Description

Designed to provide the power supply requirements of printers,

office automation, industrial, and portable equipment, the

A4491providesthreehighcurrent,highperformance,switching

regulator outputs in a single package, saving space, cost and

component count.

High frequency switching allows selection of inexpensive

inductors and small ceramic output capacitors. The turn-on

cycles of the regulators are interleaved to minimize stresses on

the input capacitors and to reduce EMI. Independent Enable

pins simplify power sequencing and shutdown capabilities,

and a power-on-reset (POR) circuit with user configurable

delay indicates when enabled regulators are in specification.

4491-DS, Rev. 1

Features and Benefits

▪ Three buck converters in a single package

▪ 4.5 to 23 V input voltage range

▪ 550 kHz fixed frequency

▪ Multiphase switching for smaller components and

lower EMI

▪ Independent control of each converter for sequencing and

shutdown control

▪ Power-on-reset flag with adjustable delay

▪ Internal compensation to minimize components and

simply design

▪ 4 × 4 mm QFN Package, small PCB footprint

Triple Output Step-Down Switching Regulator

Package: 20-contact QFN (suffix ES)

Applications:

▪ Photo, inkjet, and portable printers

• Set-top boxes

• Tablet computing

• Other Consumer Electronics applications

• Point-of-sale applications

• Security systems

• Gaming machines

• Other Industrial applications

A4491

Approximate size

Microcontroller or

Controller Logic

GND

CP1 CP2

VCP

PGND

PORZ

ENB1

ENB2

ENB3

CPOR

VDD

A4491

VBB2

LX2

FB2

VBB3

LX3

FB3

VBB1

LX1

FB1

Typical Application

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