The WT7515 provides protection circuits, power good output (PGO), fault protection latch (FPOB), and a protection detector function (PSONB) control. It can minimize external components of switching power supply systems in personal computer. The Over / Under Voltage Detector (OVD / UVD) monitors 3.3V, 5V, 12V input voltage level. The Over Current Detector (OCD) monitor IS33, IS5, IS12 input current sense. When OVD or UVD or OCD detect the fault voltage level, the FPOB is latched HIGH and PGO go low. The latch can be reset by PSONB go HIGH. There is 2.4 ms delay time for PSONB turn off FPOB. When OVD and UVD and OCD detect the right voltage level, the power good output (PGO) will be issue.