MIC4722

3mm x 3mm 2.7MHz 3A PWM Buck Regulator

MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

September 2007

M9999-090507-B

General Description

The Micrel MIC4722 is a high efficiency PWM buck (step-

down) regulator that provides up to 3A of output current.

The MIC4722 operates at 2.7MHz that makes it suitable

for next generation XDSL modems requiring operating

frequencies in excess of 2.4MHz and has proprietary

internal compensation that allows a closed loop bandwidth

of over 200KHz.

The low on-resistance internal p-channel MOSFET of the

MIC4722 allows efficiencies over 92%, reduces external

components count and eliminates the need for an

expensive current sense resistor.

The MIC4722 operates from 2.7V to 5.5V input and the

output can be adjusted down to 1V. The devices can

operate with a maximum duty cycle of 100% for use in low-

dropout conditions.

The MIC4722 is available in the exposed pad 12-pin

3mm x 3mm MLF

range from –40°C to +125°C.

Features

•

2.7 to 5.5V supply voltage

•

2.7MHz PWM mode

•

Output current to 3A

•

>92% efficiency

•

100% maximum duty cycle

•

Adjustable output voltage option down to 1V

•

Ultra-fast transient response

•

Ultra-small external components

Stable with a 0.47µH inductor and a 4.7µF output

capacitor

•

Fully integrated 3A MOSFET switch

•

Micropower shutdown

•

Thermal shutdown and current limit protection

•

Pb-free 12-pin 3mm x 3mm MLF

•

–40

°C to +125°C junction temperature range

Applications

•

5V or 3.3V Point of Load Conversion

•

Telecom/Networking Equipment

•

Set Top Boxes

•

Storage Equipment

•

Video Cards

Typical Application

MIC4722

3A 2.7MHz Buck Regulator