SG6105A_09 Datasheet, PDF (1/17 Pages) Fairchild Semiconductor – Power Supply Supervisor + Regulator + PWM

July 2009
SG6105A
Power Supply Supervisor + Regulator + PWM
Features
ƒ PC Half-Bridge (or 494) Power Supply Supervisor +
two 431 + PWM
ƒ High Integration with Few External Components
ƒ Over-Voltage Protection for 3.3V, 5V, and 12V
ƒ Under-Voltage Protection for 3.3V, 5V, and 12V
ƒ Under-Voltage Protection for -12V and/or -5V
ƒ Over-Power and Short-Circuit Protection
ƒ Power-Down Warning Circuitry
ƒ Power-Good Circuitry
ƒ Delay Time for PSON and PG Signal
ƒ Remote ON/OFF Function
ƒ On-Chip Oscillator and Error Amplifier
ƒ Two Shunt Regulators for 3.3V and 5V-Standby
ƒ Latching PWM for Cycle-by-Cycle Switching
ƒ Push-Pull PWM Operation and Totem Pole Outputs
ƒ Soft-Start and Maximum 93% Duty Cycle
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.
A built-in timer generates accurate timing for the control
circuit, including the PS-off delay. The cycle-by-cycle
PWM switching prevents the power transformer from
saturation and ensures the fastest response for the
short-circuit protection, which greatly reduces stress for
power transistors. Two internal precision TL431 shunt
regulators provide stable reference voltage and a driver
for 3.3V and 5V standby regulation.
Utilizing minimum external components, the SG6105A
includes the functions for push-pull and/or half-bridge
topology, decreasing production cost and PCB space,
and increasing the MTBF for power supply.
Applications
Switching mode power supply for computers:
ƒ AT
ƒ NLX
ƒ SFX (micro-ATX)
Ordering Information
Part
Number
SG6105ADZ
SG6105ADY
Operating
Temperature
Range
-40 to +105°C
-40 to +105°C
Eco Status
Package
Packing Method
RoHS
Green
20-pin Dual In-Line Package (DIP)
20-pin Dual In-Line Package (DIP)
Tube
Tube
For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2008 Fairchild Semiconductor Corporation
SG6105A • Rev. 1.0.2
www.fairchildsemi.com