CN211930609U - SiC MOSFET short-circuit protection circuit based on short-circuit current suppression - Google Patents
SiC MOSFET short-circuit protection circuit based on short-circuit current suppression Download PDFInfo
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- CN211930609U CN211930609U CN201921850461.2U CN201921850461U CN211930609U CN 211930609 U CN211930609 U CN 211930609U CN 201921850461 U CN201921850461 U CN 201921850461U CN 211930609 U CN211930609 U CN 211930609U
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- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 58
- 229910010271 silicon carbide Inorganic materials 0.000 description 57
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
- H03K17/081—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
- H03K17/0812—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the control circuit
- H03K17/08122—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the control circuit in field-effect transistor switches
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/687—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors
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- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The invention provides a short-circuit protection circuit of a SiC MOSFET based on short-circuit current suppression, which comprises: logic unit, drive unit, short-circuit protection unit, VDSDetection unit and VGThe invention adopts the reduction of the grid voltage VGThe method inhibits the short-circuit current, thereby reducing the impact of the short-circuit fault on the device, reducing the short-circuit loss and increasing the short-circuit tolerance time. When the SiC MOSFET is short-circuited, the drain voltage VDSWill not drop to the conduction voltage drop, the invention judges the drain voltage VDSWhether or not toReducing to conduction voltage drop to select gate drive voltage with turn-on transient state to make gate voltage VGClamping at a lower drive voltage level; when the SiC MOSFET has class II short circuit, the gate voltage VGWill generate sudden change to form voltage peak, the invention judges the grid voltage V in the conducting stateGThe gate voltage V can be adjusted during short circuit by selecting the gate drive voltage in the on state according to whether voltage spike occursGClamped at a lower drive voltage level.
Description
Technical Field
The invention relates to a SiC MOSFET short-circuit protection circuit based on short-circuit current suppression, and belongs to the technical field of power electronics.
Background
Silicon carbide (SiC) is receiving increasing attention from the power electronics industry as a new type of wide bandgap semiconductor material due to its excellent physical and electrical properties. As a third generation power semiconductor device, a SiC power device will become the dominant device of a future power converter. The SiC MOSFET is considered to be the most likely to replace the Si IGBT widely used at present due to its performance advantages of low on-resistance, high switching rate, etc., however, in practical engineering applications, the short-circuit current of the SiC MOSFET will reach as much as ten times of the rated current due to its excessively high gate voltage, so that the short-circuit loss and junction temperature rise are severe, and the short-circuit withstand time of the SiC MOSFET is greatly shortened compared with the Si IGBT of the same specification. This increases the design requirements for the SiC MOSFET short-circuit protection circuit. The most common short-circuit protection circuit at present is a drain voltage-based detection method, and the circuit of the method is the simplest, but when one type of short circuit occurs, a longer blanking time is usually set to avoid false alarm failure, so that the short-circuit failure duration is prolonged, and when the two types of short circuits occur, the detection time is also increased by a filter capacitor in a short-circuit detection circuit, so that when the circuit is adopted, the short-circuit loss is higher, the impact of a short-circuit power device is increased, in addition, an overvoltage spike of a drain electrode is increased by overhigh short-circuit current during turn-off, and the risk of drain electrode breakdown is increased.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provides a SiC MOSFET short-circuit protection circuit based on short-circuit current suppression. On the basis of traditional short-circuit fault protection, the system can reduce short-circuit current on the premise of not influencing normal switching-on performance, thereby reducing the impact of short-circuit fault on devices, and the technical scheme is as follows:
a short circuit current suppression based SiC MOSFET short circuit protection circuit, comprising: power supply and signal isolation unit, logic unit, drive unit, short-circuit protection unit, VDSDetection unit and VGA detection unit, wherein:
the power supply and signal isolation unit is used for isolating a power supply and a signal of the drive from an external controller;
the driving unit is used for providing on-off driving voltage for the grid electrode of the SiC MOSFET to be tested and reducing the driving voltage when short circuit occurs;
the short-circuit protection unit is used for detecting short-circuit faults and outputting fault signals;
the V isDSA detection unit for detecting the drain voltage V of the SiC MOSFET to be detectedDSJudging whether the drain voltage enters a conduction voltage drop state or not, and outputting a drain state signal;
the V isGA detection unit for detecting the gate voltage V of the SiC MOSFET to be detectedGJudging whether a grid overvoltage peak occurs or not, and outputting a grid state signal;
the logic unit is used for logically combining the fault signal, the drain state signal, the grid state signal and the switch signal and outputting a logic control signal;
as an improvement of the invention, the logic unit can adopt a digital chip CPLD to realize logic control, the logic program is convenient to change, but a level conversion circuit needs to be added, and an AND/NOT gate can also be adopted to build an analog circuit to realize logic control, the analog circuit does not need level conversion, the logic delay is short, but the logic form cannot be changed.
