MIC2238_10 Datasheet, PDF (1/16 Pages) Micrel Semiconductor – 2.5MHz Dual Phase PWM Buck Regulator

MIC2238
2.5MHz Dual Phase
PWM Buck Regulator
General Description
Features
The Micrel MIC2238 is dual output 2-phase synchronous
buck (step down) PWM DC/DC switching regulator. Power
conversion efficiencies of above 95% are easily obtainable
for a wide range of applications and loads. An ultra-low
quiescent current of 28µA at light loads assures minimum
current draw in battery powered applications that require
standby modes. The 2.5MHz PWM operation of MIC2238
allows the use of miniature 1µH, 2.2µH or 4.7µH inductor
with the use of 2.2µF ceramic output capacitor.
The MIC2238 operates from 2.5V to 5.5V input and is
available in fixed output voltage versions to save space
and reduce external component count. The MIC2238-AA’s
(adjustable version) output voltage versions can be
programmed as low as 0.8V
• Input voltage range: 2.5V to 5.5V
• Dual output voltages running out of phase
• 28µA quiescent current
• Fixed output voltage versions
• Adjustable version down to 0.8V
• Low noise 2.5MHz PWM operation
• 800mA output current capability for each channel
• Stable with 2.2µH inductor, 2.2µF ceramic cap
• Automatic switching into light load mode of operation
• /FPWM pin allows low noise all-PWM mode operation
• Power good output with internal 5µA current source
allows sequencing with programmable delay time
For applications that require the lowest noise performance,
the /FPWM pin allows the automatic Trickle mode to be
disabled, remaining in full PWM mode. To maximize
battery life in low-dropout conditions, MIC2238 can
operate with a maximum duty cycle of 100%.
The MIC2238 is available in a space-saving 3mm x 3mm
MLF^®-12L package with a junction 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.
• Internal soft-start
• 1μA shutdown current
• Built-in soft-start circuitry
• Current limit protection
• Pb-Free 3mm x 3mm MLF^®-12L package
Applications
• Cellular phones
• PDAs
• Digital Cameras
• MP3 Players
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Typical Application
MLF and MicroLead Frame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
April 2010
M9999-040810-C