US 9,812,978 B2
Circuit and method for driving synchronous rectifiers for high-frequency flyback converters
Xiucheng Huang, Blacksburg, VA (US); Fred C. Lee, Blacksburg, VA (US); and Qiang Li, Blacksburg, VA (US)
Assigned to Virginia Tech Intellectual Properties, Inc., Blacksburg, VA (US)
Filed by Virginia Tech Intellectual Properties, Inc., Blacksburg, VA (US)
Filed on Mar. 30, 2016, as Appl. No. 15/85,012.
Claims priority of provisional application 62/142,078, filed on Apr. 2, 2015.
Prior Publication US 2016/0294292 A1, Oct. 6, 2016
Int. Cl. H02M 3/335 (2006.01); H02M 1/44 (2007.01); H02M 1/08 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/33592 (2013.01) [H02M 1/08 (2013.01); H02M 1/44 (2013.01); H02M 2001/0048 (2013.01); Y02B 70/1475 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A transformer isolated power converter comprising
a transformer,
a synchronous rectifier connected in series with a secondary winding of said transformer,
a series connected resistance and capacitance connected in parallel with said synchronous rectifier, and
a circuit responsive to a voltage developed across said capacitor for developing a signal to control said synchronous rectifier wherein a waveform of said voltage developed across said capacitor is substantially identical in shape and phase and of a same or different amplitude as a magnetizing inductance current waveform of said transformer.