FAN5240

FAN5240 Multi-Phase PWM Controller for AMD Mobile AthlonTM and DuronTM

Datasheet preview, take a look at Datasheets before downloading (Data Sheet is available on manufacturer site)

FAN5240 Multi-Phase PWM Controller for AMD Mobile AthlonTM and DuronTM

March 2006

FAN5240 Multi-Phase PWM Controller for AMD Mobile AthlonTM and DuronTM
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:

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. Special measures are taken to allow the output to transition with controlled slew rate to comply with AMD s Power Now technology. The FAN5240 includes a precision reference, and a proprietary architecture with integrated compensation providing excellent static and dynamic core voltage regulation. The regulator includes special circuitry which balances the 2 phase currents for maximum efficiency. At light loads, when the filter inductor current becomes discontinuous, the controller operates in a hysteretic mode, dramatically improving system efficiency. The hysteretic mode of operation can be inhibited by the FPWM control pin. The FAN5240 monitors the output voltage and issues a PGOOD (Power-Good) when soft start is completed and the output is in
regulation. A pin is provided to add delay to PGOOD with an external capacitor. A built-in over-voltage protection (OVP) forces the lower MOSFET on to prevent the output from exceeding a set voltage. The PWM controller s overcurrent circuitry monitors the converter load by sensing the voltage drop across the lower MOSFET. The overcurrent threshold is set by an external resistor. If precision overcurrent protection is required, an optional external current-sense resistor may be used.

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

Ordering Information
Part Number
FAN5240QSC FAN5240QSCX FAN5240MTC FAN5240MTCX

Temperature Range
-10 C to 85 C -10 C to 85 C -10 C to 85 C -10 C to 85 C

Package
QSOP-28 QSOP-28 TSSOP-28 TSSOP-28

Packing
Rails Tape and Reel Rails Tape and Reel

2006 Fairchild Semiconductor Corporation

www.fairchildsemi.com

FAN5240 Rev. 1.2.0