FAN6300H

Highly Integrated Quasi-Resonant Current Mode PWM Controller FAN6300A / FAN6300H The highly integrated FAN6300A/H of PWM controller provides several features to enhance the performance of flyback converters. FAN6300A is applied on quasiresonant flyback converters where maximum operating frequency is below 100 kHz. FAN6300H is suitable for high−frequency operation (up to 190 kHz). 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. The operating frequency is limited by minimum tOFF time, which is 38 ms to 8 ms in FAN6300A and 13 ms to 3 ms in FAN6300H, so FAN6300H can operate at higher switching frequency than FAN6300A. FAN6300A/H controller also provides many protection functions. Pulse−by−pulse current limiting ensures the fixed−peak current limit level, even when a short circuit occurs. Once an open−ci...