US 11,703,550 B2
Resonance voltage attenuation detection circuit, semiconductor device for switching power, and switching power supply
Satoshi Arima, Isehara (JP); and Hiroki Matsuda, Zama (JP)
Assigned to MITSUMI ELECTRIC CO., LTD., Tokyo (JP)
Filed by Satoshi Arima, Isehara (JP); and Hiroki Matsuda, Zama (JP)
Filed on Dec. 10, 2020, as Appl. No. 17/117,243.
Claims priority of application No. 2019-235114 (JP), filed on Dec. 25, 2019.
Prior Publication US 2021/0199728 A1, Jul. 1, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G01R 31/62 (2020.01); G01R 19/165 (2006.01); G01R 31/14 (2006.01); G01R 1/20 (2006.01)
CPC G01R 31/62 (2020.01) [G01R 1/20 (2013.01); G01R 19/16566 (2013.01); G01R 31/14 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A resonance voltage attenuation detection circuit that detects attenuation of a resonance voltage of a winding of a transformer, the resonance voltage attenuation detection circuit comprising:
a first voltage comparator circuit that compares a voltage of the winding with a predetermined first voltage; and
a time-out circuit that performs clocking operation in accordance with an output of the first voltage comparator circuit,
wherein the time-out circuit outputs an attenuation detection signal when the time-out circuit has clocked a preset period which is shorter than a time required for a peak voltage of the winding to be attenuated from the first voltage to a predetermined second voltage lower than the first voltage.