US 11,892,481 B2
Current detecting circuit and switching circuit
Yoichi Takano, Tokyo (JP); and Kohei Sakurai, Tokyo (JP)
Assigned to MITSUMI ELECTRIC CO., LTD., Tokyo (JP)
Filed by Yoichi Takano, Tokyo (JP); and Kohei Sakurai, Tokyo (JP)
Filed on Aug. 31, 2021, as Appl. No. 17/446,480.
Claims priority of application No. 2020-151117 (JP), filed on Sep. 9, 2020.
Prior Publication US 2022/0074973 A1, Mar. 10, 2022
Int. Cl. G01R 19/00 (2006.01); H03K 17/16 (2006.01); G01R 19/10 (2006.01)
CPC G01R 19/0092 (2013.01) [H03K 17/163 (2013.01); H03K 17/166 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A current detecting circuit comprising:
a power supply terminal;
an output terminal;
a first switching circuit of which an input side is electrically coupled to the power supply terminal, the first switching circuit including a first control terminal;
a second switching circuit of which an input side is electrically coupled to the power supply terminal, the second switching circuit including a second control terminal electrically coupled to the first control terminal of the first switching circuit;
a third switching circuit electrically coupled in series with the first switching circuit, an output side of the third switching circuit being electrically coupled to the output terminal;
a first anti-backflow circuit electrically coupled in antiparallel with the first switching circuit to prevent backflow from the output terminal into the power supply terminal;
a second anti-backflow circuit electrically coupled in antiparallel with the second switching circuit to prevent backflow into the power supply terminal; and
a current amplifier configured to detect a difference between a first output voltage of the first switching circuit and a second output voltage of the second switching circuit, and to output a relative current to be used for detecting an output current that flows out from the output terminal,
wherein a ratio of resistance associated with the first switching circuit to resistance associated with the second switching circuit is n:1, where n is an integer greater than one.