signal of ton1

[0071] Rising timing of the second pulse signal of ton2

[0072] α learning rate

[0073] β learning rate

[0074] Δt1 is a minute quantity (a specified quantity).

[0075] Δt2 is a minute quantity (a specified quantity).

[0076] The convergence criterion for ε1 (the specified value)

[0077] The value used to determine the convergence of ε2 (the specified value). Detailed Implementation

[0078] Hereinafter, this embodiment will be described with reference to the accompanying drawings. In the drawings, the same or corresponding elements are labeled with the same reference numerals, and detailed descriptions are omitted where appropriate.

[0079] (Implementation Method 1)

[0080] Figure 1 This diagram illustrates the configuration of the driving system 100 (electronic system) for the multi-gate element in Embodiment 1. The driving system 100 includes a tri-gate IGBT 10 (TG-IGBT 10), an example of a multi-gate element, a control circuit 20, a voltage divider circuit 30, and a comparator circuit 40. The control circuit 20, the voltage divider circuit 30, and the comparator circuit 40 constitute the electronic circuitry for driving the TG-IGBT 10. Besides the tri-gate IGBT, other multi-gate elements include, for example, a dual-gate IGBT (DG-IGBT).

[0081] The TG-IGBT10 has a main gate electrode MG, a primary control gate electrode CGp (second control gate electrode), a secondary control gate electrode CGs (first control gate electrode), a collector electrode C (first electrode), and an emitter electrode E (second electrode). The main gate electrode MG is used for collector-emitter conduction control, similar to the gate electrode in a typical single-gate IGBT. The primary control gate electrode CGp and the secondary control gate electrode CGs are used to control the accumulated carrier density. Specifically, the primary control gate electrode CGp is ​​used to pre-deposit charge during turn-off. The secondary control gate electrode CGs is used to supply charge during turn-on.

[0082] The control circuit 20 is constructed, for example, by an FPGA (Field Programmable Gate Array), a CPU (Central Processing Unit), or an ASIC (Application Specified Integrated Circuit). The control circuit 20 applies a main pulse signal to the main gate electrode MG of the TG-IGBT 10 via gate resistor 11. The control circuit 20 applies a primary pulse signal (second pulse signal) to the primary control gate electrode CGp of the TG-IGBT 10 via gate resistor 12. The control circuit 20 applies a secondary pulse signal (first pulse signal) to the secondary control gate electrode CGs of the TG-IGBT 10 via gate resistor 13. The control circuit 20 controls the switching operation of the TG-IGBT 10 by controlling the rise and fall of each pulse signal.

[0083] The values ​​of gate resistors 11 to 13 can be the same or different. Alternatively, the gate resistors for a positive voltage pulse signal and for a negative voltage pulse signal can be set separately. In this case, a diode is connected in series with the gate resistor. The diode connected in series with the gate resistor used in the current path under positive voltage is mounted with the anode on the control circuit 20 side and the cathode on the gate electrode side. The diode connected in series with the gate resistor used in the current path under negative voltage is mounted with the anode on the gate electrode side and the cathode on the control circuit 20 side. Furthermore, since multi-gate elements generally have large gate capacitances, a current amplification circuit can be added to the output of the control circuit 20 to supply charge to each gate electrode of the TG-IGBT10 at high speed.

[0084] Figure 2 This diagram illustrates an example of the pattern of pulse signals applied to the gate electrodes of a TG-IGBT10. The collector-emitter conduction of the TG-IGBT10 is controlled by a main pulse signal applied to the main gate electrode MG. The high-voltage side of the main pulse signal is +15V, and the low-voltage side is -15V. When the main pulse signal rises to +15V, the collector-emitter conduction of the TG-IGBT10 is turned on. However, the value of the high-voltage side of the main pulse signal is not limited to +15V, as long as it is higher than a threshold voltage determined by the characteristics of the TG-IGBT10. Similarly, the value of the low-voltage side of the main pulse signal is not limited to -15V, as long as it is lower than this threshold voltage.

[0085] The primary pulse signal applied to the primary gate electrode CGp is ​​controlled primarily to reduce turn-off losses. The high-voltage side of the primary pulse signal is +15V, and the low-voltage side is -15V. However, the value of the high-voltage side of the primary pulse signal is not limited to +15V, as long as it exceeds the threshold voltage determined by the characteristics of the TG-IGBT10. Similarly, the value of the low-voltage side of the primary pulse signal is not limited to -15V, as long as it is below this threshold voltage.

[0086] The rise timing (ton1) and fall timing (toff1) of the primary pulse signal are defined as the relative delay times from the rise timing of the main pulse signal. For example, when ton1 is 0 or higher, the primary pulse signal rises after ton1 of the rise timing of the main pulse signal and falls after toff1 of the rise timing of the main pulse signal. On the other hand, when ton1 is less than 0, the primary pulse signal rises before ton1 of the rise timing of the main pulse signal and falls before toff1 of the rise timing of the main pulse signal. However, ton1 and toff1 can also be defined based on other timings. The fall timing (toff1) of the primary pulse signal affects the turn-off loss. The rise timing (ton1) of the primary pulse signal affects the turn-on loss.

