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CN-115133917-B - Power tube driving circuit and power tube driving method

CN115133917BCN 115133917 BCN115133917 BCN 115133917BCN-115133917-B

Abstract

The present disclosure relates to a power tube driving circuit and a power tube driving method. The power tube driving circuit comprises an input module, an output module and a transformer, wherein the input module is connected with the output module through the transformer, the input module is used for controlling the primary end of the transformer to generate alternating current according to the acquired input signal, and the output module is used for receiving a voltage signal of the secondary end of the transformer and controlling the power tube to be opened and closed according to the received voltage signal. The input module comprises a control module and a current limiting resistance module, wherein the control module is used for outputting a control signal according to the magnitude of the power supply voltage, and the current limiting resistance module is used for adjusting the magnitude of the current limiting resistance value in the input module according to the control signal so that the current limiting resistance value is increased along with the increase of the power supply voltage. When the power supply voltage is smaller, the current limiting resistance value is smaller, so that the driving current is ensured to be large enough, and effective sending and receiving of signals are realized. Along with the increase of the power supply voltage, the current limiting resistor is increased, so that the driving current is reduced, and the power consumption of the chip is reduced.

Inventors

  • WANG WENQING
  • CHEN QIANGQIANG

Assignees

  • 比亚迪半导体股份有限公司

Dates

Publication Date
20260505
Application Date
20210329

Claims (11)

