The highly integrated SG6901A is designed for power supplies with boost PFC and flyback PWM. It requires very few external components to achieve versatile protections. It is available in a 20-pin SOP package.

A proprietary interleave-switching feature synchronizes the PFC and PWM stages and reduces switching noise.

For PFC stage, the proprietary multi-vector control scheme provides a fast transient response in a low-bandwidth PFC loop, in which the overshoot and undershoot of the PFC voltage are clamped. If the feedback loop is broken, the SG6901A shuts off PFC to prevent extra-high voltage on output.

For the flyback PWM, the synchronized slope compensation ensures the stability of the current loop under continuous-conduction-mode operation. Built-in line-voltage compensation maintains constant output-power limit. Hiccup operation during output overloading is also guaranteed.

In addition, SG6901A provides protection functions, such as brownout and RI pin open/short protection.

• Interleaved PFC/PWM Switching
• Low Startup and Operating Current
• Innovative Switching Charge Multiplier Divider
• Multi-vector Control for Improved PFC Output Transient Response
• Average-Current-Mode Control for PFC
• Programmable Two-Level PFC Output Voltage Protections
• PFC and PWM Feedback Open-Loop Protection
• Cycle-by-Cycle Current Limiting for PFC/PWM
• Slope Compensation for PWM
• H/L Line Over-Power Compensation for PWM
• Brownout Protection
• Over-Temperature Protection (OTP)
• Over-temperature protection (OTP)

• Switching Power Supplies with Active PFC and Standby Power
• High-Power Adaptors