CN113904669A - Silicon carbide MOS tube driving circuit - Google Patents
Silicon carbide MOS tube driving circuit Download PDFInfo
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- CN113904669A CN113904669A CN202111154716.3A CN202111154716A CN113904669A CN 113904669 A CN113904669 A CN 113904669A CN 202111154716 A CN202111154716 A CN 202111154716A CN 113904669 A CN113904669 A CN 113904669A
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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
- H03K17/08104—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to 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
Abstract
The application relates to a carborundum MOS manages drive circuit relates to the industrial automation field, and this carborundum MOS manages drive circuit includes: the driving circuit comprises a transformer, at least one driving control circuit and a silicon carbide MOS tube connected with each driving control circuit in the at least one driving control circuit; the transformer comprises primary side coils and secondary side coils, wherein the number of the primary side coils corresponds to that of the secondary side coils of the driving control circuit; the primary side coil is used for receiving input signals, each secondary side coil is connected with one drive control circuit, the drive control circuits are used for driving the silicon carbide MOS tubes to be conducted or disconnected according to drive signals provided by the secondary side coils, and the ratio of the voltage between the drive signals and the input signals is equal to the ratio of the number of turns between the secondary side coils and the primary side coils. Therefore, the silicon carbide MOS tube driving circuit is simpler in overall structure and lower in cost.
Description
Technical Field
The application relates to the field of industrial automation, in particular to a silicon carbide MOS tube driving circuit.
Background
With the development of power electronic technology, the types of MOS transistors, especially silicon carbide MOS transistors, are increasing. The high-frequency switch has the characteristics of low on-resistance, low switching loss, high working frequency, high-temperature working and the like, so that the high-frequency switch is widely applied to the field of industrial automation. However, since the driving voltage range of the silicon carbide MOS tube is-10V- +25V, the driving voltage is recommended to be-5V- +20V, while the driving voltage range of the traditional silicon MOS tube is-30V- +30V, and the driving voltage is recommended to be-15/+ 15V. Therefore, compared with the traditional silicon MOS tube, the silicon carbide MOS tube has a smaller safety threshold, and a voltage spike in the driving circuit is likely to break down an oxide layer between a grid electrode and a source electrode of the silicon carbide MOS tube, so that the silicon carbide MOS tube fails and the stability of the driving circuit is affected. However, in the conventional silicon carbide MOS transistor driving circuit, in order to solve the problem of voltage spike generated by driving waveform oscillation, a relatively complex protection circuit is usually required to be arranged, which results in a complex overall structure and a relatively high cost of the driving circuit.
Disclosure of Invention
The application provides a carborundum MOS manages drive circuit to solve current drive circuit's overall structure complicacy, the higher problem of cost.
In a first aspect, the present application provides a silicon carbide MOS transistor driving circuit, which includes: the driving circuit comprises a transformer, at least one driving control circuit and a silicon carbide MOS tube connected with each driving control circuit in the at least one driving control circuit;
the transformer comprises primary side coils and secondary side coils, wherein the number of the primary side coils corresponds to that of the secondary side coils of the driving control circuit; the primary side coil is used for receiving input signals, each secondary side coil is connected with one drive control circuit, the drive control circuits are used for driving the silicon carbide MOS tubes to be conducted or disconnected according to drive signals provided by the secondary side coils, and the ratio of the voltage between the drive signals and the input signals is equal to the ratio of the number of turns between the secondary side coils and the primary side coils.
Optionally, the driving control circuit includes a first diode, a second diode, a first triode, a first resistor, a second resistor, a third resistor, and a first capacitor;
the first end of the first resistor is connected with the first end of the secondary coil, the second end of the first resistor is connected with the anode of the first diode and the anode of the second diode respectively, the cathode of the first diode is connected with the emitter of the first triode and the first end of the second resistor respectively, the cathode of the second diode is connected with the base of the first triode, the second end of the second resistor is connected with the first end of the third resistor, the first end of the first capacitor and the grid of the silicon carbide MOS tube respectively, and the second end of the third resistor, the second end of the first capacitor, the collector of the first triode and the source of the silicon carbide MOS tube are connected with the second end of the secondary coil.
Optionally, the driving control circuit further includes a first voltage regulator tube and a second voltage regulator tube;
the cathode of the first voltage-stabilizing tube is connected with the grid electrode of the silicon carbide MOS tube, the anode of the first voltage-stabilizing tube is connected with the anode of the second voltage-stabilizing tube, and the cathode of the second voltage-stabilizing tube is connected with the source electrode of the silicon carbide MOS tube.