As an improvement of the invention, the driving unit comprises two positive driving voltages and a negative driving voltage, wherein the larger positive driving voltage and the negative driving voltage are used for providing the gate voltage of the SiC MOSFET to be tested in normal on and off states, and the other smaller positive driving voltage is used for limiting the gate voltage when one type of short circuit and two types of short circuits occur.
As an improvement of the invention, in order to ensure the normal turn-on rate of the SiC MOSFET to be tested, the grid resistance of the smaller positive driving voltage circuit is smaller than that of the larger positive driving voltage circuit by the driving unit.
As a modification of the present invention, said VDSThe detection unit adopts a fast high-voltage diode circuit to isolate the detection circuit from the high voltage of the drain electrode, and the drain electrode voltage detection unit and the short-circuit protection unit can share the diode circuit so as to reduce the number of devices.
As an improvement of the invention, said VGThe detection circuit adopts a hysteresis comparator, and the comparator can keep the working state of short-circuit current suppression of the driving plate in the short-circuit process of the device to be tested until the device to be tested is driven to be turned off.
As an improvement of the present invention, the short-circuit current suppression method comprises: the short-circuit fault occurs in the opening transient state of the SiC MOSFET, VDSThe detection unit detects the state of drain voltage in real time, when short circuit occurs, the drain voltage is always kept in a high voltage state, the drive unit provides smaller positive drive voltage for the grid electrode all the time in a switching transient state, and according to the output characteristic of the power device, the short circuit current corresponding to the smaller grid voltage is reduced, so that the short circuit current is restrained until the short circuit protection unit detects a short circuit fault, and the SiC MOSFET is driven to be switched off.
As an improvement of the present invention, the second type of short-circuit current suppression method is: IIShort-circuit like fault occurs in the on state of SiC MOSFET, VGThe detection unit detects the state of the grid voltage in real time, when the second type of short circuit occurs, the grid voltage is subjected to sudden change to form a higher voltage peak, when the grid voltage exceeds a certain threshold value, the driving unit is switched from a larger positive driving voltage to a smaller positive driving voltage to reduce the grid voltage, so that the short-circuit current is restrained, and the SiC MOSFET is driven to be switched off until the short-circuit protection unit detects the short-circuit fault.
Compared with the prior art, the invention has the following advantages: the circuit of the invention adds fewer devices in the traditional drive, and can reduce the grid voltage to be less than the grid voltage in normal conduction, thereby inhibiting the short-circuit current of one class and the short-circuit current of the second class, reducing the impact of junction temperature fluctuation caused by overhigh short-circuit loss on the devices, and improving the short-circuit tolerance time of the SiC MOSFET; the reduction of the short-circuit current also greatly reduces the turn-off loss and can reduce the overvoltage spike of turn-off; in the normal operation process, the normal turn-on rate of the SiC MOSFET can be ensured by setting the grid resistance parameter.
Drawings
The invention will be further explained with reference to the drawings, in which:
FIG. 1 is a block diagram of the present invention;
FIG. 2 is a schematic diagram of the circuit of the present invention;
FIG. 3 is a schematic diagram of a SiC MOSFET transfer characteristic curve;
FIG. 4 is a diagram of a conventional turn-on transient waveform;
FIG. 5 is a diagram of the turn-on transient waveform of the present invention;
FIG. 6 is a diagram of a conventional short-circuit protection waveform;
FIG. 7 is a diagram of a short-circuit protection waveform of the present invention;
FIG. 8 is a diagram of a conventional two-type short-circuit protection waveform;
FIG. 9 is a waveform of the second type of short circuit protection of the present invention;
the specific implementation mode is as follows:
in order that the invention may be more clearly understood, reference is now made to the following description taken in conjunction with the accompanying drawings.
