US 12,294,287 B2
Semiconductor switching element drive circuit and semiconductor device
Kazuaki Hiyama, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/756,404
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Feb. 10, 2020, PCT No. PCT/JP2020/005054
§ 371(c)(1), (2) Date May 24, 2022,
PCT Pub. No. WO2021/161362, PCT Pub. Date Aug. 19, 2021.
Prior Publication US 2023/0006552 A1, Jan. 5, 2023
Int. Cl. H02M 1/08 (2006.01); H02M 1/00 (2007.01); H02M 3/157 (2006.01); H10D 62/832 (2025.01)
CPC H02M 1/08 (2013.01) [H02M 1/0029 (2021.05); H02M 3/157 (2013.01); H10D 62/8325 (2025.01)] 11 Claims
OG exemplary drawing
 
1. A semiconductor switching element drive circuit configured to drive a semiconductor switching element, the semiconductor switching element drive circuit comprising:
a voltage-dividing resistor configured to generate a divided voltage of an output voltage of the semiconductor switching element;
a logic circuit configured to invert a level of an output signal based on the divided voltage;
a switching circuit configured to switch a gate drive condition of the semiconductor switching element during a turn-off operation from a first gate drive condition in which a switching speed of the semiconductor switching element is a first switching speed to a second gate drive condition in which the switching speed is a second switching speed lower than the first switching speed based on the output signal from the logic circuit; and
a cutoff circuit configured to cut off an input of the divided voltage to the logic circuit except for a period from when a turn-off operation of the semiconductor switching element is started until a gate drive condition of the semiconductor switching element is switched from the first gate drive condition to the second gate drive condition,
wherein a comparator is not connected between the divided voltage and an input of the switching circuit.