  1. 1. The power tube driving circuit is characterized by comprising an input module (10), an output module (20) and a transformer (30), wherein the input module (10) and the output module (20) are connected through the transformer (30), the input module (10) is used for controlling the primary end of the transformer (30) to generate alternating current according to an acquired input signal, the output module (20) is used for receiving a voltage signal of the secondary end of the transformer (30) and controlling the opening and closing of a power tube according to the received voltage signal, Wherein the input module (10) comprises: a control module (11) for outputting a control signal according to the magnitude of the power supply voltage; The current limiting resistance module (12) is used for adjusting the magnitude of a current limiting resistance value in the input module (10) according to the control signal so that the current limiting resistance value increases along with the increase of the power supply voltage; The input part (101) receives an input signal and then inputs the input signal into the NAND gate (Q2) through the inverter (Q1), the signal generated by the frequency generation module is also input into the NAND gate (Q2), the output of the NAND gate (Q2) is input into the grid electrode of the first switch tube (Q4) after passing through the buffer (Q3), the source electrode of the first switch tube (Q4) is connected with the drain electrode of the second switch tube (Q5) and connected with one end of the isolator (103) in parallel, the grid electrode of the second switch tube (Q5) inputs the input signal, and the source electrode of the second switch tube (Q5) is connected with the other end of the isolator (103) and connected with a ground wire; the control module (11) is connected between a power supply and a ground wire, and the current limiting resistor module (12) is connected between the power supply and the drain electrode of the first switching tube (Q4).
  2. 2. The power tube driving circuit according to claim 1, wherein the current limiting resistor module (12) comprises a first preset resistor (R0), n parallel resistors (R11-R1 n) and n parallel switching tubes (PM 11-PM 1 n), the n parallel resistors and the n parallel switching tubes are in one-to-one correspondence, each parallel resistor and the corresponding parallel switching tube are connected in series and then connected in parallel with the first preset resistor (R0), the parallel resistor is the current limiting resistor in the input module (10), The control signals comprise n sub-signals, the n sub-signals are received by the n parallel switching tubes in a one-to-one correspondence mode, and each parallel switching tube is used for controlling on-off of a source electrode and a drain electrode according to the sub-signals received by the grid electrode.
  3. 3. The power tube driving circuit according to claim 1, wherein the current limiting resistor module (12) comprises a first preset resistor (R0), n series resistors (R21-R2 n) and n series switching tubes (PM 21-PM 2 n), the n series resistors and the n series switching tubes are in one-to-one correspondence, each series resistor is connected in parallel with the corresponding series switching tube, the first preset resistor and the n series resistors are connected in series, the series resistors are current limiting resistors in the input module (10), The control signals comprise n sub-signals, the n sub-signals are received by the n series switching tubes in a one-to-one correspondence mode, and each series switching tube is used for controlling on-off of a source electrode and a drain electrode according to the sub-signals received by the grid electrode.
  4. 4. The power tube driving circuit according to claim 1, wherein the current limiting resistor module (12) comprises a parallel connection part and a series connection part, the parallel connection part comprises a first preset resistor (R0), m mixed parallel resistors (R31-R3 m) and m mixed parallel switching tubes (PM 31-PM 3 m), the m mixed parallel resistors and the m mixed parallel switching tubes are in one-to-one correspondence, each mixed parallel resistor and the corresponding mixed parallel switching tube are connected in series and then connected in parallel with the first preset resistor (R0), The series part comprises (n-m) mixed series switching tubes (PM 3 (m+1) -PM 3 n) and (n-m) mixed series resistors (R3 (m+1) -R3 n) which are connected in series, the (n-m) mixed series resistors are in one-to-one correspondence with the (n-m) mixed series switching tubes, each mixed series resistor is connected in parallel with the corresponding mixed series switching tube, The resistance of the parallel connection part and the series connection part after being connected in series is a current limiting resistance in the input module (10), The control signals comprise n sub-signals, the n sub-signals are received by the m mixed parallel switching tubes and the (n-m) mixed serial switching tubes in a one-to-one correspondence mode, and each mixed parallel switching tube and each mixed serial switching tube are used for controlling on-off of a source electrode and a drain electrode according to the sub-signals received by a grid electrode.
  5. 5. The power tube driving circuit according to any one of claims 2 to 4, wherein the control module (11) comprises n voltage dividing resistors (RA 1 to RAn) and n voltage dividing comparators (P11 to P1 n), the n voltage dividing resistors are connected in series between the power source and the ground, the n voltage dividing resistors and the n voltage dividing comparators are in one-to-one correspondence, a first input terminal of each voltage dividing comparator inputs a predetermined reference Voltage (VREF), a second input terminal of each voltage dividing comparator is connected to the same side of the corresponding voltage dividing resistor, The n partial voltage comparators output the n sub-signals respectively.
  6. 6. The power tube driving circuit according to any one of claims 2-4, wherein the control module (11) comprises a first voltage dividing resistor (RB 1), a second voltage dividing resistor (RB 2), n common voltage comparators (P21-P2 n), the first voltage dividing resistor and the second voltage dividing resistor being connected in series between the power supply and the ground, a first input terminal of each common voltage comparator respectively inputting n different reference voltages (VREF 1-VREFn), a second input terminal of each common voltage comparator being connected between the first voltage dividing resistor and the second voltage dividing resistor, The n common voltage comparators output the n sub-signals respectively.
  7. 7. The power tube driving circuit according to any one of claims 2-4, wherein the control module (11) comprises a current source (I0), a preset switching tube (PM 0) and n signal generating sub-modules (111-11 n) outputting the n sub-signals respectively, each signal generating sub-module comprising a first switching tube (PMa), a second switching tube (PMb), a voltage drop generating module, a second preset Resistor (RC) and a capacitor (C0), The source electrode of the preset switch tube, the source electrode of the first switch tube and the source electrode of the second switch tube are connected with a power supply, the drain electrode and the grid electrode of the preset switch tube pass through the current source grounding wire, the grid electrode of the first switch tube is connected with the grid electrode of the preset switch tube, the drain electrode of the first switch tube is connected with the grid electrode of the second switch tube, the drain electrode of the first switch tube passes through the voltage drop generating module grounding wire, the drain electrode of the second switch tube is connected with one end of the second preset resistor and one end of the capacitor, the other end of the second preset resistor and the other end of the capacitor are connected with the grounding wire, and the drain electrode of the second switch tube outputs the sub signal.
  8. 8. The power tube driving circuit according to claim 7, wherein the voltage drop generating module comprises a third switching tube (NM 1) and a fourth switching tube (NM 2), a drain electrode of the third switching tube is connected to a drain electrode of the first switching tube, a diode connection is arranged between the third switching tube and the fourth switching tube, and a source electrode of the fourth switching tube is grounded.
  9. 9. The power transistor driving circuit according to claim 8, wherein the third switching transistor and the fourth switching transistor are MOS transistors or transistors.
  10. 10. The power tube driving circuit as claimed in claim 7, wherein the voltage drop generating module is a resistor or a diode.
  11. 11. A power tube driving method applied to the power tube driving circuit according to any one of claims 1 to 10, characterized in that the power tube driving circuit comprises an input module (10), an output module (20) and a transformer (30), the input module (10) and the output module (20) being connected through the transformer (30), the method comprising: The input module (10) controls the primary end of the transformer (30) to generate alternating current according to the acquired input signal, wherein a control signal is output according to the magnitude of the power supply voltage, and the magnitude of a current limiting resistance value in the input module (10) is regulated according to the control signal so that the current limiting resistance value increases along with the increase of the power supply voltage; The output module (20) receives a voltage signal of the secondary side of the transformer (30) and controls the power tube to be opened or closed according to the received voltage signal.

