The IC is specially designed for switching power supply system. It provides over-voltage protection, over-current protection, under-voltage protection, on/off control and power good signal generating. OVP/UVP (Over/Under-Voltage Protection) monitors 3.3V, 5V and double 12V to protect our power supply and PC, FPO goes to high when one of these supply voltages exceeds their normal operation voltage range.
The power supply is turned on after 38mS de-bounce time when PSON signal is set from high to low. To turn off power supply, PSON signal is set from low to high and the de-bounce time is 115mS. When PGI input voltage level is lower than the internal 1.15V reference voltage, after 73uS de-bounce time, the PGO signal is pulled low.