FAN400C

This highly integrated PWM controller provides several features to enhance the performance of low-power flyback converters. To minimize standby power consumption, a proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency under light-load and zero-load conditions. This green mode enables the power supply to meet international power conservation requirements. Another advantage of the FAN400A is that the typical startup current is only 8?A, while the typical operating current can be as low as 3.6mA. A large startup resistance can be used to achieve even higher power conversion efficiency.

FAN400C integrates a frequency-hopping function internally to reduce EMI emissions with minimum line filters. Built-in synchronized slope compensation maintains the stability of peak current-mode control. Proprietary internal compensation ensures constant output power limiting over a universal range of AC input voltages, from 90V_AC to 264V_AC.

The FAN400C provides many protection functions. Pulse-by-pulse current limiting ensures constant output current, even if a short circuit occurs. The internal protection circuit disables PWM output if V_DD exceeds 24.5V. The gate output is clamped at 17V to protect the power MOS from over-voltage damage. The built-in over-temperature protection (OTP) function shuts down the controller at 140?C with a 30?C hysteresis.

The FAN400C is designed to provide a low-cost total solution for flyback converters. It is available in a small-footprint, 6-pin, SSOT-6 package.