The FAN6300HMY is a highly integrated quasi-resonant current-mode PWM Controller provides several features to enhance the performance of flyback converters. It is suitable for high-frequency operation (up to 190kHz). A built-in HV startup circuit can provide more startup current to reduce the startup time of the controller. Once the VDD voltage exceeds the turn-on threshold voltage, the HV startup function is disabled immediately to reduce power consumption. An internal valley voltage detector ensures power system operates at quasi-resonant operation over a wide-range of line voltage and any load conditions, as well as reducing switching loss to minimize switching voltage on drain of power MOSFET. To minimize standby power consumption and light-load efficiency, a proprietary green-mode function provides off-time modulation to decrease switching frequency and perform extended valley voltage switching to keep to a minimum switching voltage.