[0087] The secondary pulse signal applied to the secondary control gate electrodes CGs is primarily controlled to reduce conduction losses. The high-voltage side of the secondary pulse signal is +15V, and the low-voltage side is 0V. However, the value of the high-voltage side of the secondary pulse signal is not limited to +15V, as long as it is higher than the threshold voltage determined by the characteristics of the TG-IGBT10. Similarly, the value of the low-voltage side of the secondary pulse signal is not limited to 0V, as long as it is lower than the threshold voltage.

[0088] The rise timing ton2 and fall timing tooff2 of the secondary pulse signal are defined as the relative delay time from the rise timing of the main pulse signal. For example, when ton2 is greater than or equal to 0, the secondary pulse signal rises after ton2 of the rise timing of the main pulse signal and falls after tooff2 of the rise timing of the main pulse signal. On the other hand, when ton2 is less than 0, the secondary pulse signal rises before ton2 of the rise timing of the main pulse signal and falls before tooff2 of the rise timing of the main pulse signal. However, ton2 and tooff2 can also be defined based on other timings. The rise timing ton2 of the secondary pulse signal affects the conduction loss. To prevent a decrease in the short-circuit withstand capability of the TG-IGBT10, the secondary pulse signal preferably only briefly reaches +15V during conduction and then immediately falls.

[0089] Control circuit 20 adjusts Figure 2 Two of the four parameters (ton1, toff1, ton2, toff2) shown, specifically the rise timing ton1 of the primary pulse signal and the rise timing ton2 of the secondary pulse signal, are used to reduce the conduction loss of the TG-IGBT10. Furthermore, the control circuit 20 reduces the turn-off loss of the TG-IGBT10 by adjusting the fall timing toff1 of the primary pulse signal, and prevents a decrease in the short-circuit withstand capability of the TG-IGBT10 by adjusting the fall timing toff2 of the secondary pulse signal. However, since this embodiment primarily aims to reduce the conduction loss of the TG-IGBT10, toff1 and toff2 are described with predetermined values ​​fixed.

[0090] return Figure 1 The voltage divider circuit 30 includes resistors 31 and 32 to divide the collector-emitter voltage Vce of the TG-IGBT10 at a predetermined ratio. The voltage division ratio is set such that the maximum value of voltage Vn converges to the voltage level that the comparator circuit 40 can input. As an example, when the resistor ratio is set to 9:1, a voltage Vn equal to 1 / 10 of the collector-emitter voltage Vce appears at node N of the voltage divider circuit 30.

[0091] Furthermore, resistor 31, which is connected to the collector side of at least one of resistors 31 and 32, such as TG-IGBT10, can also be a variable resistor, such as a digital potentiometer, consisting of a fixed resistor and a variable resistor connected in series. This makes adjusting the voltage division ratio easier. Alternatively, a capacitor can be used instead of a resistor.

[0092] The comparator circuit 40 obtains the comparison result of the voltage Vn after being divided by the voltage divider circuit 30 with either the first voltage Vth1 or the second voltage Vth2. More specifically, it compares the voltage Vn with either the first voltage Vth1 or the second voltage Vth2 respectively and outputs the comparison result. The first voltage Vth1 can also be set as the voltage associated with the start of conduction or a first threshold voltage. The second voltage Vth2 can also be set as the voltage associated with the completion of conduction or a second threshold voltage. Figure 3 This is a diagram showing the detailed configuration of the comparator circuit 40. The comparator circuit 40 includes a first comparator 41, a second comparator 42, and three resistors 43-45 connected in series between the positive voltage V1 and the common voltage Vcom. The positive voltage V1 is, for example, +5V used in general electronic devices.

[0093] By appropriately setting the values ​​of resistors 43 to 45, the voltage at node N1 is set to the first voltage Vth1, and the voltage at node N2 is set to the second voltage Vth2. The negative input voltage Vn of the first comparator 41 is input to the first voltage Vth1, and the positive input voltage Vth1 is input to the second comparator 42. The negative input voltage Vn of the second comparator 42 is input to the second voltage Vth2, and the positive input voltage Vth2 is input to the second comparator.

[0094] The first comparator 41 outputs a Low signal when the voltage Vn exceeds the first voltage Vth1, and outputs a High signal when the voltage Vn is below the first voltage Vth1. The output of the first comparator 41 becomes the first comparison signal S1 and is input to the control circuit 20. The second comparator 42 outputs a Low signal when the voltage Vn exceeds the second voltage Vth2, and outputs a High signal when the voltage Vn is below the second voltage Vth2. The output of the second comparator 42 becomes the second comparison signal S2 and is input to the control circuit 20.

