April 2005

1

M9999-042205

MIC2204

Micrel, Inc.

Typical Application

MIC2204

High-Efficiency 2MHz Synchronous Buck Converter

General Description

The Micrel MIC2204 is a high-efficiency, 2MHz PWM syn-

chronous buck switching regulator. Power conversion effi-

ciency of above 95% is easily obtainable over a wide range

of applications. A proprietary internal compensation tech-

nique ensures stability with the smallest possible inductor

and ceramic output capacitor.

The MIC2204 operates from 2.3V to 5.5V input and features

internal power MOSFETs that can supply over 600mA of

output current with output voltages down to 1V. The MIC2204

implements a constant 2MHz pulse-width-modulation (PWM)

control scheme which reduces spurious noise in sensitive RF

and communication applications. Additionally, the MIC2204

can be synchronized to an external clock, or multiple MIC2204s

can easily be daisy-chained with the SYNCLOCK feature.

The MIC2204 has a high bandwidth loop (typ. 200kHz) which

allows ultra-fast transient response times. This is very useful

when powering applications that require fast dynamic re-

sponses, such as the CPU cores and RF circuitry in high-

performance cellular phones and PDAs.

The MIC2204 is available in 10-pin MSOP and 3mm × 3mm

MLF™-10L package options with an operating junction tem-

perature range from –40°C to 125°C .

Features

•Input voltage range: 2.3V to 5.5V

• Output down to 1V/ 600mA

• 2MHz PWM operation

•Ultra-fast transient response (typical 200kHz GBW)

•Internal compensation

•All ceramic capacitors

• >95% efficiency

• Fully integrated MOSFET switches

• Easily synchronized to external clock

• SYNCLOCK feature to daisy-chain multiple 2204s

• <340µA quiescent current

• Logic controlled micropower shutdown

• Thermal shutdown and current limit protection

• 10-pin MSOP and 3mm×3mm MLF™-10L

• –40°C to +125°C junction temperature range

Applications

•High-efficiency portable power

• Cellular phones

• PDAs

• 802.11 WLAN power supplies

• RF power supplies

•Li Ion battery powered applications

10nF

4.7µH

3.3V

500mA

2.3V to 6V

4.7µF

EN

6

5

1

SYNC_IN

SYNC_OUT

10

9

8

7

2

3

4

MIC2204BMM

Adjustable Output Synchronous Buck Converter

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

MLF and MicroLeadFrame are trademarks of Amkor Technology, Inc.

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0

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500

OUTPUT CURRENT (mA)

Efficiency

vs. Output Current

3.6V

IN

4.2V

IN

3.3V

OUT

5V

IN