SG6521

SG6521 — PC Power Supply Supervisors September 2008 SG6521 — PC Power Supply Supervisors Features ƒ Two 12V Sense Input Pins: VS12 and VS12B ƒ Over-Voltage Protection (OVP) for 3.3V, 5V, and two 12V ƒ Over-Current Protection (OCP) for 3.3V, 5V, and two 12V ƒ Under-Voltage Protection (UVP) for 3.3V, 5V, and two 12V ƒ Open-Drain Output for PGO and FPO Pins ƒ 300ms Power-Good Delay ƒ 2.8ms PSON Control to FPO Turn-off Delay ƒ 48ms PSON Control Delay ƒ No Lock-up During the Fast AC Power On/Off ƒ Wide Supply Voltage Range: 4V to 15V ƒ Over-Temperature Protection (OTP) ƒ Additional Protection Input (Pext) Applications ƒ Switch-Mode Power Supplies with Active PFC ƒ Servo System Power Supplies ƒ PC-ATX Power Supplies Description The SG6521 is designed to provide the supply voltage, current supervisor, remote on/off (PSON), power good (PGO) indicator, and fault protection (FPO) functions for switching power systems. For supervisory functions, it provides the over-voltage protection (OVP) for 3.3V, 5V, and two 12V; overcurrent protection (OCP) for 3.3V, 5V, and two 12V; under-voltage protection (UVP) for 3.3V, 5V, and two 12V. When 3.3V, 5V, or 12V voltage decreases to 2.3V, 3.5V, and 9V, respectively, the under-voltage protection function is enabled. FPO is set HIGH to turn off the PWM controller IC. The voltage difference across external current shunt is used for OCP functions. An external resistor can be used to adjust protection threshold. An additional protection input pin pr...