[0095] The first voltage Vth1 and the second voltage Vth2 are set such that the transition time T from when voltage Vn falls below Vth1 to when it falls below Vth2 is approximately equal to the on-time of the TG-IGBT10. More specifically, as follows... Figure 4 As shown, the first voltage Vth1 is set to a value slightly lower than the voltage Vn when the TG-IGBT10 is not conducting. This is to accurately obtain the timing that can be considered as the start of conduction while avoiding the influence of voltage Vn fluctuations immediately after conduction begins. As an example, the first voltage Vth1 is set to 0.91 times the maximum value of voltage Vn.

[0096] The second voltage Vth2 is set to a value slightly higher than the voltage Vn when the TG-IGBT10 is turned on. This is to accurately obtain the timing that can be considered as the completion of conduction while avoiding the influence of voltage Vn fluctuations just before the completion of conduction. As an example, the second voltage Vth2 is set to 0.16 times the maximum value of voltage Vn.

[0097] By setting the first voltage Vth1 and the second voltage Vth2 as described above, the transition time T from when the voltage Vn is lower than the first voltage Vth1 and the first comparison signal S1 changes from Low to High until the voltage Vn is lower than the second voltage Vth2 and the second comparison signal S2 changes from Low to High is approximately equal to the turn-on time of TG-IGBT10.

[0098] The control circuit 20 measures the transition time T, for example, using its own built-in counter. Specifically, the control circuit 20 times the change in the first comparison signal S1 output from the comparison circuit 40 from Low to High. Figure 4 The built-in counter is turned on by t1, and the timing is when the second comparison signal S2 output from the comparison circuit 40 changes from Low to High. Figure 4 t2) disconnects the built-in counter. Furthermore, in cases where the transition time T is short and a sampling frequency exceeding the operating frequency of the control circuit 20 is required, a component capable of achieving higher time resolution, such as a TDC (Time to Digital Converter), can be used instead of the built-in counter.

[0099] Here, the relationship between the conduction loss and the transition time T of TG-IGBT10 is explained. Figure 5 The curve on the left shows the relationship between ton1 and conduction loss when ton1 is manually varied. Figure 5 The graph on the right shows the relationship between ton1 and transition time T when ton1 is manually varied. Comparing the two graphs reveals a correlation. Therefore, by adjusting ton1 in a manner that minimizes transition time T, control circuit 20 can minimize the conduction loss of TG-IGBT10. Figure 5 In the example, control circuit 20 only needs to make ton1 equal to zero.

[0100] Figure 6 The curve on the left shows the relationship between ton2 and conduction loss when ton2 is manually varied. Figure 6The graph on the right shows the relationship between ton2 and transition time T when ton2 is manually varied. Comparing the two graphs, a correlation is found between them. Therefore, by adjusting ton2 in a way that minimizes the transition time T, the control circuit 20 can minimize the conduction loss of the TG-IGBT10. Figure 6 In the example, the control circuit 20 only needs to make ton2 equal to ton2_* in the figure.

[0101] As described above, by utilizing the correlation between the conduction loss and transition time T of the TG-IGBT10, ton1 and ton2 can be adjusted to minimize the transition time T, thereby minimizing the conduction loss. However, the characteristics of the TG-IGBT10 vary due to environmental changes and component degradation over time. Environmental changes include variations in external temperature, heat generation of the TG-IGBT10, and changes in the characteristics of surrounding circuits and loads. Furthermore, there are cases where the characteristics of each component of the TG-IGBT10 differ significantly. If the characteristics of the TG-IGBT10 change, then ton1 and ton2, which minimize the conduction loss, also change.

[0102] In this embodiment 1, even if ton1 and ton2, which minimize conduction losses, change due to environmental variations or component degradation over time, feedback control adaptively adjusts ton1 and ton2 accordingly. Here, feedback control refers to adjusting the subsequent processing of ton1 and ton2 based on the transition time T obtained using the current ton1 and ton2, in a manner that minimizes conduction losses. Specifically, the transition time T is considered as a function of ton1 and ton2, and the gradient descent method is used to search for ton1 and ton2 that minimize the transition time T.

[0103] Here, the feedback control of Embodiment 1 will be described in detail. As an example, consider a case where the drive system 100 of the TG-IGBT 10 is assembled into a power conversion device, which is the final product. The TG-IGBT 10 assembled into the power conversion device repeatedly performs switching operations according to the pulse signals applied from the control circuit 20.

[0104] The control circuit 20 continuously monitors the transition time T, which is related to the conduction loss of the TG-IGBT10. If the transition time T exceeds a specified reference value, a deterioration in the conduction loss is detected, and then... Figure 7 The flowchart illustrates the feedback control.

[0105] In step S101, the control circuit 20 sets ton1 and ton2 to initial values ​​ton1(1) and ton2(1), respectively. Additionally, the number of trials n is set to an initial value of 1. During the initial execution of feedback control, for example, ton1 and ton2 are changed at predetermined step intervals, and the one with the smallest conduction loss is selected and set as the initial values ​​ton1(1) and ton2(1). In subsequent executions of feedback control, the current ton1 and ton2 are directly set to the initial values ​​ton1(1) and ton2(1).

