This document describes the features and characteristics of Fairchild Semiconductor's FAN5091 product. The FAN5091 is a synchronous multi-slice DC-DC controller IC that provides a highly accurate, programmable output voltage for all high-performance processors. It features programmable output, two interleaved synchronous slices, current sharing, remote sense, and more.
The FAN5091 is a two‑slice interleaved synchronous buck‑converter controller IC designed for high‑performance processors. It offers programmable output voltage from 1.10 V to 1.85 V in 25 mV steps, a wide programmable frequency range (200 kHz‑2 MHz), 100 ns response time, and built‑in current sharing, remote sensing, and active droop control. The device drives N‑channel MOSFETs and includes integrated high‑current gate drivers, power‑good, over‑voltage, under‑voltage, and soft‑start functions.
The datasheet details pin assignments for dual‑slice operation, electrical specifications such as 50 A output current, 85 % peak efficiency, and absolute maximum ratings. Mechanical information lists the 24‑pin TSSOP package dimensions. Typical applications include VRM supplies for Pentium IV and Athlon processors, as well as programmable step‑down power supplies.
| Output Voltage Range | 1.10 V to 1.85 V (25 mV steps) |
|---|---|
| Maximum Output Current | 50 A |
| Programmable Switching Frequency | 200 kHz to 2 MHz |
| Package Type | 24‑pin TSSOP |
| Supply Voltage (VCC) Max | 15 V |
| Efficiency (at full load) | 85 % |
| Response Time | 100 ns |
| Ambient Operating Temperature | 0 °C to 70 °C |
The output can be programmed from 1.10 V to 1.85 V in 25 mV steps.
It is rated for up to 50 A of output current.
The device is supplied in a 24‑pin TSSOP package.
The frequency can be set between 200 kHz and 2 MHz.