DESCRIPTION
SG6105A controller is designed for switching-mode power supplies for desktop PCs. It provides all the functions necessary to monitor and control the output of the power supply. Remote ON/OFF control, power–good circuitry, and protection features against over-voltage and over-power are implemented. It directly senses all the output rails for OVP without the need for external dividers. An innovative AC-signal sampling circuitry provides a sufficient power-down warning signal for PG. 

FEATURES
„  PC half-bridge (or 494) power supply supervisor + two 431 + PWM 
„  High integration & few external components
„  Over-voltage protection for 3.3V, 5V, and 12V
„  Under-voltage protection for 3.3V, 5V, and 12V
„  Under-voltage protection for –12V and/or –5V 
„  Over-power and short-circuit protection
„  Power-down warning circuitry
„  Power-good circuitry
„  Delay time for PSON and PG signal
„  Remote ON/OFF function
„  On-chip oscillator and error amplifier
„  Two shunt regulators for 3.3V and 5V-standby
„  Latching PWM for cycle-by-cycle switching 
„  Push-pull PWM operation and totem pole outputs
„  Soft-start and maximum 93% duty cycle 

APPLICATIONS
Switching mode power supply for computers:
„  AT
„  NLX
„  SFX (micro-ATX)