Optionally, the drive control circuit further comprises a fourth resistor;
the first end of the fourth resistor is connected with the base electrode of the first triode, and the second end of the fourth resistor is connected with the source electrode of the silicon carbide MOS tube.
Optionally, the drive control circuit further includes a fifth resistor, a sixth resistor, and a second capacitor, which are arranged in parallel;
the first end of the fifth resistor, the first end of the sixth resistor and the first end of the second capacitor are respectively connected with the second end of the first resistor, and the second end of the fifth resistor, the second end of the sixth resistor and the second end of the second capacitor are respectively connected with the first end of the fourth resistor;
the resistance value of the fourth resistor is greater than the sum of the resistance values of the fifth resistor, the sixth resistor and the first resistor.
Optionally, the drive control circuit further comprises a seventh resistor;
the first end of the seventh resistor is connected with the collector of the first triode, and the second end of the seventh resistor is connected with the second end of the secondary coil.
Optionally, the drive control circuit further includes a third voltage regulator tube and a third capacitor;
and the anode of the third voltage-regulator tube and the first end of the third capacitor are both connected with the collector of the first triode, and the cathode of the third voltage-regulator tube and the second end of the third capacitor are both connected with the second end of the secondary coil.
Optionally, the first resistor and the second resistor are variable resistors, and a resistance value of the third resistor is greater than a sum of resistance values of the first resistor and the second resistor.
Optionally, the number of the driving control circuits is two, the directions of currents in the two secondary coils connected to the two driving control circuits are opposite, and the ratio of the number of turns of the two secondary coils to the number of turns of the primary coil is 1: 1.
Optionally, the silicon carbide MOS transistor driving circuit further includes a fourth capacitor and a fifth capacitor;
the fourth capacitor and the fifth capacitor are respectively arranged at two ends of the primary coil.
In an embodiment of the present application, the silicon carbide MOS transistor driving circuit includes: the driving circuit comprises a transformer, at least one driving control circuit and a silicon carbide MOS tube connected with each driving control circuit in the at least one driving control circuit; the transformer comprises primary side coils and secondary side coils, wherein the number of the primary side coils corresponds to that of the secondary side coils of the driving control circuit; the primary side coil is used for receiving input signals, each secondary side coil is connected with one drive control circuit, the drive control circuits are used for driving the silicon carbide MOS tubes to be conducted or disconnected according to drive signals provided by the secondary side coils, and the ratio of the voltage between the drive signals and the input signals is equal to the ratio of the number of turns between the secondary side coils and the primary side coils. That is to say, the silicon carbide MOS transistor driving circuit can realize the isolation of the driving signal by the transformer instead of the photocoupler, and can set one or more driving control circuits on the secondary side of the transformer according to the actual requirement, and drive the on and off states of the silicon carbide MOS transistor by each driving control circuit, thereby realizing one-way or multi-way driving control. Therefore, compared with the mode that a plurality of photoelectric couplers are connected with a plurality of driving control circuits, the silicon carbide MOS tube driving circuit is simpler in overall structure and lower in cost.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
Fig. 1 is a schematic structural diagram of a silicon carbide MOS transistor driving circuit according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a driving control circuit according to an embodiment of the present disclosure;
fig. 3 is a second schematic structural diagram of a silicon carbide MOS transistor driving circuit according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a silicon carbide MOS transistor driving circuit according to an embodiment of the present application. As shown in fig. 1, the silicon carbide MOS transistor driving circuit includes: the driving circuit comprises a transformer 100, at least one driving control circuit 200 and a silicon carbide MOS tube 300 connected with each driving control circuit 200 in the at least one driving control circuit 200;
the transformer 100 includes primary windings and secondary windings corresponding to the number of the driving control circuits 200; the primary side coils are used for receiving input signals, each secondary side coil is connected with one driving control circuit 200, the driving control circuits 200 are used for driving the silicon carbide MOS tube 300 to be switched on or switched off according to driving signals provided by the secondary side coils, and the ratio of the voltage between the driving signals and the input signals is equal to the ratio of the number of turns between the secondary side coils and the primary side coils.
Specifically, the number of the driving control circuits 200 may be one, or may be multiple, and may be specifically set according to actual needs, which is not specifically limited in this application. The number of the secondary windings and the number of the silicon carbide MOS transistors 300 correspond to the number of the drive control circuits 200, respectively.
The primary winding of the transformer 100 is used for receiving an input signal and generating an ac magnetic flux through a magnetic core of the transformer 100, so that a driving signal is induced in the secondary winding, and thus, each driving control circuit 200 can control the on/off of the silicon carbide MOS transistor 300 connected thereto through the driving signal. Compared with the existing driving circuit in which a photoelectric coupler is adopted to transmit input signals, the mode can simplify the single-path structure of the driving circuit and save the cost.
