MIC22601

4 MHz, 6A Integrated Switch

Synchronous Buck Regulator

Ramp Control is a trademark of Micrel, Inc.

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

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

May 2009

M9999-050509-A

General Description

The Micrel MIC22601 is a high efficiency 6A Integrated

switch synchronous buck (step-down) regulator. The

MIC22601 is optimized for highest efficiency (greater than

90%), while still switching at 4MHz over a broad load

range with only 0.22µH inductor and down to 22µF output

capacitor. The ultra-high speed control loop keeps the

output voltage within regulation even under extreme

transient load swings commonly found in FPGAs and low

voltage ASICs. The output voltage can be adjusted down

to 0.7V to address all low voltage power needs. A full

range of sequencing and tracking options is available with

the MIC22601. The enable/delay pin, combined with the

power good PG/POR pin, allows multiple outputs to be

sequenced in any way during turn on and turn off. The RC

(Ramp Control™) pin allows the device to be connected to

another product in the MIC22xxx and/or MIC68xxx family,

to keep the output voltages within a certain ΔV on start up.

The MIC22601 is available in a 24-pin 4mm x 4mm MLF

®

package with a junction operating temperature range from

–40

°C to +125°C.

Data sheets and support documentation can be found on

Micrel’s web site at: www.micrel.com.

Features

• Input voltage range: 2.6V to 5.5V

• 4MHz PWM frequency

• Adjustable output voltage option down to 0.7V

• Output current to 6A

• Small Passive components: 0.22µH and 22µF

• Full sequence and tracking ability

• Power On Reset/Power Good

• Ultra fast transient response

–

Easy RC compensation

• 100% maximum duty cycle

• Fully integrated MOSFET switches

• Micro power shutdown

• Thermal shutdown and current limit protection

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

Applications

• High power density point of load conversion

• Servers and routers

• Blu-ray/DVD players and recorders

• Computer peripherals

• Base stations

• FPGA, DSP and low voltage ASIC power

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Typical Application

40

50

60

70

80

90

100

0123456

OUTPUT CURRENT (A)

Efficiency

vs. Load Current

L = 470nF

Figure 1. Typical Application Circuit, 6A 4MHz Synchronous Output Converter

Sequencing & Tracking