
Fairchild Semiconductor
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
• 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
Applications
• AMD Mobile Athlon™ CPU VCORE Regulator
• AMD Mobile Duron™ CPU VCORE Regulator