FAN5232

www.fairchildsemi.com FAN5232 Adjustable PWM Buck Controller for LCD PCs Features Three outputs: Adjustable Buck, 3.3V-Always, 5V-Always Adjustable synchronous switcher, 5V – 80% Vin 1% internal reference precision Current mode with voltage feed-forward Precision current limit option Charge pump works at all loads No shoot-through current Independent shutdown pins for ACPI Power Good, input UVLO, output OV 5.6V to 24V input voltage range Description The FAN5232 is a high efficiency and high precision DC/DC controller for PCs. It has a synchronous switcher whose output can be adjusted from 5V up to 80% of Vin. It also has two linear regulators for standby, 3.3V and 5V. The PWM utilizes both input and output voltage feedback in a current-mode control, allowing for fast and stable loop response over a wide range of input and output variations. Synchronous switching provides best efficiency over a wide range of loads. Current sense based on MOSFET RDS,on gives maximum efficiency, while also permitting use of an optional sense resistor for high precision. The FAN5232 is available in a 14 pin TSSOP package. Applications LCD PCs Notebook PCs and PDAs Hand-held portable instruments Block Diagram Vin = 16–22V 1 3.3V-Always 5V-Always 2 3 FAN5232 4 SDWN SDNADJ PWRGD 5 6 7 14 13 12 11 10 9 8 + 12V @ 8A REV. 1.1.1 10/7/02 FAN5232 PRODUCT SPECIFICATION Pin Assignments VBATT 3V_ALWAYS 5V_ALWAYS AGND SDWN SDNADJ PWRGD 1 2 3 4 5 6 7 14 13 12 11 10 9 8 CPUMP H...