CN-112468128-B - Driving circuit and semiconductor device

Abstract

The invention provides a driving circuit and a semiconductor device. It is desirable to protect the driving circuit even if the potential applied to the low potential terminal fluctuates. A driving circuit is provided which controls an output section which switches whether or not to supply a current to an output line according to a potential difference between a1 st control signal inputted and a voltage of the output line, wherein the driving circuit includes a control line which transmits the 1 st control signal to the output section, a low potential line to which a predetermined reference potential is applied, a1 st connection switching section which switches whether or not to connect the control line and the low potential line according to a2 nd control signal, and a cutting section which is provided in series with the 1 st connection switching section between the control line and the low potential line, and cuts off the control line and the low potential line based on the potential of the low potential line.

Inventors

• NAKAGAWA SHO
• MORIO IWAMIZU

Assignees

• 富士电机株式会社

Dates

Publication Date

20260508

Application Date

20200729

Priority Date

20190906

Claims (11)

1. 1. A driving circuit that controls an output section that switches whether or not to supply current to an output line according to a potential difference between an input 1 st control signal and a voltage of the output line, comprising: a control line that transmits the 1 st control signal to the output section; a low potential line to which a predetermined reference potential is applied; a high potential line to which a high potential higher than the 1 st threshold potential is applied; a pre-stage control unit provided between the high potential line and the low potential line, and configured to output a potential of one of the high potential line and the low potential line as a2 nd control signal; A1 st connection switching unit having one end connected to the control line and switching whether to connect the control line and the low potential line according to the 2 nd control signal, and A cutting section provided in series with the 1 st connection switching section between the control line and the low potential line, for cutting the control line and the low potential line based on a potential of the low potential line, The 1 st connection switching section has a MOSFET which is turned on when the potential inputted from the preceding control section is higher than the 2 nd threshold potential, The cutoff portion is connected to the other end of the 1 st connection switching portion such that the 1 st connection switching portion and the cutoff portion are electrically connected in series with the control line and the low potential line, and cuts off the connection between the control line and the low potential line based on the potential of the low potential line.
2. 2. The driving circuit according to claim 1, wherein, The cutting unit cuts the control line and the low potential line regardless of the value of the 2 nd control signal when the potential of the low potential line is higher than the 1 st threshold potential.
3. 3. The driving circuit according to claim 1, wherein, The front-stage control unit includes: a1 st inverter provided between the high potential line and the low potential line, the 1 st inverter selecting and outputting a potential of either the high potential line or the low potential line according to an input signal, and A2 nd inverter provided between the high potential line and the low potential line, the 2 nd inverter selecting a potential of one of the high potential line and the low potential line according to an output of the 1 st inverter, and inputting the potential of one of the high potential line and the low potential line as the 2 nd control signal to a MOSFET of the 1 st connection switching section, The cutting unit cuts the control line and the low potential line when the output of the 1 st inverter is higher than the 1 st threshold potential.
4. 4. The driving circuit according to claim 1, wherein, The front-stage control unit includes: A1 st inverter provided between the high potential line and the low potential line, the 1 st inverter selecting and outputting a potential of one of the high potential line and the low potential line according to an input signal; A 2 nd inverter provided between the high potential line and the low potential line, the 2 nd inverter selecting a potential of one of the high potential line and the low potential line based on an output of the 1 st inverter and inputting the potential of one of the high potential line and the low potential line as the 2 nd control signal to the MOSFET of the 1 st connection switching portion, and A 3 rd inverter provided between the high potential line and the low potential line, the 3 rd inverter selecting a potential of one of the high potential line and the low potential line according to an output of the 2 nd inverter and inputting the potential of one of the high potential line and the low potential line to the cutting portion, The cutting unit cuts the control line and the low potential line when the output of the 3 rd inverter is higher than the 1 st threshold potential.
5. 5. The driving circuit according to claim 1, wherein, The front-stage control unit includes: A1 st inverter provided between the high potential line and the low potential line, the 1 st inverter selecting and outputting a potential of one of the high potential line and the low potential line according to an input signal; A 2 nd inverter provided between the high potential line and the low potential line, the 2 nd inverter selecting a potential of one of the high potential line and the low potential line based on an output of the 1 st inverter and inputting the potential of one of the high potential line and the low potential line as the 2 nd control signal to the MOSFET of the 1 st connection switching portion, and A 3 rd inverter provided between the high potential line and the low potential line, the 3 rd inverter selecting a potential of one of the high potential line and the low potential line according to an input to the 1 st inverter and inputting the potential of one of the high potential line and the low potential line to the cutting portion, The cutting unit cuts the control line and the low potential line when the output of the 3 rd inverter is higher than the 1 st threshold potential.
6. 6. The drive circuit of claim 1, further comprising: A 2 nd connection switching unit for switching whether or not the control line and the output line are connected, and And a subsequent control unit that connects the control line and the output line to the 2 nd connection switching unit when the preceding control unit outputs a voltage higher than a predetermined 3 rd threshold potential.
7. 7. The driving circuit according to claim 6, wherein, The rear-stage control unit is provided between the high-potential line and the output line, selects a potential of either the high-potential line or the output line according to a voltage output from the front-stage control unit, and inputs the potential of either the high-potential line or the output line to the 2 nd connection switching unit.
8. 8. A driving circuit according to claim 6 or 7, wherein, The front-stage control unit includes: A1 st inverter provided between the high potential line and the low potential line, the 1 st inverter selecting and outputting a potential of one of the high potential line and the low potential line according to an input signal; A2 nd inverter provided between the high potential line and the low potential line, the 2 nd inverter selecting a potential of one of the high potential line and the low potential line according to an output of the 1 st inverter, and inputting the potential of one of the high potential line and the low potential line as the 2 nd control signal to a MOSFET of the 1 st connection switching unit; A 3 rd inverter provided between the high potential line and the low potential line, the 3 rd inverter selecting a potential of one of the high potential line and the low potential line based on an output of the 2 nd inverter and inputting the potential of one of the high potential line and the low potential line to the cutting portion, and A 4 th inverter provided between the high potential line and the low potential line, the 4 th inverter selecting a potential of one of the high potential line and the low potential line according to an output of the 1 st inverter and inputting the potential of one of the high potential line and the low potential line to the rear-stage control unit, The cutting unit cuts the control line and the low potential line when the output of the 3 rd inverter is higher than the 1 st threshold potential.
9. 9. A driving circuit according to claim 6 or 7, wherein, The front-stage control unit includes: A1 st inverter provided between the high potential line and the low potential line, the 1 st inverter selecting and outputting a potential of one of the high potential line and the low potential line according to an input signal; A2 nd inverter provided between the high potential line and the low potential line, the 2 nd inverter selecting a potential of one of the high potential line and the low potential line based on an output of the 1 st inverter and inputting the potential of one of the high potential line and the low potential line to the MOSFET of the 1 st connection switching unit and the rear control unit, and A 3 rd inverter provided between the high potential line and the low potential line, the 3 rd inverter selecting a potential of one of the high potential line and the low potential line according to an output of the 2 nd inverter and inputting the potential of one of the high potential line and the low potential line to the cutting portion, The cutting unit cuts the control line and the low potential line when the output of the 3 rd inverter is higher than the 1 st threshold potential.
10. 10. A driving circuit according to any one of claims 1 to 7, wherein, The 1 st connection switching section has an n-channel MOSFET arranged between the control line and the low potential line, The cut-off portion has a p-channel MOSFET disposed between the n-channel MOSFET and the low potential line.
11. 11. A semiconductor device, comprising: an output line; an output section for switching whether or not to supply current to the output line based on a potential difference between an input 1 st control signal and a voltage of the output line, and The drive circuit of any one of claims 1 to 10.