The connection relationship of the units of the present invention is shown in FIG. 1.
A short circuit current suppression based SiC MOSFET short circuit protection circuit, comprising: power supply and signal isolation unit, logic unit, drive unit, short-circuit protection unit and VDSDetection unit and VGA detection unit, wherein: the first input end of the power supply and signal isolation unit is connected with a driving signal Vsw, the second input end is connected with the first output end of the short-circuit protection unit, and the first output end is connected with a fault signal VfaultA second output terminal connected to the first input terminal of the logic unit, a short-circuit protection unit connected to the second input terminal of the logic unit, a third input terminal of the logic unit connected to the second output terminal of the short-circuit protection unit, and a fourth input terminal of the logic unit connected to the second input terminal of the logic unitDSThe first output end of the detection unit is connected with the fourth input end of the logic unit and VGThe first output end of the detection unit and the third input end of the drive unit are connected, the first output end and the second output end of the logic unit are respectively connected with the first input end and the second input end of the drive unit, and the second input end of the short-circuit protection unit is connected with the VDSSecond output terminal of the detecting unit is connected with VDSThe first input end of the detection unit is connected with the drain electrode of the SiC MOSFET to be detected, and the first output end of the driving unit is connected with the VGThe first input end of the detection unit is connected with the grid electrode of the SiC MOSFET to be detected.
A schematic diagram of each unit specific device provided in this embodiment is shown in fig. 2.
The driving unit is used for providing on-off driving voltage for the grid electrode of the SiC MOSFET to be tested and reducing the driving voltage when short circuit occurs; the method comprises the following steps: NAND gate Ga1P-type MOS M1N type MOS M2P-type MOS M3N type MOS M4Gate resistance Rg1Gate resistance Rg2Gate resistance Rg3Gate resistance Rg4Diode Dg1Diode Dg2Positive driving voltage VccPositive driving voltage Vcc1Negative driving voltage VeeWherein: ga1Is connected with a drive signal Vsw， Ga1Is connected to the second input terminalFault signal Vsh，Ga1And M2Grid electrode of, M3Are connected to the gate of, M3And a positive driving voltage Vcc1Are connected to M3Drain of (1) and Rg3One end of the two ends are connected; rg3Another end of (D) andg1is connected to the anode of M2And a negative driving voltage VeeAre connected to M2Drain of (1) and Rg2Are connected at one end, M1And a positive driving voltage VccAre connected to M1Drain of (1) and Rg1Are connected at one end, M4And a positive driving voltage Vcc1Are connected to M4Drain of (1) and Rg4Are connected at one end to Rg4Another end of (D) andg2are connected to each other.
Positive drive voltage VccAnd a negative drive voltage VeeRespectively used for providing grid voltage and positive driving voltage V of the normal on and off states of the SiC MOSFET to be testedcc1Then it is used to limit the gate voltage when a short-circuit of one kind and a short-circuit of two kinds occur, and VccGreater than Vcc1；Dg1For preventing M1And M3When conducting simultaneously VccAnd Vcc1Forming a current loop, Dg2For preventing M2And M4When conducting simultaneously Vcc1And VeeForming a current loop.
