FAN5240

www.fairchildsemi.com 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 5V 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 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 pha...