FAN5031MPX

The FAN5031MPX from ON Semiconductor is a multi-phase buck switching regulator controller optimized for converting a 12V input supply to the processor core voltage required by high-performance Intel processors. This device features an internal 8-bit DAC that converts a digital voltage identification (VID) code to set the output voltage between 0.5V and 1.6V in 6.25 mV steps.

Key features include selectable 2, 3, or 4 phase operation at up to 1MHz per phase, ±7.7mV worst-case differential sensing error over temperature, and active current balancing between output phases. It supports on-the-fly VID code changes with power good and crowbar blanking. The switching frequency is programmable by a single resistor value, and the number of phases can be set for 2, 3, or 4 phase applications.

The FAN5031MPX is fully compliant with Intel's VR10 and VR11 specifications, offering selectable VR10 extended (7-bit) and VR11 (8-bit) VID tables. It also includes programmable soft-start ramp and programmable short circuit protection with an adjustable overcurrent set-point. The controller operates over a commercial temperature range of 0°C to +85°C and is available in a 40-lead MLP package.

This controller is ideal for desktop PC and server processor power supplies, as well as VRM modules. It outputs PWM signals to external MOSFET drivers, which in turn drive the switching power MOSFETs. The device also provides programmable no-load offset and droop functions to adjust the output voltage as a function of load current, as required by Intel specifications.