To reduce the turn-on voltage drop during normal turn-on, a positive drive voltage V is setcc20V, in order to prevent crosstalk influence at turn-off, a negative driving voltage V is setee＝-5V，Vcc1Should not be too low, otherwise short-circuit fault detection will be affected, set Vcc1＝15V。
The short-circuit protection unit is used for detecting short-circuit faults and outputting fault signals, and comprises: NOT gate Ga2Diode D1Resistance R1Resistance R2Capacitor C1And a comparator U1(ii) a Wherein G isa2And the input end of the driving signal VswTo each other, Ga1And D1Are connected to the anode D1And R1One end, C1One end, R2One end is connected to R1The other end and a positive driving voltage Vcc1Are connected to each other, C1The other end is grounded, R2The other end is connected with U1Are connected to the positive input end of U1Output end of the short-circuit fault signal Vsw。
The V isDSAnd the detection unit is used for detecting the drain voltage of the SiC MOSFET to be detected, judging whether the drain voltage enters a conduction voltage drop state or not and outputting a drain state signal. The method comprises the following steps: diode D2Diode D3Diode D4Resistance R3Capacitor C2And a comparator U2(ii) a Wherein D is2The cathode of the anode is connected with the drain electrode of the SiC MOSFET to be tested, D2And D3Anode of (D)4Cathode of (2), R3One end of (A), C2One end of (U)1Negative input terminal, U2Are connected to the negative input terminal of D3And R3Another end of (1), positive drive voltage Vcc1Are connected to each other, C2Another end of (D) and4anode of (2) is grounded, U2Is connected with a reference voltage Vref1， U2Output terminal of the transistor outputs a drain detection signal Vp1。
Diode D2The high-voltage diode is formed by connecting a plurality of diodes in series and has reverse breakdown voltage higher than rated voltage, D, of the SiC MOSFET to be tested2Isolating the detection circuit from the high voltage of the drain electrode, D3、D4、R3And C2Forming a clamp circuit for limiting the comparator U2And U1Input voltage of VDSThe detection unit and the short-circuit protection unit share a diode D2 and a clamping circuit; reference voltage Vref1Less than the drive voltage Vcc1。
The V isGA detection unit for detecting the gate voltage V of the SiC MOSFET to be detectedGJudging whether a grid overvoltage spike occurs or not, and outputting a grid state signal, wherein the method comprises the following steps: NOT gate Ga3Operational amplifier U3Resistance R4Resistance R5Resistance R6And a resistance R7Wherein: ga3And M4Is connected with the grid and outputs a grid detection signal Vp2，Ga3Input terminal and U3Output terminal of R7Are connected at one end, U3Negative input terminal of and R4One end of (A), R5Are connected at one end to R4Another end of (1) and Rg1Another end of (D)g2Is connected with the grid of the SiC MOSFET to be tested, R5Is grounded at the other end, U3Positive input terminal of and R7Another end of (1), R6Are connected at one end to R6Is connected with a reference voltage V at the other endref2。
VGU in the detection unit3Has a positive supply voltage of V+Negative supply voltage of V-To reduce power in the driver board, V is set+＝Vcc1V-ground, reference voltage Vref2Is a positive value, and:
wherein: vt1Is the short-circuit reference voltage of the gate, in two types of short-circuit faults, when the gate voltage exceeds this value, VGThe detection unit judges that a short-circuit fault occurs, and at the moment U3The output voltage is composed of Vcc1Converting into 0V; vt2Is the off reference voltage of the gate, when the gate voltage is less than the value, U is3The output voltage is converted from 0V to Vcc1。
The logic unit is used for logically combining the fault signal, the drain state signal, the grid state signal and the switch signal and outputting a grid control signal to the driving unit, and can realize logic control by adopting a digital chip FPGA or a CPLD and can also realize logic control by adopting an AND/NOT gate building analog circuit; the embodiment adopts a non-gate lapThe analog circuit comprises: NAND gate Ga4AND gate Ga5AND gate Ga6And gate Ga7Wherein: ga4First input terminal, Ga5First input terminal, Ga6Is connected with Vsw，Ga4Second input terminal of (1) is connected with Vp2，Ga4And Ga5Is connected to the second input terminal of Ga5And Ga7Are connected to a first input terminal, Ga6And Ga7Is connected to the second input terminal of Ga7And M1Are connected.
This embodiment describes in detail the feasibility of the present invention based on the output characteristics of the SiC MOSFET shown in fig. 3, where the abscissa of fig. 3 is the drain-source voltage V of the SiC MOSFETDSOrdinate is the drain current I of the SiC MOSFETD. The output characteristic of the SiC MOSFET is divided into a cut-off region, a saturation region and an ohmic region, the SiC MOSFET enters the saturation region from the cut-off region in the on-transient state and then enters the ohmic region to start conducting, when one type of short circuit occurs, the SiC MOSFET always works in the saturation region after entering the saturation region from the cut-off region, and when the other type of short circuit occurs, the SiC MOSFET enters the saturation region from the ohmic region, as can be seen from the figure, the drain voltage V in the saturation regionDSUnder the same condition, the drain current IDWith the gate voltage VGIs increased, it is possible to reduce the short-circuit current of one type and the short-circuit current of two types by reducing the gate voltage.
The working principle of the present embodiment will be described with reference to fig. 2.
