MIC22400
4A Integrated Switch Synchronous
Buck Regulator with Frequency
Programmable up to 4MHz
General Description
The Micrel MIC22400 is a high efficiency 4A integrated
switch synchronous buck (step-down) regulator. The
MIC22400 is optimized for highest efficiency and achieves
over 90% efficiency while still switching at 1MHz over a
broad load range. 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 sequence options are available with the
MIC22400. The enable/delay pin combined with the power
good pin allows multiple outputs to be sequenced in any
way on turn on and turn off. The RC (Ramp Control™) pin
allows the device to be connected to another MIC22400
family of products to keep the output voltages within a
certain
∆V
on start up.
The MIC22400 is available in a 20-pin 3mm x 4mm MLF
®
and thermally enhanced 20-pin e-TSSOP with a junction
operating 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
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Input voltage range: 2.6V to 5.5V
Output voltage adjustable down to 0.7V
Output current up to 4A
Full sequencing and tracking ability
Power on reset
Efficiency > 90% across a broad load range
Programmable frequency 800kHz to 4MHz
Easy RC compensation
Ultra fast transient response
100% maximum duty cycle
Fully integrated MOSFET switches
Micropower shutdown
Thermal shutdown and current limit protection
20-pin 3mm x 4mm MLF
®
20-pin e-TSSOP
–40°C to +125°C junction temperature range
Applications
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High power density point of load conversion
Servers and routers
DVD recorders
Computing peripherals
Base stations
FPGAs, DSP and low voltage ASIC power
Typical Application
Efficiency V
O
= 3.3V
100
95
90
85
80
75
70
65
60
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
OUTPUT CURRENT (A)
MIC22400 4A Synchronous Buck Regulator
Ramp Control is a trademark of Micrel, Inc.
MLF and
MicroLeadFrame
are registered trademarks of Amkor Technology, Inc.
Sequencing & Tracking
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
February 2008
M9999-022108-A
MICREL [ MICREL SEMICONDUCTOR ]