[0106] In step S102, the control circuit 20, utilizing the switching action of the TG-IGBT10 which continues even during the execution of feedback control, turns on the TG-IGBT10 using ton1(n) and ton2(n) during the nth trial (see reference). Figure 8 In detail, the control circuit 20 first causes the main pulse signal to rise, then causes the primary pulse signal to rise after ton1(n) from the rise timing of the main pulse signal, and then causes the secondary pulse signal to rise after ton2(n) from the rise timing of the main pulse signal.

[0107] In step S103, the control circuit 20 obtains the first transition time T1(n) for the nth trial. Specifically, when the TG-IGBT 10 is turned on, the control circuit 20 obtains the first transition time T1(n) as the time from when the first comparison signal S1 of the comparison circuit 40 changes from Low to High until the second comparison signal S2 of the comparison circuit 40 changes from Low to High. Afterwards, as the switching action of the TG-IGBT 10 continues during the execution of feedback control, the primary pulse signal and the secondary pulse signal decrease at predetermined timings tooff1 and tooff2.

[0108] In step S104, the control circuit 20, by reusing the switching action of the TG-IGBT10 which continues during the execution of feedback control, uses ton1(n)+Δt1 and ton2(n)+Δt2, which change ton1(n) and ton2(n) by a small amount (a specified amount) during the nth trial, to turn on the TG-IGBT10 (refer to...). Figure 8In detail, the control circuit 20 first causes the main pulse signal to rise, then causes the primary pulse signal to rise after ton1(n) + Δt1 from the rise timing of the main pulse signal, and then causes the secondary pulse signal to rise after ton2(n) + Δt2 from the rise timing of the main pulse signal. Furthermore, the minute quantities Δt1 and Δt2 can be the same value or different values. For example, Δt1 and Δt2 are set to a time corresponding to the operating speed of the circuit (e.g., FPGA), such as the time per sample of the operating speed. If the operating speed is 100 MHz, then Δt1 and Δt2 are set to 10 nanoseconds. However, the method of setting Δt1 and Δt2 is not limited to this method; they can be set to the time of two or more samples, or Δt1 and Δt2 can be set from a viewpoint different from the operating speed.

[0109] In step S105, the control circuit 20 obtains the second transition time T2(n) for the nth trial. Specifically, when the TG-IGBT 10 is turned on, the control circuit 20 obtains the second transition time T2(n) as the time from when the first comparison signal S1 of the comparison circuit 40 changes from Low to High until the second comparison signal S2 of the comparison circuit 40 changes from Low to High. Afterwards, as the switching action of the TG-IGBT 10 continues during the execution of feedback control, the primary pulse signal and the secondary pulse signal decrease at predetermined timings tooff1 and tooff2.

[0110] In step S106, the control circuit 20 updates ton1(n) and ton2(n) based on the first transition time T1(n) and the second transition time T2(n) during the nth trial. Specifically, the control circuit 20 calculates ton1(n+1) and ton1(n+1) according to the following formula based on the first transition time T1(n) and the second transition time T2(n).

[0111] ton1(n+1)=ton1(n)-α(T2(n)-T1(n)) / Δt1

[0112] ton2(n+1)=ton2(n)-β(T2(n)-T1(n)) / Δt2

[0113] In the above formula, α and β are the learning rates, which can be the same or different values. Alternatively, the learning rates α and β can be varied during each trial.

[0114] In step 107, the control circuit 20 determines the end condition of the search. For example, the control circuit 20 determines whether both of the following two conditional expressions are true.

[0115] |ton1(n+1)-ton1(n)|<ε1

[0116] |ton2(n+1)-ton2(n)|<ε2

[0117] In the above formula, ε1 and ε2 are values ​​(specified values) used for convergence determination. They can be the same value or different values.

[0118] If the termination condition in step S107 is met (S107 = Yes), the control circuit 20 ends the search (RET). Otherwise (S107 = No), the control circuit 20 increments the trial count n by 1 (S108) and returns to step S102.

[0119] At the end of the search, ton1(n) and ton2(n) are adjusted to minimize, for example, the characteristics of the current TG-IGBT10 to reduce conduction losses. By using the adjusted ton1 and ton2 to control the switching action of the TG-IGBT10, the control circuit 20 can reduce conduction losses, for example, minimize them.

[0120] As described above, when the conduction loss of TG-IGBT10 deteriorates, by performing... Figure 7 The feedback control can adaptively adjust ton1 and ton2, which minimize conduction losses, even when these values ​​change due to environmental variations or component degradation over time. Furthermore, feedback control can be implemented at regular time intervals, not limited to cases of deteriorating conduction losses. However, due to the nature of gradient descent, ton1 and ton2 at the end of the search may not correspond to the global minimum of conduction losses, but rather to a local minimum. Even in this case, conduction losses can still be reduced.