When the SiC MOSFET is in an off state, the drive signal Vsw is low, and M is turned off by Ga13Turn off, turn off M2On, the grid voltage is a negative driving voltage VeeAt VGIn the detection unit, U3At a negative input terminal voltage of
Less than positive input terminal voltage, thus U3At an output terminal voltage of Vcc1，Ga3Is output signal Vp2At low powerMake M flat4Is in an off state; at VDSIn the detection unit and short-circuit protection unit, Ga2Output voltage of VccThen U is1At a positive input terminal voltage of VccAnd D1Due to the difference in the drain voltage VDSIs the system bus voltage, then U1And U2Has a negative input terminal voltage of Vcc1And D3Is less than the sum of the conduction voltage drops of the comparator U1But exceeds the reference voltage Vref1Thus U is1Output voltage VshIs at a high level, U2Output voltage Vp1For low level, the logic unit will M1Turn off, and turn on M2With SiC MOSFET in the cut-off region, drain current IDIs 0.
When the driving signal Vsw is converted from low level to high level, the SiC MOSFET enters into an on transient state, and the Vsw passes through Ga1Will M2Off, M3Conducting, the driving unit provides positive driving voltage V to the gridcc1The SiC MOSFET enters a saturation region from a cut-off region, and the drain current IDStarts to rise, in the short-circuit protection unit, the change of Vsw makes Ga1Output low level, slave D1Reverse cut-off characteristic of (1), U1The positive input terminal voltage begins to fall with a time constant τ R1C1Eventually, it will drop to Vcc1The time constant τ is the blanking time of the conventional short-circuit protection method.
At drain current IDDuring the rise, the drain voltage VDSInfluenced by external stray inductances, but still at a high voltage, U, although somewhat reduced1And U2The output voltage remains constant, thus M1The gate voltage is still in the off state, but the gate voltage is not higher than V in the whole on transient state although risingccThen U is3The output voltage is also constant, Vp2Remains low, thus M4The off state is maintained.
To ensure a higher turn-on rate, Rg3Must be less than Rg1The gate voltage V of this stageGIs expressed by the following formula:
wherein C isissIs a SiC MOSFET input capacitance.
While the traditional driving method directly adopts the positive driving voltage VccThe gate is powered so that the gate voltage is:
in order to ensure that the invention does not influence the opening rate of the SiC MOSFET, the formula (3) and the formula (4) must be equal, and the resistance R is obtained by using a Taylor formulag3Has a value of about:
when the SiC MOSFET is in the normal turn-on process, the drain current IDAfter the current rises to the load current, the SiC MOSFET moves from a saturation region to an ohmic region, and the drain voltage VDSBegins to rapidly drop to the conduction voltage drop Vsat，U1And U2The negative input terminal voltage of the transformer rapidly drops and is less than U1Positive input terminal voltage sum Vref1Thus VshRemains high, and U2The voltage Vp1 at the negative output end is converted to high level, the logic unit makes M1 conductive, and the diode D receivesg1Reverse cut-off characteristic, positive drive voltage Vcc1Is turned off, and the driving unit supplies a positive driving voltage V to the gateccThe SiC MOSFET goes into normal conduction.
LTspice software is adopted to simulate the normal open-turn transient process, fig. 4 shows the traditional turn-on transient waveform, when the 5 th microsecond is reached, the SiC MOSFET is turned on, the driving unit provides 20V positive driving voltage for the grid voltage, and the turn-on time is 0.6 microsecond; fig. 5 shows a switching transient waveform of the present invention, in which the driving unit first provides a positive driving voltage of 15V to the gate voltage, and switches the driving unit to the gate voltage to a positive driving voltage of 20V after the drain voltage VDS drops to the turn-on voltage drop, and the switching-on time is also 0.6 μ s; as can be seen from a comparison of fig. 4 and 5, the rate of normal turn-on transients is not affected by the use of the present invention.
When a short circuit occurs in the SiC MOSFET, the drain current IDContinues to rise rapidly, the drain voltage VDSQuickly returns to the system bus voltage, so that the SiC MOSFET is always in the saturation region, U1And U2The negative input terminal voltage is still Vcc and D1The output of the comparator U2 is low, so that M1 is not turned on and the gate voltage is still Vcc1，IDFinally rises to the gate voltage VG＝Vcc1Maximum current value corresponding to the time, thereby restraining short-circuit current until after blanking time, U1The positive input terminal voltage is reduced to Vcc1Is less than U1At the negative input terminal voltage, the short-circuit protection unit detects a short-circuit fault, VshChange to low level so that M3Off, M2And the SiC MOSFET is turned on and driven to be turned off.