In practical application, the number of the secondary coil, the drive control circuit and the silicon carbide MOS tube in the silicon carbide MOS tube drive circuit can be set according to the practical use scene of the silicon carbide MOS tube drive circuit. For example, when the main circuit needs a silicon carbide MOS transistor to realize the on-off control of the LED lamp, only one secondary coil, one driving control circuit, and one silicon carbide MOS transistor need to be arranged in the silicon carbide MOS transistor driving circuit; when the main circuit needs two silicon carbide MOS tubes for DC-DC control, two secondary coils, two drive control circuits and two silicon carbide MOS tubes are needed to be arranged in the silicon carbide MOS tube drive circuit. When the silicon carbide MOS tube driving circuit needs to drive a plurality of silicon carbide MOS tubes, the transmission of multiple paths of driving signals can be realized only by one transformer, and therefore, the whole structure of the whole silicon carbide MOS tube driving circuit is further simplified.
In this embodiment, the silicon carbide MOS transistor driving circuit may implement isolation of driving signals by the transformer 100 instead of a photocoupler, and may set one or more driving control circuits 200 on the secondary side of the transformer 100 according to actual needs, and drive the on and off states of the silicon carbide MOS transistor 300 by each driving control circuit 200, thereby implementing one-way or multi-way driving control. Therefore, compared with the mode of connecting a plurality of photoelectric couplers with a plurality of drive control circuits 200, the silicon carbide MOS tube drive circuit has a simpler overall structure and lower cost.
Further, referring to fig. 2, fig. 2 is a schematic structural diagram of a driving control circuit according to an embodiment of the present disclosure. As shown in fig. 2, the driving control circuit 200 includes a first diode D1, a second diode D2, a first transistor Q1, a first resistor R1, a second resistor R11, a third resistor R13, and a first capacitor C7;
a first end of the first resistor R1 is connected to a first end of the secondary coil, a second end of the first resistor R1 is connected to an anode of the first diode D1 and an anode of the second diode D2, a cathode of the first diode D1 is connected to an emitter of the first triode Q1 and a first end of the second resistor R11, a cathode of the second diode D2 is connected to a base of the first triode Q1, a second end of the second resistor R11 is connected to a first end of the third resistor R13, a first end of the first capacitor C7 and a gate of the silicon carbide MOS transistor Q3, and a second end of the third resistor R13, a second end of the first capacitor C7, a collector of the first triode Q1 and a source of the silicon carbide MOS transistor Q3 are connected to a second end of the secondary coil.
Specifically, the input signal is usually a Pulse Width Modulation (PWM) signal, and thus the driving signal is also a PWM signal. When the signal received by the first end of the secondary winding is at a high level and the signal received by the second end of the secondary winding is at a low level, the first diode D1 and the second diode D2 are both in a conducting state, and since the conducting voltage drops of the first diode D1 and the second diode D2 are the same, the base and emitter of the first triode Q1 are at the same potential, and the first triode Q1 is in a blocking state. At this time, the driving current may rapidly charge the first capacitor C7 through the first resistor R1, the first diode D1, the second resistor R11, and the third resistor R13, and when the voltage across the first capacitor C7 is greater than the turn-on voltage of the silicon carbide MOS transistor Q3, the silicon carbide MOS transistor Q3 may rapidly switch to the on state. In addition, in the conducting process of the silicon carbide MOS transistor Q3, the third resistor R13 and the first capacitor C7 may further form an RC low-pass filter circuit, which may filter the high-frequency interference of the driving signal and prevent the silicon carbide MOS transistor Q3 from being turned on by mistake.
When the signal connected to the first end of the secondary winding changes from high level to low level and the signal connected to the second end of the secondary winding changes from low level to high level, the first diode D1 and the second diode D2 switch to reverse cut-off state, and at this time, the silicon carbide MOS transistor Q3 changes from on state to off state. At the moment that the silicon carbide MOS transistor Q3 is switched from the on state to the off state, the voltage stored in the first capacitor C7 can make the first triode Q1 be always in the saturated on state in the process of switching off the silicon carbide MOS transistor Q3, so as to achieve the effect of rapidly discharging the first capacitor C7, and further make the voltage between the gate and the source of the silicon carbide MOS transistor Q3 rapidly drop to 0V, so that the silicon carbide MOS transistor Q3 is rapidly switched off.
