US 9,812,856 B2
Modulation mode control circuit, switch control circuit including the modulation mode control circuit and power supply device including the switch control circuit
Won-Tae Lee, Cheonan-si (KR); Ji-Hoon Jang, Incheon (KR); and Hyeong Seok Baek, Bucheon-si (KR)
Assigned to Fairchild Korea Semiconductor Ltd., Bucheon (KR)
Filed by FAIRCHILD KOREA SEMICONDUCTOR LTD., Bucheon-si (KR)
Filed on Dec. 10, 2015, as Appl. No. 14/965,238.
Claims priority of provisional application 62/090,004, filed on Dec. 10, 2014.
Prior Publication US 2016/0172958 A1, Jun. 16, 2016
Int. Cl. H02H 3/247 (2006.01); H02M 3/335 (2006.01); H02M 1/00 (2006.01); H02M 1/32 (2007.01); H02M 1/36 (2007.01)
CPC H02H 3/247 (2013.01) [H02M 1/00 (2013.01); H02M 1/32 (2013.01); H02M 3/33592 (2013.01); H02M 1/36 (2013.01); H02M 2001/0003 (2013.01); Y02B 70/1433 (2013.01); Y02B 70/1475 (2013.01); Y02P 80/112 (2015.11)] 20 Claims
OG exemplary drawing
 
20. A power supply device, comprising:
at least one power switch connected to a winding on a primary side;
at least one synchronization rectification switch configured to generate an output voltage by synchronizing and rectifying a current flowing through a winding on a secondary side; and
a switch control circuit configured to select a modulation mode based on a result of a comparison between a control voltage based on the output voltage and a PWM threshold voltage determined by a resistor, generate a PWM reference voltage using the PWM threshold voltage and the control voltage, generate a first control signal based on a result of a comparison between an oscillation control signal and the control voltage and a result of a comparison between a first signal and the PWM threshold voltage, generate a second control signal based on a result of a comparison between the first signal and the PWM reference voltage, and generate at least one clock signal for controlling the at least one power switch using at least one of the first control signal and the second control signal based on the selected modulation mode.