LTspice software is adopted to simulate a short circuit, FIG. 6 shows a short circuit protection waveform without short circuit current suppression, when the 5 mus is reached, the SiC MOSFET is switched on, the grid voltage is 20V, and the short circuit current I isDMaximum value of 1.17kA, SiC MOSFET is closed at 6.9 mu s, overvoltage V is turned offDSIs 330V; FIG. 7 shows a short-circuit protection waveform with a gate voltage limited to 15V, resulting in a short-circuit current IDMaximum 606A, turn off overvoltage V in turn-off transientDSIs 140V; as can be seen from comparison between fig. 8 and fig. 9, the short-circuit current suppression circuit of the present invention can effectively suppress the short-circuit current and reduce the turn-off overvoltage.
When the SiC MOSFET has a class II short circuit, the drain current IDThe sudden change of load current leads to the voltage drop VsatRises rapidly and charges the gate through the Miller capacitance, the gate voltage VGFrom VccInstantaneously rising to form a gate voltage spike when the gate voltage exceeds Vt1While, U3The output voltage is inverted to a low level so that Ga3Output voltage V ofp2Conversion to high level VccWill M4Open, while logic unit will M1Is turned off, so that the driving unit quickly pulls down the gate voltage to Vcc1Thereby inhibiting short-circuit current, and when the SiC MOSFET enters a saturation region from an ohmic region, the short-circuit protection unit detects a short-circuit fault, VshChange to low level so that M4Off, M2And the SiC MOSFET is turned on and driven to be turned off.
LTspice software is adopted to simulate two types of short circuits, FIG. 8 shows two types of short circuit protection waveforms without short circuit current suppression, at 11 mus, two types of short circuits occur, and short circuit current IDMaximum value of 1kA, SiC MOSFET is closed at 12 mu s, transient turn-off overvoltage V is turned offDSIs 287V; FIG. 9 shows two types of short-circuit protection waveforms according to the present invention, wherein the gate voltage is switched to 15V and the short-circuit current I is set when two types of short-circuits occurDMaximum value is suppressed to 422A, and transient overvoltage V is turned offDSIs 197V; as can be seen from comparison between fig. 8 and fig. 9, the class two short-circuit current suppression circuit of the present invention can effectively suppress the short-circuit current and reduce the turn-off overvoltage.
It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and all equivalent substitutions or substitutions made on the above-mentioned technical solutions belong to the scope of the present invention.
Claims (6)
1. A short circuit current suppression based SiC MOSFET short circuit protection circuit, comprising: logic unit, drive unit, short-circuit protection unit, VDSDetection unit and VGA detection unit, characterized in that:
the driving unit is used for providing on-off driving voltage for the grid electrode of the SiC MOSFET to be tested and reducing the driving voltage when short circuit occurs;
the short-circuit protection unit is used for detecting short-circuit faults and outputting fault signals;
the V isDSA detection unit for detecting the drain voltage V of the SiC MOSFET to be detectedDSJudging whether the drain voltage enters a conduction voltage drop state or not, and outputting a drain state signal;
the V isGA detection unit for detecting the gate voltage V of the SiC MOSFET to be detectedGJudging whether a grid overvoltage peak occurs or not, and outputting a grid state signal;
and the logic unit is used for logically combining the fault signal, the drain state signal, the grid state signal and the switch signal and outputting a grid control signal to the driving unit.
2. The SiC MOSFET short-circuit protection circuit based on short-circuit current suppression as claimed in claim 1, wherein the logic unit adopts a digital chip CPLD to realize logic control, or adopts an AND/NOT gate building analog circuit to realize logic control.
3. The short-circuit current suppression-based SiC MOSFET short-circuit protection circuit as claimed in claim 1, wherein said driving unit provides two positive driving voltages and one negative driving voltage, wherein the larger positive driving voltage and the negative driving voltage are respectively used for providing the gate voltage of the SiC MOSFET to be tested in the normal on and off states, and the smaller positive driving voltage is used for limiting the gate voltage when one-type short circuit and two-type short circuit occur.