[0121] As explained above, in the multi-gate element drive system 100 of Embodiment 1, the control circuit 20, based on the comparison result of the comparator circuit 40, obtains the transition time T from when the voltage Vn associated with the collector-emitter voltage Vce when the TG-IGBT 10 is turned on, is lower than the first voltage Vth1, until it is lower than the second voltage Vth2. The control circuit 20 adjusts the rise timing ton1 of the primary pulse signal and the rise timing ton2 of the secondary pulse signal to reduce the transition time T, preferably to minimize it. Based on this feature, the drive system 100 of Embodiment 1 can reduce conduction losses, preferably to minimize them, even when the characteristics of the TG-IGBT 10 change due to environmental variations or the deterioration of components over time.

[0122] Furthermore, in this embodiment 1, instead of estimating the conduction loss based on the product of the collector-emitter voltage and the collector current of the TG-IGBT 10, the correlation between conduction loss and transition time T is utilized to reduce conduction loss based on the transition time T. Typically, measuring the collector current of a TG-IGBT requires a current sensing resistor, a wideband current sensor, etc. Current sensing resistors incur losses, and wideband current sensors are expensive. In contrast, in this embodiment 1, the voltage divider circuit 30 and the comparator circuit 40 used to obtain the transition time T obtain the transition time T based on the voltage Vn obtained by dividing the collector-emitter voltage Vce, and are composed of only a few resistors and comparators. Therefore, the voltage divider circuit 30 and the comparator circuit 40 of this embodiment 1 are low-loss, small-sized, and low-cost. Such features are particularly advantageous when assembling a drive system 100 in a final product equipped with a TG-IGBT 10.

[0123] Furthermore, when performing the feedback control of this embodiment 1 for the first time, in Figure 7 In step S101, ton1 and ton2 are changed in advance at a predetermined step interval, and the one with the minimum conduction loss is selected and set as the initial value ton1(1) and ton2(1). Thus, the gradient descent search can start from the vicinity of the global minimum. As a result, there is a high probability that ton1 and ton2 at the end of the search correspond to the global minimum of conduction loss.

[0124] Furthermore, with the aim of reducing conduction losses, and under ideal conditions where the characteristics of components and circuits are without deviation, the voltage of the secondary pulse signal preferably begins to rise from the moment the voltage of the main pulse signal reaches 0V. In fact, referring to... Figure 4 and Figure 5 The conduction loss of ton1 is approximately zero, while the conduction loss of ton2, i.e., ton2_*, is a value greater than zero.

[0125] Therefore, when selecting ton1 and ton2 with the minimum conduction loss, it is preferable to select ton2 first and then ton1. Specifically, first, ton1 is fixed to zero, and ton2 is changed at a specified step interval. The one with the minimum conduction loss is selected as the initial value ton2(1). Then, ton2 is fixed to the initial value ton2(1), and ton1 is changed at a specified step interval. The one with the minimum conduction loss is selected as the initial value ton1(1).

[0126] Furthermore, in the feedback control of this embodiment 1, ton1 and ton2 are adjusted simultaneously, but they can also be adjusted independently. For example, ton2, which has a greater impact on conduction loss, can be adjusted first, followed by ton1. In this case, ton1 can be kept fixed at zero during the adjustment of ton2. Alternatively, ton1, which has a smaller impact on conduction loss, can be kept fixed at zero, and only ton2, which has a greater impact on conduction loss, can be adjusted.

[0127] (Implementation Method 2)

[0128] Figure 9 This diagram illustrates the configuration of the driving system 200 for the multi-gate element in Embodiment 2. The driving system 200 includes an A / D converter 250 that converts the voltage Vn, after being divided by the voltage divider circuit 30, into a digital signal. A comparator circuit 240 compares the voltage Vn, converted into a digital signal by the A / D converter 250, with either a quantized first voltage Vth1 (the first voltage Vth1 of the digital signal) or a quantized second voltage Vth2 (the second voltage Vth2 of the digital signal), and outputs the comparison result as a digital signal.

[0129] In Embodiment 1 described above, the comparator circuit 40 is configured as an analog circuit. In contrast, in Embodiment 2, the comparator circuit 240 is configured as a digital circuit. As a result, all signals within the area enclosed by the dashed lines in the figure become digital signals. Thus, for example, the control circuit 220 and the comparator circuit 240 can be configured using the same FPGA, CPU, or ASIC.

[0130] (Implementation Method 3)

[0131] Figure 10 This diagram illustrates the configuration of the driving system 300 for the multi-gate element in Embodiment 3. The driving system 300 includes a switch 360 that selectively outputs either a first voltage Vth1 or a second voltage Vth2 according to a switching signal input from the control circuit 320. The switch 360 can selectively generate and output either the first voltage Vth1 or the second voltage Vth2 internally, or it can selectively output the first voltage Vth1 or the second voltage Vth2 input from an external source.

[0132] The comparator circuit 340 compares the voltage Vn divided by the voltage divider circuit 30 with either the first voltage Vth1 or the second voltage Vth2 output from the switch 360, and outputs the comparison result. Figure 11This is a diagram showing the detailed configuration of the comparator circuit 340. The comparator circuit 340 includes a third comparator 343. A voltage Vn is input to the negative input of the third comparator 343, and either a first voltage Vth1 or a second voltage Vth2 is input to the positive input. The output of the third comparator 343 becomes the third comparison signal S3, which is input to the control circuit 320.

