General Description

The FAN5018B is a multi-phase DC-DC controller for implementing high-current, low-voltage, CPU core power regulation circuits. It is part of a chipset that includes external MOSFET drivers and power MOSFETS. The FAN5018B drives up to four synchronous-rectified buck channels in parallel. The multi-phase buck converter architecture uses interleaved switching to multiply ripple frequency by the number of phases and reduce input and output ripple currents. Lower ripple results in fewer components, lower component cost, reduced power dissipation, and smaller board area.

The FAN5018B features a high-bandwidth control loop to provide optimal response to load transients. The FAN5018B senses current using lossless techniques: Phase current is measured through each of the output inductors. This current information is summed, averaged and used to set the loadline of the output via programmable droop. The droop is temperature compensated to achieve precise loadline characteristics over the entire operating range. Additionally, individual phase current is measured using the RDS(ON) of the low-side MOSFETs. This information is used to dynamically balance/steer per-phase current. The phase currents are also summed and averaged for over-current detection.

Dynamic-VID technology allows on-the-fly VID changes with controlled, glitch-less output. Additionally, short-circuit protection, adjustable current limiting, over-voltage protection and power-good circuitry combine to ensure reliable and safe operation. FAN5018B is specified over the commercial temperature range of 0°C to +85°C and operates from a single +12V supply which simplifies design. FAN5018B is available in a 28L-TSSOP package.

Features

• Improved Noise Immunity

• Improved Load Line Accuracy

• TTL Compatible VID Inputs

• Fully Pin and Function compatible with existing FAN5018 and ADP3180 Controllers

• Precision Multi-Phase DC-DC Core Voltage Regulation

– ±14mV Output Voltage Accuracy Over Temperature

• Differential Remote Voltage Sensing

• Selectable 2-, 3-, or 4-Phase Operation

• Selectable VRM9 or VRM10 Operation

• Up to 1MHz per Phase Operation (4MHz ripple Frequency)

• Lossless Inductor Current Sensing for Loadline Compensation

– External Temperature Compensation

• Accurate Loadline Programming (Meets Intel® VRM/VRD10.x CPU Specifications)

• Accurate Channel-Current Balancing for Thermal Optimization and Layout Compensation

• Convenient 12V Supply Biasing

• 6-bit Voltage Identification (VID) Input

– .8375V to 1.600V in 12.5mV Steps

– Dynamic VID Capability with Fault-Blanking for glitch-less Output voltage Changes

• Adjustable Over Current Protection with Programmable Latch-Off Delay. Latch-Off Function may be Disabled

• Over-Voltage Protection – Internal OVP Crowbar Protection

• Package: 28L-TSSOP

Applications

• VRM/VRD 9.x and 10.x Computer DC/DC Converter

• High-Current, Low-Voltage DC/DC Rail