The WT7511 provides protection circuits, power good output (PGO), fault protection latch (FPL_N), and a protection detector function (PDON_N) control. It can minimize external components of switching power supply systems in personal computer. The Over Voltage Detector (OVD) monitors 3.3V, 5V, 12V input voltage level. When OVD detect the fault voltage level, the FPL_N is latched HIGH and PGO go low. The latch can be reset by PDON_N goo HIGH. There is 2.4 ms delay time for PDON_N turn off FPL_N. When OVD and UVD detect the right voltage level, the power good output (PGO) will be issue.