FP6277 Function Description Operation The FP6277 is a current mode synchronous boost converter. The constant switching frequency is 500 kHz and operates with pulse width modulation (PWM). Build-in 30mΩ high side switch and 30mΩ low side switch provides a high efficient conversion. Soft Start Function Soft start circuitry is integrated into FP6277 to avoid inrush current during power on. After the IC is enabled, the output of error amplifier is clamped by the internal soft-start function, which causes PWM pulse width increasing slowly and thus reducing input surge current. Current Limit Program A resistor between OC and GND pin programs peak switch current. The resistor value should be between 26.5k and 300k. The current limit can be set from 7A to 0.8A. The OC pin can’t float must connect a resistor to ground. Keep traces at this pin as short as possible. Do not put capacitance at this pin. Set the over current trip point according to the following equation: IOCP 180000 0.2 R3 Over Temperature Protection (OTP) FP6277 will turn off the power MOSFET automatically when the internal junction temperature is higher than 150°C. The power MOSFET wake up when the junction temperature drops 30 °C under the OTP threshold temperature. This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product. Website: http://www.feeling-tech.com.tw Rev. 0.65 8/12