Title :
A constant power limit feedforward control circuit for flyback converters
Author :
Choi, Jin-ho ; Liu, Jin ; Lee, Hoi
Author_Institution :
Fairchild Semicond., Dallas, TX
Abstract :
A new feedforward pulse width modulator (FF-PWM) control circuit for AC-DC flyback converters is proposed in this paper. By using the proposed circuit, the DC converter input voltage with the AC line voltage is proportional to the reference voltage. In addition, the proposed FF-PWM can be easily implemented on chip by using a transconductance amplifier, Wilson current source and current mirror. Simulation and experimental results show that the maximum power change ratio of the flyback converter adopting the proposed feedforward PWM modulator is within 20% at the universal input voltage ranging from 85VAC to 265VAC
Keywords :
AC-DC power convertors; PWM power convertors; current mirrors; feedforward; power amplifiers; 85 to 265 V; AC-DC flyback converters; Wilson current mirror; Wilson current source; feedforward control circuit; feedforward pulse width modulator; transconductance amplifier; Analog-digital conversion; Circuit faults; Circuit simulation; DC-DC power converters; Feedforward systems; Pulse amplifiers; Pulse width modulation; Pulse width modulation converters; Switching converters; Voltage control;
Conference_Titel :
Applied Power Electronics Conference and Exposition, 2006. APEC '06. Twenty-First Annual IEEE
Conference_Location :
Dallas, TX
Print_ISBN :
0-7803-9547-6
DOI :
10.1109/APEC.2006.1620710