In this embodiment, the driving control circuit 200 can control the on or off state of the silicon carbide MOS transistor Q3 according to the level jump of the driving signal, and since the first diode D1 and the second diode D2 are disposed at the emitter and the base of the first transistor Q1, the on or off state of the first transistor Q1 can be accelerated, so as to realize the fast charging and fast discharging of the first capacitor C7, thereby realizing the fast on and off function of the silicon carbide MOS transistor Q3.
Further, with continued reference to fig. 2, the driving control circuit 200 further includes a first voltage regulator VD1 and a second voltage regulator VD 2;
the cathode of the first voltage-regulator tube VD1 is connected with the grid of the silicon carbide MOS tube Q3, the anode of the first voltage-regulator tube VD1 is connected with the anode of the second voltage-regulator tube VD2, and the cathode of the second voltage-regulator tube VD2 is connected with the source electrode of the silicon carbide MOS tube Q3.
Specifically, the stabilized voltage of the first voltage regulator VD1 and the stabilized voltage of the second voltage regulator VD2 may be set according to the type of the silicon carbide MOS transistor Q3, and the stabilized voltage of the first voltage regulator VD1 may be greater than the stabilized voltage of the second voltage regulator VD 2. For example, assuming that the driving voltage of the silicon carbide MOS transistor Q3 ranges from-5V to +24V, the stabilized voltage of the first voltage regulator VD1 may be set to +24V, and the stabilized voltage of the second voltage regulator VD2 may be set to +5V, so that the driving voltage may be clamped between-5V and +24V, and the damage to the silicon carbide MOS transistor Q3 due to the gate voltage being too high due to abnormal driving signals is avoided.
Further, the driving control circuit 200 further includes a fourth resistor R7;
a first end of the fourth resistor R7 is connected to the base of the first transistor Q1, and a second end of the fourth resistor R7 is connected to the source of the silicon carbide MOS transistor Q3. Thus, the fourth resistor R7 can serve as a current limiting resistor of the second diode D2, and can prevent the second diode D2 from being broken down due to an excessive on-current of the second diode D2.
Further, the driving control circuit 200 further includes a fifth resistor R3, a sixth resistor R4 and a second capacitor C3 arranged in parallel;
a first end of the fifth resistor R3, a first end of the sixth resistor R4 and a first end of the second capacitor C3 are respectively connected with a second end of the first resistor R1, and a second end of the fifth resistor R3, a second end of the sixth resistor R4 and a second end of the second capacitor C3 are respectively connected with a first end of the fourth resistor R7;
the resistance value of the fourth resistor R7 is greater than the sum of the resistance values of the fifth resistor R3, the sixth resistor R4 and the first resistor R1.
Specifically, when the signal connected to the first end of the secondary winding jumps from high level to low level 0V, and the signal connected to the second end of the secondary winding jumps from low level to high level +18V, the first diode D1 and the second diode D2 switch to a reverse blocking state, the inductive current of the secondary winding can only be released through the loop formed by the fourth resistor R7, the fifth resistor R3, the sixth resistor R4 and the first resistor R1, and since the resistance of the fourth resistor R7 is much greater than the sum of the resistances of the fifth resistor R3, the sixth resistor R4 and the first resistor R1, the base voltage of the first transistor Q1 can be about-18V, and at the moment when the silicon carbide MOS transistor Q3 switches from on to off, the voltage stored in the first capacitor C7 is +18V, and the resistance of the third resistor R13 is much greater than the resistance of the second resistor R11, so that the emitter voltage of the first transistor Q1 is about +18V, the first triode Q1Q1 is always in a saturated conduction state in the process of turning off the silicon carbide MOS transistor Q3, so as to achieve the effect of rapidly discharging the first capacitor C7. In addition, in the turn-off process of the silicon carbide MOS transistor Q3, an inductive current discharge loop of the secondary coil and a discharge loop of the first capacitor C7 are mutually independent, so that the problem of vibration of a driving waveform in the turn-off process of the silicon carbide MOS transistor Q3 is solved, and the stability of the silicon carbide MOS transistor driving circuit is further improved.
Further, the driving control circuit 200 further includes a seventh resistor R9;
a first end of the seventh resistor R9 is connected to the collector of the first transistor Q1, and a second end of the seventh resistor R9 is connected to the second end of the secondary winding.
In an embodiment, when the silicon carbide MOS transistor Q3 is of a 0V voltage turn-off type, the seventh resistor R9 may be connected between the collector of the first transistor Q1 and the second end of the secondary winding, so that when the first capacitor C7 is discharged, the current of the first capacitor C7 may be discharged through the second resistor R11, the first transistor Q1 and the seventh resistor R9, and a turn-off signal of a voltage of 0V is obtained, so as to turn off the silicon carbide MOS transistor Q3.