Description

Power tube driving circuit and power tube driving method Technical Field The present disclosure relates to the field of electronic circuits, and in particular, to a power tube driving circuit and a power tube driving method. Background In the ultra-high voltage power tube driving circuit, the problem that the power domains of the input end and the output end are different exists, the input ground is generally connected with the system ground and is 0V, the output ground is floating ground and is connected with the power tube (for example, the source electrode of the IGBT), and the minimum voltage is 0V, and the maximum voltage can be hundreds of volts or even thousands of volts. It is therefore necessary to isolate the input from the output, for example, by using a transformer. In high integration applications, the input chip, the output chip and the transformer used as isolation are packaged together, and in order to meet the requirement of small volume, the chip-level transformer used is realized by making a coupling coil on a silicon chip, and the inductance of the transformer is very small, generally only on the order of tens of nano-meters. In order to achieve a signal transmission between the input and output stages, an alternating current signal is usually generated at the windings of the transmitting end of the transformer, by means of which signal coupling between the windings it is ensured that the receiving end receives the corresponding signal and processes and responds. To ensure that the secondary chip is able to correctly receive and identify the corresponding signal, the current supplied to the transformer needs to be large enough, and if the current is small, the resonant amplitude on the transformer will decrease, the secondary chip may not be able to identify the corresponding signal. Disclosure of Invention An object of the present disclosure is to provide a power tube driving circuit and a power tube driving method that are reliable and consume less power. In order to achieve the above purpose, the present disclosure provides a power tube driving circuit, which includes an input module, an output module and a transformer, wherein the input module and the output module are connected through the transformer, the input module is used for controlling a primary end of the transformer to generate alternating current according to an obtained input signal, and the output module is used for receiving a voltage signal of a secondary end of the transformer and controlling opening and closing of a power tube according to the received voltage signal. Wherein the input module comprises: the control module is used for outputting a control signal according to the magnitude of the power supply voltage; And the current limiting resistance module is used for adjusting the magnitude of the current limiting resistance value in the input module according to the control signal so that the current limiting resistance value is increased along with the increase of the power supply voltage. Optionally, the current limiting resistor module includes a first preset resistor, n parallel resistors and n parallel switching tubes, the n parallel resistors and the n parallel switching tubes are in one-to-one correspondence, each parallel resistor and the corresponding parallel switching tube are connected in series and then connected in parallel with the first preset resistor, and the parallel resistor is the current limiting resistor in the input module. The control signals comprise n sub-signals, the n sub-signals are received by the n parallel switching tubes in a one-to-one correspondence mode, and each parallel switching tube is used for controlling on-off of a source electrode and a drain electrode according to the sub-signals received by the grid electrode. Optionally, the current limiting resistor module includes a first preset resistor, n series resistors and n series switching tubes, the n series resistors and the n series switching tubes are in one-to-one correspondence, each series resistor is connected in parallel with the corresponding series switching tube, the first preset resistor and the n series resistors are connected in series, and the resistors after being connected in series are current limiting resistors in the input module. The control signals comprise n sub-signals, the n sub-signals are received by the n series switching tubes in a one-to-one correspondence mode, and each series switching tube is used for controlling on-off of a source electrode and a drain electrode according to the sub-signals received by the grid electrode. Optionally, the current limiting resistor module includes a parallel portion and a serial portion, the parallel portion includes a first preset resistor, m mixed parallel resistors and m mixed parallel switching tubes, the m mixed parallel resistors and the m mixed parallel switching tubes are in one-to-one correspondence, and each mixed parallel resistor and the correspo