A4491 Datasheet, PDF (1/16 Pages) Allegro MicroSystems – Designed to provide the power supply requirements of printers, office automation, industrial, and portable equipment, the A4491 provides three high current,

A4491
Triple Output Step-Down Switching Regulator
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
Package: 20-contact QFN (suffix ES)
Approximate size
Description
Designed to provide the power supply requirements of printers,
office automation, industrial, and portable equipment, the
A4491 provides three high current, high performance, 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.
Continued on the next page…
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
V_BB
Microcontroller or
Controller Logic
4491-DS, Rev. 1
Typical Application
VDD CP1 CP2
PORZ
CPOR
VCP _VBB1
LX1
ENB1
ENB2
ENB3
A4491
FB1
VBB2
LX2
PGND
FB2
VBB3
LX3
GND
FB3
V_REG1
V_REG2
V_REG3