[0133] When the transition time T is obtained, the control circuit 320 first outputs a first voltage Vth1 from the switch 360 to obtain a first elapsed time Tp1 from a predetermined reference time until the output of the comparator circuit 340 changes. For example, the reference time is set to the rise time of the main pulse signal. Next, the control circuit 320 causes a second voltage Vth2 to be output from the switch 360 to obtain a second elapsed time Tp2 from the aforementioned reference time until the output of the comparator circuit 340 changes. The control circuit 340 calculates the transition time T based on the difference between the second elapsed time Tp2 and the first elapsed time Tp1.

[0134] In Embodiment 1 described above, the comparator circuit 40 consists of two comparators 41 and 42 and three resistors 43 to 35. In contrast, in Embodiment 3, the comparator circuit 340 consists of only one comparator 343. Due to this feature, the comparator circuit 340 of Embodiment 3 has fewer components, is smaller, and has lower cost compared to the comparator circuit 40 of Embodiment 1.

[0135] Furthermore, in this embodiment 3, when the reference time is set to the rise time of the main gate signal, Tp1 << Tp2 holds true. Additionally, ton2 has a greater impact on conduction losses than ton1. Therefore, by adjusting ton1, which has a smaller impact on conduction losses, it is possible to approximate the transition time T ≒ the second elapsed time Tp2.

[0136] In fact, such as Figure 12 As shown, the relationship between ton1 and the second elapsed time Tp2 when ton1 is manually changed ( Figure 12 The curve on the left) and the relationship between ton1 and conduction loss when ton1 is manually changed ( Figure 12 The curve on the right is extremely similar.

[0137] Therefore, when adjusting ton1 via feedback control, the control circuit 320 can also approximate the transition time T by using a second elapsed time Tp2, thereby reducing the second elapsed time Tp2. Thus, when adjusting ton1, there is no need to obtain the process of Tp1, thereby shortening the time required for adjusting ton1 and making the feedback control faster.

[0138] However, when adjusting ton2, which has a significant impact on conduction loss, the contribution of the first elapsed time Tp1 cannot be ignored, and adjustments need to be made based on the transition time T = Tp2 - Tp1.

[0139] Several embodiments have been described, but these embodiments are provided as examples and are not intended to limit the scope of the embodiments. These embodiments can be implemented in various other ways, and various omissions, substitutions, changes, combinations, etc., can be made without departing from the spirit of the embodiments. These embodiments and their variations are included in the scope or spirit of the embodiments, and are also included in the scope of the claims and their equivalents.

[0140] Furthermore, this embodiment can also be configured as follows.

[0141] [1] (Examples 1, 2, and 3)

[0142] An electronic circuit, comprising:

[0143] Control circuitry controls the rise timing of a first pulse signal applied to the first control gate electrode of a multi-gate element; and

[0144] The comparator circuit obtains a comparison result between a voltage associated with the voltage between the first and second electrodes of the multi-gate element and a first voltage or a second voltage that is smaller than the first voltage.

[0145] Based on the comparison result, the control circuit obtains the transition time from when the voltage associated with the first electrode and the second electrode when the multi-gate element is turned on to when the voltage is lower than the first voltage and then to when the voltage is lower than the second voltage, and adjusts the rise timing of the first pulse signal to reduce the transition time.

[0146] [2] (Examples 1, 2, and 3)

[0147] According to the electronic circuit described in technical solution 1

[0148] The control circuit also controls the rise timing of the second pulse signal applied to the second control gate electrode of the multi-gate element, and adjusts the rise timing of the second pulse signal to reduce the transition time.

[0149] 【3】(Examples 1, 2, 3)

[0150] The electronic circuit according to technical solution 1 or 2

[0151] The control circuit adjusts the rise timing of the first pulse signal and the second pulse signal to minimize the transition time.

[0152] [4] (Examples 1, 2, and 3)

[0153] The electronic circuit according to technical solution 2 or 3

[0154] The rise timing of the first pulse signal and the second pulse signal is a relative delay time relative to the rise timing of the main pulse signal applied to the main gate electrode of the multi-gate element.

[0155] 【5】(Examples 1, 2, 3)

[0156] According to the electronic circuit described in technical solution 1

[0157] It also includes a voltage divider circuit that divides the voltage between the first electrode and the second electrode.

[0158] The comparator circuit is input with the voltage divided by the voltage divider circuit.

[0159] [6] (Examples 1, 2, and 3)

[0160] According to the electronic circuit described in technical solution 5

[0161] The voltage divider circuit includes two resistors, at least one of which is a variable resistor.

[0162] 【7】(Example 1)

[0163] The electronic circuit according to technical solution 5 or 6

[0164] The comparison circuit includes:

[0165] The first comparator compares the divided voltage with the first voltage and outputs the comparison result; and

[0166] The second comparator compares the divided voltage with the second voltage and outputs the comparison result.

