US 11,984,811 B2
Power supply control device and switching power supply apparatus
Shinichiro Watanabe, Chino (JP); Katsumi Inoue, Matsumoto (JP); and Kanji Aoki, Suwa (JP)
Assigned to SEIKO EPSON CORPORATION, Tokyo (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Mar. 24, 2022, as Appl. No. 17/703,202.
Claims priority of application No. 2021-054247 (JP), filed on Mar. 26, 2021.
Prior Publication US 2022/0311346 A1, Sep. 29, 2022
Int. Cl. H02M 3/335 (2006.01); H02M 1/00 (2006.01); H02M 1/32 (2007.01)
CPC H02M 3/33569 (2013.01) [H02M 1/0006 (2021.05); H02M 1/0032 (2021.05); H02M 1/32 (2013.01); H02M 3/33523 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A power supply control device that controls a switching element of a switching power supply apparatus which includes
a transformer having a primary winding, a secondary winding, and an auxiliary winding,
the switching element coupled to the primary winding, and
a capacitor coupled to the auxiliary winding, the power supply control device comprising:
a power supply terminal coupled to one end of the capacitor;
a switch and a resistor coupled in series between the power supply terminal and a ground;
a first control circuit that controls the switch; and
a second control circuit that controls the switching element,
wherein
the first control circuit performs control to turn on the switch when a first voltage applied to the power supply terminal continuously exceeds a first reference voltage for a first time,
the second control circuit performs control to turn off the switching element when the first voltage exceeds a second reference voltage higher than the first reference voltage,
the second control circuit performs control to turn off the switching element when the first voltage continuously exceeds the second reference voltage for a second time, and
the first time is longer than the second time.