Further, the driving control circuit 200 further includes a third regulator D5 and a third capacitor C5;
an anode of the third regulator tube D5 and a first end of the third capacitor C5 are both connected to a collector of the first triode Q1, and a cathode of the third regulator tube D5 and a second end of the third capacitor C5 are both connected to a second end of the secondary winding.
In an embodiment, when the silicon carbide MOS transistor Q3 is of a negative-voltage turn-off type, the third voltage-regulator tube D5 and the third capacitor C5 may be connected between the collector of the first triode Q1 and the second end of the secondary winding, so that when the first capacitor C7 is discharged, the current of the first capacitor C7 may be discharged through the second resistor R11, the first triode Q1, the third voltage-regulator tube D5, and the third capacitor C5, and since the third voltage-regulator tube D5 may stabilize the voltage at the two ends of the third capacitor C5 at a constant voltage, a turn-off signal with a negative voltage is obtained, and the silicon carbide MOS transistor Q3 is turned off.
Further, the first resistor R1 and the second resistor R11 are variable resistors, and the resistance value of the third resistor R13 is greater than the sum of the resistance values of the first resistor R1 and the second resistor R11.
In an embodiment, the first resistor R1 is an on-resistance of the sic MOS transistor driving circuit, so that the on-time of the sic MOS transistor Q3 can be adjusted by adjusting the resistance of the first resistor R1. The second resistor R11 is the turn-off resistor of the sic MOS transistor driving circuit, so that the turn-off time of the sic MOS transistor Q3 can be adjusted by adjusting the resistance of the second resistor R11. In addition, since the resistance value of the third resistor R13 is greater than the sum of the resistance values of the first resistor R1 and the second resistor R11, when the first capacitor C7 is charged, the charging voltage of the first capacitor C7 can be made higher, so as to ensure that the silicon carbide MOS transistor Q3 can be turned on quickly.
Further, referring to fig. 3, fig. 3 is a second schematic structural diagram of a silicon carbide MOS transistor driving circuit according to an embodiment of the present application. As shown in fig. 3, the number of the driving control circuits 200 is two, the directions of currents in the two secondary windings connected to the two driving control circuits 200 are opposite, and the ratio of the number of turns of the two secondary windings to the number of turns of the primary winding is 1: 1.
IN one embodiment, a primary coil of the transformer T1 is connected with an input signal, a homonymous terminal of the primary coil is an input signal IN _ L, and a heteronymous terminal of the primary coil is an input signal IN _ H, the design method has an interlocking function, and can prevent the upper and lower silicon carbide MOS tubes Q3 and Q4 from being broken down when the input signal IN _ H, IN _ L is at a high level; the two sets of secondary windings of the transformer T1 are the same, and the turn ratio of the primary winding to the secondary winding is 1: 1. As shown in fig. 3, the synonym terminal of the first set of secondary side coils is the positive electrode of the gate signal of the silicon carbide MOS transistor Q3, the synonym terminal of the first set of secondary side coils is the negative electrode of the gate signal of the silicon carbide MOS transistor Q3, the synonym terminal of the second set of secondary side coils is the positive electrode of the gate signal of the silicon carbide MOS transistor Q4, and the synonym terminal of the second set of secondary side coils is the negative electrode of the gate signal of the silicon carbide MOS transistor Q4. Therefore, when the input signal is a PWM signal, two paths of mutually isolated and complementary PWM driving signals can be obtained, and the voltage ranges of the driving voltages are the same. When the silicon carbide MOS tube Q3 is in an on state, the silicon carbide MOS tube Q4 is in an off state; when the silicon carbide MOS tube Q3 is in an off state, the silicon carbide MOS tube Q4 is in an on state.
In this embodiment, two silicon carbide MOS transistors are provided for driving, so as to realize the dc-to-dc conversion function of the dc bus bar through the circuit. The drain of the silicon carbide MOS transistor Q3 and the source of the silicon carbide MOS transistor Q4 are respectively connected to two ends of the dc bus bar (i.e., a P input end and an N input end in fig. 3), the source of the silicon carbide MOS transistor Q3 and the drain of the silicon carbide MOS transistor Q4 are jointly used as an output end (i.e., an OUT output end in fig. 3), and thus, the voltage value of the output end can be input to a control chip, the control chip analyzes whether the voltage value of the output end is consistent with a preset voltage value, and generates an input signal, i.e., a PWM signal with different duty ratios, by analyzing the result, and controls the on or off of the silicon carbide MOS transistor Q3 and the silicon carbide MOS transistor Q4 by the input signal, so that the output end outputs the preset voltage value. For example, if the voltage of the dc bus is 538V and a dc voltage of 48V needs to be obtained, the drain of the silicon carbide MOS transistor Q3 and the source of the silicon carbide MOS transistor Q4 may be connected to the two ends of the dc bus respectively (assuming that the voltage of the P end is 538V and the voltage of the N end is 0V), and then the on/off of the silicon carbide MOS transistor Q3 and the silicon carbide MOS transistor Q4 may be controlled by controlling the duty ratio of the high and low levels of the input signal, and finally, a dc voltage of 48V may be output from the OUT output terminal.
