描述 Description

The FAN5250 is a single output power controller to power mobile CPU cores. The FAN5250 includes a 5-bit digital-toanalog converter (DAC) that adjusts the core PWM output voltage from 0.6VDC to 1.75VDC, and may be changed during operation. Special measures are taken to allow the output to transition with controlled slew rate to comply with Transmeta’s LongRun? and Intel’s P3-M Speed-Step? requirements. The FAN5250 includes a precision reference, and a proprietary architecture with integrated compensation providing excellent static and dynamic core voltage regulation.

特性 Features

? High efficiency over wide load range

? Non dissipative current-sense; uses MOSFET RDS(ON) or

can use optional Current-Sense resistor for greater

precision

? Overcurrent protection

? Powerful drivers for N-Channel MOSFETs with adaptive

dead time

? Precision core voltage control

? Remote “Kelvin” sensing

? Summing current-mode control with programmable

Active Droop for Optimum Transient Response and

Lower Processor Power Dissipation

? 5-Bit Digital Output Voltage Selection

? Wide Range output voltage: 0.6 VDC to 1.0 VDC in

25mV Steps, and from 1.0 VDC to 1.75 VDC in 50mV

Steps

? “On-the-Fly” VID code change with programmable slew

rate

? Alternative input to set output voltage during start-up or

power saving modes

? Forced continuous conduction mode of operation

? Output voltage (Power-Good) monitor

? No negative core voltage on turn-off

? Over-Voltage, Under-Voltage and Over-Current fault

monitors

? Selectable 300/600kHz Switching Frequency

Applications

? Transmeta’s Crusoe? CPU core power

? Intel P3-M? processor (IMVP-2)