FAN5018B View Datasheet(PDF) - Fairchild Semiconductor

Part Name

Description

Manufacturer

FAN5018B

6-Bit VID Controller 2-4 Phase VR10.X Controller

Fairchild Semiconductor 

www.fairchildsemi.com

FAN5018B

6-Bit VID Controller 2-4 Phase VR10.X Controller

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

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 exter-

nal MOSFET drivers and power MOSFETS. The

FAN5018B drives up to four synchronous-rectified buck

channels in parallel. The multi-phase buck converter archi-

tecture uses interleaved switching to multiply ripple fre-

quency 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 tem-

perature compensated to achieve precise loadline character-

istics 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 dynam-

ically 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 protec-

tion 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 sin-

gle +12V supply which simplifies design. FAN5018B is

available in a 28L-TSSOP package.

Block Diagram

VIN

Φ1

FAN5009

Φ2

FAN5018B

VIN

Φ3

Φ4

FAN5009

VOUT

REV. 1.0.0 Jul/15/05

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