Further, the silicon carbide MOS tube driving circuit further comprises a fourth capacitor C1 and a fifth capacitor C2;
the fourth capacitor C1 and the fifth capacitor C2 are respectively disposed at two ends of the primary coil.
IN an embodiment, a fourth capacitor C1 and a fifth capacitor C2 may be respectively disposed at two ends of the primary coil, and the fourth capacitor C1 and the fifth capacitor C2 may filter the input signals IN _ H and IN _ L to remove high-frequency interference and direct-current components IN the input signals, so that the induced driving signals are more stable, thereby reducing voltage spikes IN the silicon carbide MOS transistor driving circuit and improving stability IN the driving circuit.
In an embodiment, a silicon carbide MOS transistor with a driving voltage of 0V to +18V is taken as an example, and is described in detail with reference to fig. 3.
The fourth capacitor C1 is an input signal IN _ H filter capacitor, one end of which is connected to pin 10 of the transformer, and the other end of which is connected to the input signal IN _ H, the fifth capacitor C2 is an input signal IN _ L filter capacitor, one end of which is connected to pin 7 of the transformer, and the other end of which is connected to the input signal IN _ L, and the fourth capacitor C1 and the fifth capacitor C2 function to filter high frequency interference and dc components IN the input signal. T1 is the transformer, has replaced the drive opto-coupler, has simplified circuit structure, has reduced the design cost. The transformer T17/10 is a primary winding, 5/6 is a first secondary winding, 1/2 is a second secondary winding, the turn ratio is 1:1:1, when an input signal IN _ H, IN _ L is a square wave signal of 0V to +18V, two paths of mutually isolated driving signals can be obtained at the secondary side, the voltage of the driving signals is-18V to +18V, the design can ensure that when the input signals IN _ H and IN _ L are both high level, an output signal is OV, and the breakdown caused by the direct connection of a silicon carbide MOS tube Q3 and a silicon carbide MOS tube Q4 is avoided. The 6 feet of the first secondary coil are connected with a first resistor R1, the 5 feet of the first secondary coil are connected with the source electrode of the silicon carbide MOS tube Q3, the first resistor R1 is a driving circuit switching-on resistor, the resistance value of the first resistor R1 determines the switching-on time of the silicon carbide MOS tube Q3, and the switching loss of the silicon carbide MOS tube Q3 is further influenced. The other end of the first resistor R1 is connected to anodes of a first diode D1 and a second diode D2, and is also connected to a fifth resistor R3, a sixth resistor R4 and a second capacitor C3, the other end of the first diode D1 is connected to an emitter of the first transistor Q1, the other end of the second diode D2 is connected to a base of the first transistor Q1, the first diode D1 and the second diode D2 are always in a forward conducting state during the turn-on of the silicon carbide MOS transistor Q3, and since the models of the first diode D1 and the second diode D2 are the same, the tube drops of the first diode D1 and the second diode D2 are equal during the turn-on, the base voltage of the first transistor Q1 is the same as the collector voltage, and the first diode Q1 is always in a turn-off state during the turn-on of the silicon carbide MOS transistor Q3. The fourth resistor R7 is a current-limiting resistor of the second diode D2, one end of which is connected to the base of the first transistor Q1, and the other end of which is connected to the source of the silicon carbide MOS transistor Q3, and functions to prevent the on-state current of the second diode D2 from breaking down the second diode D2. The first triode Q1 is a PNP triode, the base of the first triode Q1 is connected with the cathode of the second diode D2, the fourth resistor R7, the fifth resistor R3, the sixth resistor R4 and the second capacitor C3, the emitter of the first triode Q1 is connected with the cathode of the first diode D1 and the second resistor R11, the collector of the first triode Q8925 is connected with the anode of the third voltage regulator D5, the third capacitor C5 and the seventh resistor R9, and the silicon carbide MOS transistor Q3 is of a 0V voltage turn-off type, so that the seventh resistor R9 is selected as a loop of the collector of the first triode Q1, and the third voltage regulator D5 and the third capacitor C5 are reserved. The first triode Q1 is in a cut-off state during the turn-on process of the silicon carbide MOS transistor Q3, and is in a saturation conducting state during the turn-off process of the silicon carbide MOS transistor Q3. The second resistor R11 is a driving circuit turn-off resistor, one end of the second resistor R11 is connected to an emitter of the first triode Q1, the other end of the second resistor R11 is connected to