[0167] The control circuit obtains the transition time based on the outputs of the first comparator and the second comparator.

[0168] 【8】(Example 1)

[0169] According to the electronic circuit described in technical solution 7

[0170] The control circuit obtains the transition time based on the time from when the output of the first comparator changes until when the output of the second comparator changes.

[0171] 【9】(Example 2)

[0172] According to the electronic circuit described in technical solution 5

[0173] It also includes an A / D converter that converts the voltage after voltage division into a digital signal.

[0174] The comparison circuit compares the magnitude of the digital signal of the voltage after voltage division with the magnitude of the first voltage of the digital signal or the second voltage of the digital signal, and obtains the comparison result as the digital signal.

[0175]

[10] (Examples 1, 2, and 3)

[0176] The electronic circuit according to any one of technical solutions 2 to 9,

[0177] When the rise timing of the first pulse signal and the second pulse signal is changed by a predetermined amount, the rise timing of the first pulse signal and the second pulse signal is adjusted in the direction of reducing the transition time.

[0178]

[11] (Examples 1, 2, and 3)

[0179] According to the electronic circuit described in technical solution 10

[0180] If the change in transition time when the rise timing of the first pulse signal and the second pulse signal changes by the predetermined amount becomes less than or equal to a predetermined value, then the adjustment of the rise timing of the first pulse signal and the second pulse signal ends.

[0181]

[12] (Examples 1, 2, and 3)

[0182] The electronic circuit according to any one of technical solutions 2 to 11,

[0183] The rise timing of the first pulse signal and the second pulse signal are adjusted independently.

[0184]

[13] (Examples 1, 2, and 3)

[0185] The electronic circuit according to any one of technical solutions 2 to 12,

[0186] The initial value of the rise timing of the first pulse signal and the second pulse signal is set to a timing that minimizes the transition time when the rise timing of the first pulse signal and the second pulse signal changes at a predetermined step interval.

[0187]

[14] (Examples 1, 2, and 3)

[0188] The electronic circuit according to technical solution 13

[0189] After setting the initial value of the rise timing of the second pulse signal, the initial value of the rise timing of the first pulse signal is set.

[0190]

[15] (Example 3)

[0191] According to the electronic circuit described in technical solution 5

[0192] The comparison circuit includes:

[0193] The switch, according to a switching signal input from the control circuit, selectively outputs either the first voltage or the second voltage; and

[0194] The third comparator compares the voltage after voltage division with either the first voltage or the second voltage output from the switch, and outputs the comparison result.

[0195] The control circuit causes the first voltage to be output from the switch to obtain a first elapsed time from a predetermined reference time to the change of the output of the third comparator, and then causes the second voltage to be output from the switch to obtain a second elapsed time from the reference time to the change of the output of the third comparator. The transition time is obtained based on the difference between the first elapsed time and the second elapsed time.

[0196]

[16] (Example 3)

[0197] The electronic circuit according to technical solution 15

[0198] The reference time is the rise time of the main pulse signal applied to the main gate electrode of the multi-gate element.

[0199]

[17] (Example 3)

[0200] The electronic circuit described in technical solution 15 or 16

[0201] The control circuit also controls the rise timing of the second pulse signal applied to the second control gate electrode of the multi-gate element, and adjusts the rise timing of the second pulse signal to reduce the second elapsed time.

[18]

[0203] A method for driving a multi-gate element includes the following steps:

[0204] The voltage associated with the voltage between the first and second electrodes of the multi-gate element is compared with a first voltage or a second voltage that is smaller than the first voltage.

[0205] Based on the comparison results, the transition time from when the voltage between the first electrode and the second electrode is turned on with the multi-gate element being lower than the first voltage to when it is lower than the second voltage is obtained.

[0206] Adjust the rise timing of the first pulse signal to reduce the transition time.

[19]

[0208] An electronic system comprising:

[0209] Multi-gate devices;

[0210] Control circuitry controls the rise timing of a first pulse signal applied to the first control gate electrode of the multi-gate element; and

[0211] The comparator circuit obtains a comparison result between the voltage associated with the voltage between the first and second electrodes of the multi-gate element and either a first voltage or a second voltage.

[0212] Based on the comparison result, the control circuit obtains the transition time from when the voltage associated with the first electrode and the second electrode when the multi-gate element is turned on to when the voltage is lower than the first voltage and then to when the voltage is lower than the second voltage, and adjusts the rise timing of the first pulse signal to reduce the transition time.

Claims

1. An electronic circuit, characterized in that, have: The control circuit controls the rise timing of the first pulse signal applied to the first control gate electrode of the multi-gate element; as well as The comparator circuit obtains a comparison result between a voltage associated with the voltage between the first and second electrodes of the multi-gate element and a first voltage or a second voltage that is smaller than the first voltage. Based on the comparison result, the control circuit obtains the transition time from when the voltage associated with the first electrode and the second electrode when the multi-gate element is turned on to when the voltage is lower than the first voltage to when it is lower than the second voltage, and adjusts the rise timing of the first pulse signal to reduce the transition time.

