General Description

The FAN5240 is a single output 2-Phase synchronous buck controller to power AMD’s mobile CPU core. The FAN5240 includes a 5-bit digital-to-analog converter (DAC) that adjusts the core PWM output voltage from 0.925VDC to 2.0VDC, which may be changed during operation.

Features

■ CPU Core power: 0.925V to 2.0V output range

■ ±1 reference precision over temperature

■ Dynamic voltage setting with 5-bit DAC

■ 6V to 24V input voltage range

■ 2 phase interleaved switching

■ Active droop to reduce output capacitor size

■ Differential remote voltage sense

■ High efficiency:

>90 efficiency over wide load range

>80 efficiency at light load

■ Excellent dynamic response with Voltage

Feed-Forward and Average Current Mode control

■ Dynamic duty cycle clamp minimizes inductor current

build up

■ Lossless current sensing on low-side MOSFET or

Precision current sensing using sense resistor

■ Fault protections: Over-voltage, Over-current, and

Thermal Shut-down

■ Controls: Enable, Forced PWM, Power Good, Power

Good Delay

■ QSOP28, TSSOP28

Applications

■ AMD Mobile Athlon? CPU VCORE Regulator

■ Graphic chip VCORE Regulator