The FAN5031 device is a multi-phase buck switching regulator controller, that is optimized to convert a 12V input supply to the processor core voltage required by high performance Intel processors. It has an internal 8-bit DAC that converts a digital voltage identification (VID) code, that is sent from the processor, to set the output voltage between 0.5V and 1.6V in 6.25 mV steps. It outputs a PWM signals to external MOSFET drivers that, in turn, drive the switching power MOSFETs. The switching frequency of the design is easily programmable by a single resistor value and the number of phases can be programmed to support 2, 3, or 4 phase applications. The FAN5031 also includes programmable no-load offset and droop functions to adjust the output voltage as a function of the load current, as required by the Intel specifications. The FAN5031 also provides an accurate and reliable short circuit protection function with an adjustable over current set-point. The FAN5031 is specified over the commercial temperature range of 0°C to +85°C and is available in a 40-lead MLP package.

• Selectable 2, 3, or 4 phase operation at up to 1MHz per phase
• ±7.7mV worst-case differential sensing error over temperature
• Active current balancing between the output phases
• Power good and Crowbar blanking supports on-the-fly VID code changes
• 0.5V to 1.6V output
• Fully compliant to both Intel’s VR10 and VR11 specifications
• Selectable VR10 extended (7 bit) and VR11 (8 bit) VID tables
• Programmable soft start ramp
• Programmable short circuit protection and latch-off delay

• Desktop PC/Server processor power supplies for existing and next generation Intel processors
• VRM modules