SG6932

SG6932 — PFC / Forward PWM Controller www.DataSheet4U.com May 2008 SG6932 PFC / Forward PWM Controller Features ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ Interleaved PFC/PWM Switching Low Operating Current Innovative Switching-Charge Multiplier-divider Multi-vector Control for Improved PFC Output Transient Response Average Current Mode for Input-current Shaping PFC Over-voltage and Under-voltage Protections PFC and PWM Feedback Open-loop Protection Cycle-by-cycle Current Limiting for PFC/PWM Slope Compensation for PWM Selectable PWM Maximum Duty Cycle: 50%, 65% Brownout Protection Power-on Sequence Control and Soft-start Description The highly integrated SG6932 is designed for power supplies with boost PFC and forward PWM. It requires very few external components to achieve versatile protections and compensation. It is available in 16-pin DIP and SOP packages. The proprietary interleave-switching feature synchronizes the PFC and PWM stages and reduces switching noise. At light load, the switching frequency is continuously decreased to reduce power consumption. For PFC stage, the proprietary multi-vector control scheme provides a fast transient response in a lowbandwidth PFC loop; in which the overshoot and undershoot of the PFC voltage are clamped. If the feedback loop is broken, SG6932 shuts off to prevent extra-high voltage on output. For the forward PWM stage, the synchronized slope compensation ensures the stability of the current loop under continuous-conduction-mode (CCM) operation. ...