MIC2203 Datasheet, PDF (1/13 Pages) Micrel Semiconductor – High Efficiency 1MHz Synchronous Buck Regulator

MIC2203
High Efficiency 1MHz Synchronous
Buck Regulator
General Description
The Micrel MIC2203 is a high efficiency 1MHz PWM
synchronous buck switching regulator. The MIC2203
features low noise constant frequency PWM
operation with a low dynamic supply current of
<1mA. The low noise and efficient operation both
make the MIC2203 well suited for sensitive RF, and
audio power applications.
The MIC2203 operates from 2.3V to 5.5V input and
can supply over 300mA of output current with output
voltages down to 0.5V. Additionally, the MIC2203
can be synchronized to an external clock, or multiple
MIC2203s can easily be daisy-chained with the
SYNCLOCK feature.
The MIC2203 has a high loop bandwidth with
corresponding ultra fast transient response times.
This reduces the output capacitor size, and is very
useful when powering applications that require fast
dynamic response such as CPU cores and RF
circuitry in high performance cellular phones and
PDAs.
The MIC2203 is available in 10-pin MSOP and
3mm x 3mm MLF™-10L package options with an
operating junction temperature range from –40ºC to
125ºC.
Features
• Input voltage range: 2.3V to 5.5V
• Output voltage adjustable down to 0.5V
• 300mA output current
• Constant 1MHz PWM switching frequency
• > 95% efficiency
• < 1mA switching supply current
• < 350µA static quiescent current
• < 1µA shutdown current
• All-ceramic capacitors
• Easily synchronized to external clock
• SYNCLOCK feature to daisy chain multiple
devices
• Thermal shutdown and current limit protection
• 10 pin MSOP, and 3mm x 3mm MLF-10L package
options
• –40ºC to +125ºC junction temperature range
Applications
• 802.11 WLAN modules
• MD players
• MP3 players
_____________________________________________________________________
Typical Application
10µH
MIC2203BMM
2.3V to 5.5V
1µF
1
SYNC_IN ²
3
SYNC_OUT
4
EN
5
10
9
R1
10k
8
7
10nF
6
R2
3.83k
High Efficiency Buck Regulator
1.8V
300mA
2.2µF
MicroLead Frame and MLF are trademarks of Amkor Technologies.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax [phone] • http://www.micrel.com
December 2004
M9999-120604
[phone]