Richtek Technology Corporation

Shih-Ho Hsu

Wei-Hsu Chang

Ta-Yung Yang

Mao-Hui Kuo

Kun-Yu Lin

A power factor correction control circuit for correcting a power factor of a rectified power to generate an output power supplied to a load, includes: a reference voltage generator circuit generating a reference voltage according to a rectified voltage of the rectified power; and a feedback modulation circuit generating a modulation control signal based upon the reference voltage and a feedback signal related to an output voltage of the output power, to control at least one switch of a power stage circuit to switch an inductor in the power stage circuit and to thereby regulate the output voltage. The reference voltage generator circuit selects one of at least two candidate voltages as the reference voltage according to a comparison result between the rectified voltage and at least one threshold, such that the output voltage is at least partially positively correlated with the rectified voltage.

Power supply system and power factor correction control circuit and control method thereof

A boost power factor correction circuit includes: a switch and an inductor coupled to each other; a current sensing device generating a current sensing signal according to a current flowing through the switch; a temperature sensing device coupled to the inductor to generate a temperature sensing signal; and a conversion control circuit operating the switch. The conversion control circuit is an integrated circuit and includes: a shared pin coupled to the temperature sensing device and the current sensing device; and a current sensing circuit and a temperature sensing circuit which sense a multipurpose sensing signal through the shared pin. The multipurpose sensing signal is related to the current sensing signal when the switch is ON and related to the temperature sensing signal when the switch is OFF. The temperature sensing signal is related to an input voltage, an output voltage and an electrical parameter of the temperature sensing device.

High efficiency boost power factor correction circuit having shared pin and conversion control circuit thereof

A power supply system includes a power factor correction converter circuit and an isolated power converter circuit, wherein the power factor correction converter circuit corrects the power factor of a rectified power to generate a first output power, and the isolated power converter circuit converts the first output power to generate a second output power. The isolated power converter circuit includes a transformer, and the transformer includes a primary winding, a secondary winding, and an auxiliary winding. The auxiliary winding generates an auxiliary voltage which is related to the second output power. When the auxiliary voltage is lower than a disabled threshold, indicating that the voltage of the second output power is lower than a threshold, the power factor correction converter circuit provides a bypassing connection from the rectified power to the first output power and stops correcting the power factor of the rectified power.

Growing community of inventors

Taipei, Taiwan

Shih-Ho Hsu