2. The electronic circuit according to claim 1, characterized in that, The control circuit also controls the rise timing of the second pulse signal applied to the second control gate electrode of the multi-gate element, and adjusts the rise timing of the second pulse signal to reduce the transition time.

3. The electronic circuit according to claim 2, characterized in that, The control circuit adjusts the rise timing of the first pulse signal and the second pulse signal to minimize the transition time.

4. The electronic circuit according to claim 2, characterized in that, The rise timing of the first pulse signal and the second pulse signal is a relative delay time relative to the rise timing of the main pulse signal applied to the main gate electrode of the multi-gate element.

5. The electronic circuit according to claim 1, characterized in that, It also includes a voltage divider circuit that divides the voltage between the first electrode and the second electrode. The comparator circuit is input with the voltage divided by the voltage divider circuit.

6. The electronic circuit according to claim 5, characterized in that, The voltage divider circuit includes two resistors, at least one of which is a variable resistor.

7. The electronic circuit according to claim 5, characterized in that, The comparison circuit includes: The first comparator compares the divided voltage with the first voltage and outputs the comparison result; and The second comparator compares the divided voltage with the second voltage and outputs the comparison result. The control circuit obtains the transition time based on the outputs of the first comparator and the second comparator.

8. The electronic circuit according to claim 7, characterized in that, The control circuit obtains the transition time based on the time from when the output of the first comparator changes until when the output of the second comparator changes.

9. The electronic circuit according to claim 5, characterized in that, It also includes an A / D converter that converts the voltage after voltage division into a digital signal. The comparison circuit compares the digital signal of the voltage after voltage division with the first voltage of the digital signal or the second voltage of the digital signal, and obtains the comparison result as the digital signal.

10. The electronic circuit according to claim 2, characterized in that, When the rise timing of the first pulse signal and the second pulse signal is changed by a predetermined amount, the rise timing of the first pulse signal and the second pulse signal is adjusted in the direction of reducing the transition time.

11. The electronic circuit according to claim 10, characterized in that, If the change in transition time when the rise timing of the first pulse signal and the second pulse signal changes by the predetermined amount becomes less than or equal to a predetermined value, then the adjustment of the rise timing of the first pulse signal and the second pulse signal ends.

12. The electronic circuit according to claim 2, characterized in that, The rise timing of the first pulse signal and the second pulse signal are adjusted independently.

13. The electronic circuit according to claim 2, characterized in that, The initial value of the rise timing of the first pulse signal and the second pulse signal is set such that the transition time is minimized when the rise timing of the first pulse signal and the second pulse signal changes at a predetermined step interval.

14. The electronic circuit according to claim 13, characterized in that, After setting the initial value of the rise timing of the second pulse signal, the initial value of the rise timing of the first pulse signal is set.

15. The electronic circuit according to claim 5, characterized in that, The comparison circuit includes: The switch, according to a switching signal input from the control circuit, selectively outputs either the first voltage or the second voltage; and The third comparator compares the voltage after voltage division with either the first voltage or the second voltage output from the switch, and outputs the comparison result. The control circuit causes the first voltage to be output from the switch to obtain a first elapsed time from a predetermined reference time to the change of the output of the third comparator, and then causes the second voltage to be output from the switch to obtain a second elapsed time from the reference time to the change of the output of the third comparator. The transition time is obtained based on the difference between the first elapsed time and the second elapsed time.

16. The electronic circuit according to claim 15, characterized in that, The reference time is the rise time of the main pulse signal applied to the main gate electrode of the multi-gate element.

17. The electronic circuit according to claim 15, characterized in that, The control circuit also controls the rise timing of the second pulse signal applied to the second control gate electrode of the multi-gate element, and adjusts the rise timing of the second pulse signal to reduce the second elapsed time.

18. A driving method for a multi-gate element, characterized in that, Includes the following steps: The voltage associated with the voltage between the first and second electrodes of the multi-gate element is compared with a first voltage or a second voltage that is smaller than the first voltage. Based on the comparison results, the transition time from when the voltage between the first electrode and the second electrode when the multi-gate element is turned on, which is lower than the first voltage, to when it is lower than the second voltage, is obtained. Adjust the rise timing of the first pulse signal to reduce the transition time.

19. An electronic system, characterized in that, have: Multi-gate devices; The control circuit controls the rise timing of the first pulse signal applied to the first control gate electrode of the multi-gate element; as well as The comparator circuit obtains a comparison result between the voltage associated with the voltage between the first and second electrodes of the multi-gate element and either a first voltage or a second voltage. Based on the comparison result, the control circuit obtains the transition time from when the voltage associated with the first electrode and the second electrode when the multi-gate element is turned on to when the voltage is lower than the first voltage to when it is lower than the second voltage, and adjusts the rise timing of the first pulse signal to reduce the transition time.

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