4. The SiC MOSFET short-circuit protection circuit based on short-circuit current suppression as claimed in claim 3, wherein the gate resistance of the smaller positive driving voltage circuit is smaller than that of the larger positive driving voltage circuit in order to ensure the normal turn-on rate of the SiC MOSFET to be tested by the driving unit.
5. The short circuit current suppression based SiC MOSFET short circuit protection circuit of claim 1, wherein said VDSThe detection unit adopts a rapid high-voltage diode circuit to isolate the detection circuit from the high voltage of the drain electrode, and the drain electrode voltage detection unit and the short-circuit protection unit can shareWith the diode circuit.
6. The short circuit current suppression based SiC MOSFET short circuit protection circuit of claim 1, wherein said VGThe detection circuit adopts a hysteresis comparator.
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| CN201811482601.5A CN110190838A (en) | 2018-12-05 | 2018-12-05 | A kind of SiC MOSFET short-circuit protection circuit and method based on short circuit current inhibition |
| CN2018114826015 | 2018-12-05 |
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| CN211930609U true CN211930609U (en) | 2020-11-13 |
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| CN201811482601.5A Withdrawn CN110190838A (en) | 2018-12-05 | 2018-12-05 | A kind of SiC MOSFET short-circuit protection circuit and method based on short circuit current inhibition |
| CN201921850461.2U Active CN211930609U (en) | 2018-12-05 | 2019-10-30 | SiC MOSFET short-circuit protection circuit based on short-circuit current suppression |
| CN201911047961.7A Active CN110635792B (en) | 2018-12-05 | 2019-10-30 | SiC MOSFET short-circuit protection circuit and method based on short-circuit current inhibition |
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| WO2024082085A1 (en) * | 2022-10-17 | 2024-04-25 | Innoscience (suzhou) Semiconductor Co., Ltd. | Semiconductor system and method for manufacturing the same |
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| FR2809234B1 (en) * | 2000-05-22 | 2002-08-02 | Minarro Bernot Ind Diffusion C | THYRISTOR DUAL, THYRISTOR DIODE DUAL, THYSISTOR, THYSISTOR DIODE, CONVERTER AND SWITCH |
| JP3964833B2 (en) * | 2003-06-30 | 2007-08-22 | 株式会社オートネットワーク技術研究所 | Intelligent power device and load short circuit protection method thereof |
| CN101977045B (en) * | 2010-11-05 | 2012-08-22 | 美的集团有限公司 | Intelligent IGBT |
| EP4213383A1 (en) * | 2012-10-31 | 2023-07-19 | Rohm Co., Ltd. | Electronic circuit |
| JP6104660B2 (en) * | 2013-03-21 | 2017-03-29 | 本田技研工業株式会社 | Short-circuit current protection device |
| CN104917164B (en) * | 2014-03-11 | 2018-07-31 | 北京动力源科技股份有限公司 | A kind of Drive Protecting Circuit |
| JP6582471B2 (en) * | 2014-04-01 | 2019-10-02 | 富士電機株式会社 | Gate drive circuit for voltage-driven power semiconductor device |
| CN104467754A (en) * | 2014-12-23 | 2015-03-25 | 安徽大学 | MOSFET driver with short pulse suppressing function |
| CN106027011B (en) * | 2016-05-23 | 2019-04-09 | 南京航空航天大学 | Based on parasitic inductance electric current detecting method and its application |
| CN105977905B (en) * | 2016-07-04 | 2019-01-08 | 西安电子科技大学 | Over-current and over-voltage and under-voltage drive protection system based on SiC MOSFET |
| CN106099864B (en) * | 2016-07-19 | 2018-04-24 | 东南大学 | A kind of short-circuit protection method and its circuit of IGBT device for power switching |
-
2018
- 2018-12-05 CN CN201811482601.5A patent/CN110190838A/en not_active Withdrawn
-
2019
- 2019-10-30 CN CN201921850461.2U patent/CN211930609U/en active Active
- 2019-10-30 CN CN201911047961.7A patent/CN110635792B/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024082085A1 (en) * | 2022-10-17 | 2024-04-25 | Innoscience (suzhou) Semiconductor Co., Ltd. | Semiconductor system and method for manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110635792B (en) | 2023-12-15 |
| CN110190838A (en) | 2019-08-30 |
| CN110635792A (en) | 2019-12-31 |
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