the third resistor R13 and the first capacitor C7, the resistance value of the second resistor R53957 determines the turn-off time of the silicon carbide MOS transistor Q3, and further affects the switching loss of the silicon carbide MOS transistor Q3, the other ends of the third resistor R13 and the first capacitor C7 are connected to the source of the silicon carbide MOS transistor Q3, so that in the turn-on process of the silicon carbide MOS transistor Q3, the pin 6 on the first secondary side of the transformer T1 is at a high level, the pin 5 is at a low level, the driving current is charged to the first capacitor C7 through the first resistor R1, the first diode D1, the second resistor R11 and the third resistor R13, the resistance value of the third resistor R13 is much larger than the sum of the first resistor R1 and the second resistor R11, and a turn-on signal with a voltage of +18V can be obtained; the cathode of the first voltage-regulator tube VD1 is connected with the grid of the silicon carbide MOS tube Q3, the anode of the first voltage-regulator tube VD1 is connected with the anode of the second voltage-regulator tube VD2, the cathode of the second voltage-regulator tube VD2 is connected with the source electrode of the silicon carbide MOS tube Q3, the stable voltage of the first voltage-regulator tube VD1 is +24V, the stable voltage of the second voltage-regulator tube VD2 is +5V, when a driving signal is abnormal, the driving voltage can be clamped between-5V and +24V, and the silicon carbide MOS tube is prevented from being damaged due to the fact that the gate voltage is too high.
During the turn-off of the sic MOS transistor Q3, pin 6 of the first secondary winding of the transformer T1 is at a low level, pin 5 is at a high level, the diode first diode D1 and the diode second diode D2 are in a reverse cut-off state, the inductive current of the first secondary winding can only be released through the loop of the fourth resistor R7, the fifth resistor R3, the sixth resistor R4 and the first resistor R1, and the resistance of the fourth resistor R7 is much greater than the sum of the resistances of the fifth resistor R3, the sixth resistor R4 and the first resistor R1, so that the base voltage of the first triode Q1 is about-18V, and at the moment when the sic MOS transistor Q3 is switched from on to off, the voltage stored in the first capacitor C7 is +18V, and the resistance of the third resistor R13 and the second resistor R11 are much greater than the resistance of the transistor Q1 is about +18V, so that the emitter voltage of the first triode Q1 is always in a saturated on state when the sic transistor Q3 is in a saturated on state, so as to achieve the effect of fast discharging the first capacitor C7, and further obtain the turn-off signal with the voltage of 0V. In addition, in the turn-off process, an inductive current leakage loop of the first secondary coil and a leakage loop of the first capacitor C7 are mutually independent, so that the problem that the driving waveform vibrates in the turn-off process is solved.
The pin 1 of the second secondary winding is connected to the on-resistance R2 of the driving control circuit 200, and the pin 2 of the second secondary winding is connected to the source of the silicon carbide MOS transistor Q4.
By adopting the silicon carbide MOS tube driving circuit, the following beneficial effects can be obtained:
1. the transformer is used for replacing a photoelectric coupler, so that the circuit structure is simplified, the cost is saved, and the breakdown caused by the direct connection of two silicon carbide MOS (metal oxide semiconductor) tubes can be avoided through the interlocking of input signals;
2. the first triode can be ensured to be in a cut-off state in the conduction process of the silicon carbide MOS tube by introducing the first diode and the second diode, so that the problem that the driving waveform vibrates in the conduction process of the silicon carbide MOS tube is solved;
3. by introducing the first diode and the second diode, the discharge loop of the secondary coil of the transformer and the first capacitor discharge loop can be mutually independent in the turn-off process of the silicon carbide MOS tube, so that the problem that the driving waveform of the silicon carbide MOS tube vibrates in the turn-off process is solved;
4. the first capacitor is added in the driving circuit, so that high-frequency interference in a driving signal is filtered, the silicon carbide MOS tube is prevented from being switched on by mistake, and the first triode is used for discharging rapidly in the switching-off process, so that the switching loss is reduced to a great extent;
5. the first voltage regulator tube and the second voltage regulator tube are added into the driving circuit, so that the gate driving voltage can be clamped between-5V and +24V, and the silicon carbide MOS tube is prevented from being damaged due to too high gate voltage.
