Semiconductor device, inverter, and automobile

Patent metadata

Field	Value
Publication number	US-10833669-B2
Application number	US-201616461664-A
Country	US
Kind code	B2
Filing date	Dec 22, 2016
Priority date	Dec 22, 2016
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

The present invention relates to a semiconductor device provided with a dead-time generation circuit, the semiconductor device including: first and second status-detection circuits that each have a function of detecting whether first and second switching devices are in turn-off operation to output first and second status signals, respectively, and each have a function of generating a dead time of on-off operation of the corresponding one of the first and second switching devices; a first logic circuit that receives a first on-off command signal instructing the first switching device to be turned on or off, and the second status signal to output a signal allowing the first switching device to be turned on only when the second switching device is not in turn-off operation; and a second logic circuit that receives the first on-off command signal instructing the second switching device to be turned on or off, and the first status signal to output a signal allowing the second switching device to be turned on only when the first switching device is not in turn-off operation.

First claim

The invention claimed is:

1. A semiconductor device comprising:
first and second switching devices connected in series between a first potential and a second potential lower than the first potential to operate complementarily;
a first gate driving circuit that performs driving control of the first switching device;
a second gate driving circuit that performs driving control of the second switching device;
a first status-detection circuit having functions of not only detecting whether the first switching device is in turn-off operation to output a result of the detection as a first status signal, but also generating a dead time of on-off operation of each of the first and second switching devices;
a second status-detection circuit having functions of not only detecting whether the second switching device is in turn-off operation to output a result of the detection as a second status signal, but also generating a dead time of on-off operation of each of the first and second switching devices;
first and second input terminals to which first and second on-off command signals for turning on and off the first and second switching devices are input, respectively;
a first logic circuit that receives the first on-off command signal and the second status signal, and that outputs the first on-off command signal as a signal for turning on the first switching device only when the second status signal indicates that the second switching device is not in turn-off operation;
a second logic circuit that receives the second on-off command signal and the first status signal, and that outputs the second on-off command signal as a signal for turning on the second switching device only when the first status signal indicates that the first switching device is not in turn-off operation;
a first protection circuit that detects an abnormality of the first switching device to output a first error signal indicating that the first switching device is abnormal;
a fifth logic circuit that synthesizes the first status signal and the first error signal to output the synthesized signal as the first status signal;
a second protection circuit that detects an abnormality of the second switching device to output a second error signal indicating that the second switching device is abnormal;
a sixth logic circuit that synthesizes the second status signal and the second error signal to output the synthesized signal as the second status signal;
a first filter circuit that separates the first error signal from the first status signal in which the first error signal is synthesized and outputs a first resultant signal; and
a second filter circuit that separates the second error signal from the second status signal in which the second error signal is synthesized and outputs a second resultant signal.

2. The semiconductor device according to claim 1 , wherein
the first status-detection circuit includes a first comparator that compares voltages at both ends of a first gate resistor connected to a gate of the first switching device, the first comparator outputting the first status signal indicating that the first switching device is in turn-off operation in a period in which the first gate resistor has a voltage drop, and
the second status-detection circuit includes a second comparator that compares voltages at both ends of a second gate resistor connected to a gate of the second switching device, the second comparator outputting the second status signal indicating that the second switching device is in turn-off operation in a period in which the second gate resistor has a voltage drop.

3. The semiconductor device according to claim 1 , wherein
the first protection circuit has a soft shut-off function of turning off the first switching device at a switching speed slower than that of turning off by the first gate driving circuit when an abnormality of the first switching device is detected, and
the second protection circuit has a soft shut-off function of turning off the second switching device at a switching speed slower than that of turning off by the second gate driving circuit when an abnormality of the second switching device is detected.

4. The semiconductor device according to claim 1 , wherein
the first status signal in which the first error signal is synthesized is input to the first filter circuit via a first insulating element, and
the second status signal in which the second error signal is synthesized is input to the second filter circuit via a second insulating element.

5. The semiconductor device according to claim 4 , wherein the first and second insulating elements are each composed of a magnetic coupler that performs isolation using magnetic coupling.

6. An inverter comprising the semiconductor device according to claim 1 .

7. An automobile that controls a running motor and an electric-power regenerative motor by using the inverter according to claim 6 .

8. A semiconductor device comprising:
first and second switching devices connected in series between a first potential and a second potential lower than the first potential to operate complementarily;
a first gate driving circuit that performs driving control of the first switching device;
a second gate driving circuit that performs driving control of the second switching device:
a first status-detection circuit having functions of not only detecting whether the first switching device is in turn-off operation to output a result of the detection as a first status signal, but also generating a dead time of on-off operation of each of the first and second switching devices;
a second status-detection circuit having functions of not only detecting whether the second switching device is in turn-off operation to output a result of the detection as a second status signal, but also generating a dead time of on-off operation of each of the first and second switching devices;
first and second input terminals to which first and second on-off command signals for turning on and off the first and second switching devices are input, respectively;
a first logic circuit that receives the first on-off command signal and the second status signal, and that outputs the first on-off command signal as a signal for turning on the first switching device only when the second status signal indicates that the second switching device is not in turn-off operation;
a second logic circuit that receives the second on-off command signal and the first status signal, and that outputs the second on-off command signal as a signal for turning on the second switching device only when the first status signal indicates that the first switching device is not in turn-off operation,
wherein
the first status-detection circuit includes
a first comparator that compares a gate voltage of the first switching device with a predetermined first reference voltage, and
a third logic circuit that receives a first inversion signal generated by inverting the first on-off command signal and an output signal of the first comparator, and that outputs the first status signal indicating that the first switching device is in turn-off operation in a period satisfying the following conditions: the first inversion signal is a signal for turning off the first switching device; and the first switching device has a gate voltage higher than the first reference voltage,

the second status-detection circuit includes
a second comparator that compares a gate voltage of the second switching device with a predetermined second reference voltage, and
a fourth logic circuit that receives a second inversion signal generated by inverting the second on-off command signal and an output signal of the second comparator, and that outputs the second status signal indicating that the second

Assignees

• Mitsubishi Electric Corp

Inventors

• Hiyama Kazuaki

Classifications

• H02P27/08

  with pulse width modulation · CPC title

• H03K17/08122 Primary

  in field-effect transistor switches · CPC title

• H02M1/38

  Means for preventing simultaneous conduction of switches · CPC title

• H02P29/027 Primary

  the fault being an over-current · CPC title

• H02M7/53871

  with automatic control of output voltage or current · CPC title