Description

Driving circuit and semiconductor device Technical Field The present invention relates to a driving circuit and a semiconductor device. Background Conventionally, a drive circuit for driving a power semiconductor such as a MOSFET or an IGBT (insulated gate bipolar transistor) is known (for example, refer to patent documents 1 and 2). The driving circuit has a low potential terminal connected to a low potential such as a ground potential. Patent document 1 Japanese patent laid-open No. 2009-10477 Patent document 2 Japanese patent laid-open No. 8-83909 Disclosure of Invention Technical problem to be solved by the invention It is desirable to protect the driving circuit even if the potential applied to the low potential terminal fluctuates. Technical proposal for solving the technical problems In order to solve the above-described problem, in the 1 st aspect of the present invention, there is provided a drive circuit which controls an output section which switches whether or not to supply a current to an output line according to a potential difference between an input 1 st control signal and a voltage of the output line. The driving circuit may include a control line transmitting the 1 st control signal to the output part. The driving circuit may include a low potential line to which a predetermined reference potential is applied. The driving circuit may include a1 st connection switching section that switches whether to connect the control line and the low potential line according to a 2 nd control signal. The driving circuit may include a cutoff portion provided in series with the 1 st connection switching portion between the control line and the low potential line, the cutoff portion cutting the control line and the low potential line based on the potential of the low potential line. The cutting unit may cut the control line and the low potential line regardless of the value of the 2 nd control signal when the potential of the low potential line is higher than the 1 st threshold potential. The driving circuit may include a high potential line to which a high potential higher than the 1 st threshold potential is applied. The drive circuit may include a pre-stage control section provided between the high potential line and the low potential line, and the drive circuit may input a potential of one of the high potential line and the low potential line as the 2 nd control signal to the 1 st connection switching section. The 1 st connection switching unit may have a MOSFET that is turned on when the potential input from the previous control unit is higher than the 2 nd threshold potential. The front-stage control unit may have a1 st inverter provided between the high potential line and the low potential line, and may select and output a potential of one of the high potential line and the low potential line in accordance with an input signal. The front-stage control unit may have a2 nd inverter provided between the high potential line and the low potential line, selects a potential of one of the high potential line and the low potential line according to an output of the 1 st inverter, and inputs the potential of one of the high potential line and the low potential line as the 2 nd control signal to the MOSFET of the 1 st connection switching unit. The cutting unit may cut the control line and the low potential line when the 1 st inverter output is higher than the 1 st threshold potential. The front-stage control unit may have a1 st inverter provided between the high potential line and the low potential line, and may select and output a potential of one of the high potential line and the low potential line in accordance with an input signal. The front-stage control unit may have a2 nd inverter provided between the high potential line and the low potential line, selects a potential of one of the high potential line and the low potential line according to an output of the 1 st inverter, and inputs the potential of one of the high potential line and the low potential line as the 2 nd control signal to the MOSFET of the 1 st connection switching unit. The front-stage control unit may have a 3 rd inverter provided between the high potential line and the low potential line, and may select a potential of one of the high potential line and the low potential line based on an output of the 2 nd inverter, and may input the potential of one of the high potential line and the low potential line to the cutting unit. The cutting unit may cut the control line and the low potential line when the output of the 3 rd inverter is higher than the 1 st threshold potential. The front-stage control unit may have a1 st inverter provided between the high potential line and the low potential line, and may select and output a potential of one of the high potential line and the low potential line in accordance with an input signal. The front-stage control unit may have a2 nd inverter provided between the high potential line and the low potenti