It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A silicon carbide MOS tube driving circuit is characterized by comprising: the driving circuit comprises a transformer, at least one driving control circuit and a silicon carbide MOS tube connected with each driving control circuit in the at least one driving control circuit;
the transformer comprises primary side coils and secondary side coils, wherein the number of the primary side coils corresponds to that of the secondary side coils of the driving control circuit; the primary side coil is used for receiving input signals, each secondary side coil is connected with one drive control circuit, the drive control circuits are used for driving the silicon carbide MOS tubes to be conducted or disconnected according to drive signals provided by the secondary side coils, and the ratio of the voltage between the drive signals and the input signals is equal to the ratio of the number of turns between the secondary side coils and the primary side coils.
2. The silicon carbide MOS transistor driving circuit as claimed in claim 1, wherein the driving control circuit comprises a first diode, a second diode, a first triode, a first resistor, a second resistor, a third resistor and a first capacitor;
the first end of the first resistor is connected with the first end of the secondary coil, the second end of the first resistor is connected with the anode of the first diode and the anode of the second diode respectively, the cathode of the first diode is connected with the emitter of the first triode and the first end of the second resistor respectively, the cathode of the second diode is connected with the base of the first triode, the second end of the second resistor is connected with the first end of the third resistor, the first end of the first capacitor and the grid of the silicon carbide MOS tube respectively, and the second end of the third resistor, the second end of the first capacitor, the collector of the first triode and the source of the silicon carbide MOS tube are connected with the second end of the secondary coil.
3. The silicon carbide MOS transistor driving circuit as claimed in claim 2, wherein the driving control circuit further comprises a first voltage regulator and a second voltage regulator;
the cathode of the first voltage-stabilizing tube is connected with the grid electrode of the silicon carbide MOS tube, the anode of the first voltage-stabilizing tube is connected with the anode of the second voltage-stabilizing tube, and the cathode of the second voltage-stabilizing tube is connected with the source electrode of the silicon carbide MOS tube.
4. The silicon carbide MOS transistor driving circuit of claim 2, wherein the driving control circuit further comprises a fourth resistor;
the first end of the fourth resistor is connected with the base electrode of the first triode, and the second end of the fourth resistor is connected with the source electrode of the silicon carbide MOS tube.
5. The SiC MOS transistor driver circuit of claim 4, wherein the drive control circuit further comprises a fifth resistor, a sixth resistor and a second capacitor arranged in parallel;
the first end of the fifth resistor, the first end of the sixth resistor and the first end of the second capacitor are respectively connected with the second end of the first resistor, and the second end of the fifth resistor, the second end of the sixth resistor and the second end of the second capacitor are respectively connected with the first end of the fourth resistor;
the resistance value of the fourth resistor is greater than the sum of the resistance values of the fifth resistor, the sixth resistor and the first resistor.
6. The silicon carbide MOS transistor driving circuit of claim 2, wherein the driving control circuit further comprises a seventh resistor;
the first end of the seventh resistor is connected with the collector of the first triode, and the second end of the seventh resistor is connected with the second end of the secondary coil.
7. The silicon carbide MOS transistor driving circuit as claimed in claim 2, wherein the driving control circuit further comprises a third voltage regulator and a third capacitor;
and the anode of the third voltage-regulator tube and the first end of the third capacitor are both connected with the collector of the first triode, and the cathode of the third voltage-regulator tube and the second end of the third capacitor are both connected with the second end of the secondary coil.
8. The silicon carbide MOS transistor driving circuit as claimed in claim 2, wherein the first resistor and the second resistor are variable resistors, and the third resistor has a resistance value greater than a sum of the resistance values of the first resistor and the second resistor.
9. The silicon carbide MOS transistor driving circuit as claimed in claim 1, wherein the number of the driving control circuits is two, the directions of currents in the two secondary windings connected to the two driving control circuits are opposite, and the ratio of the number of turns of the two secondary windings to the number of turns of the primary winding is 1: 1.
10. The silicon carbide MOS transistor driving circuit as claimed in claim 1, further comprising a fourth capacitor and a fifth capacitor;
the fourth capacitor and the fifth capacitor are respectively arranged at two ends of the primary coil.
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| CN202111154716.3A CN113904669A (en) | 2021-09-29 | 2021-09-29 | Silicon carbide MOS tube driving circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116260321A (en) * | 2023-05-16 | 2023-06-13 | 杭州锐健医疗科技有限公司 | MOS tube driving circuit, switching power supply and ablation equipment |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116260321A (en) * | 2023-05-16 | 2023-06-13 | 杭州锐健医疗科技有限公司 | MOS tube driving circuit, switching power supply and ablation equipment |
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