US 12,191,845 B2
Load drive device
Keishi Komoriyama, Hitachinaka (JP); and Yoichiro Kobayashi, Hitachinaka (JP)
Assigned to HITACHI ASTEMO, LTD., Hitachinaka (JP)
Appl. No. 17/786,009
Filed by Hitachi Astemo, Ltd., Hitachinaka (JP)
PCT Filed Dec. 11, 2020, PCT No. PCT/JP2020/046238
§ 371(c)(1), (2) Date Jun. 16, 2022,
PCT Pub. No. WO2021/131778, PCT Pub. Date Jul. 1, 2021.
Claims priority of application No. 2019-237205 (JP), filed on Dec. 26, 2019.
Prior Publication US 2023/0016629 A1, Jan. 19, 2023
Int. Cl. H03K 17/082 (2006.01); H02H 1/00 (2006.01); H03F 3/45 (2006.01)
CPC H03K 17/0822 (2013.01) [H03F 3/45475 (2013.01); H02H 1/0007 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A load drive device comprising:
a first transistor connected between a first control electrode and an inductive load;
an active clamp circuit that becomes conductive when a terminal voltage of a second control electrode between the first transistor and the inductive load exceeds a threshold;
a second transistor connected to the second control electrode and connected in parallel to the first transistor;
a buffer circuit that is connected to the first transistor via the first control electrode, receives an input of an input signal for driving the inductive load, and drives the first transistor;
a resistor connected in series to the second transistor, and
a voltage amplifier circuit that compares a voltage of the second control electrode with a predetermined voltage threshold,
wherein the voltage amplifier circuit outputs a voltage level obtained by amplifying a differential voltage between the voltage of the second control electrode and the voltage threshold, and
conduction of the second transistor is controlled by the amplified voltage level.