SG6902

The highly integrated SG6902 is designed for power supplies with boost PFC and flyback PWM. It requires few external components to achieve green mode operation and versatile protections. It is available in a 20-pin SOIC package.

The SG6902 feature synchronizes the PFC and PWM stages and reduces switching noise. At light loads, the switching frequency is continuously decreased to reduce power consumption. If output loading is further reduced, the PFC stage is turned off to reduce power consumption.

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 SG6902 shuts off PFC to prevent extra-high voltage on output. Programmable two-level output voltage control reduces the PFC output voltage at low line input to increase the efficiency of the power supply.

For the flyback PWM, the SG6902 ensures the stability of the current loop under continuous-conduction-mode operation. Built-in line-voltage compensation maintains a constant output power limit. Hiccup operation during output overloading is also guaranteed.

In addition, SG6902 provides protection functions, such as brownout and RI pin open/short protections.