MIC2202 Datasheet, PDF (1/18 Pages) Micrel Semiconductor – HIGH EFFICIENCY 2MHZ SYNCHRONOUS BUCK CONVERTER 1UP STABLE PWM REGULATOR

MIC2202
Micrel
MIC2202
High Efficiency 2MHz Synchronous Buck
Converter 1µF Stable PWM Regulator
General Description
The Micrel MIC2202 is a high efficiency 2MHz PWM synchro-
nous buck regulator. The fast 2MHz operation along with a
proprietary compensation scheme allows the smallest pos-
sible external components. The MIC2202 can operate with
a 1µF ceramic output capacitor and a small, low DC-resis-
tance, 2.2µH inductor, reducing system size and cost while
allowing a high level of efficiency.
The MIC2202 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 0.5V. The
MIC2202 implements a constant 2MHz pulse- width-modu-
lation (PWM) control scheme which reduces noise in sensi-
tive RF, audio, and communications applications. Addition-
ally, the MIC2202 can be synchronized to an external clock,
or multiple MIC2202s can easily be daisy-chained with the
SYNCLOCK feature.
The MIC2202 has a high bandwidth loop (up to 500kHz)
which allows ultra fast transient response times. This 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 MIC2202 is available in 10-pin MSOP and 3mm × 3mm
MLF™-10L package options with an operating junction
temperature range from –40°C to +125°C .
Features
• Input voltage range: 2.3V to 5.5V
• Output down to 0.5V/600mA
• 2MHz PWM operation
• Stable with 1µF ceramic output capcitor.
• Ultra-fast transient response (up to 500kHz GBW)
• Internal compensation
• All ceramic capacitors
• >95% efficiency
• Fully integrated MOSFET switches
• Easily synchronized to external clock
• SYNCLOCK feature to daisy chain multiple 2202s
• Requires only 4 external components
• 1% line and load regulation
• Logic controlled micropower shutdown
• Thermal shutdown and current limit protection
• 10-pin MSOP and 3mm×3mm MLF™-10L package
options
• –40°C to +125°C junction temperature range
Applications
• Cellular phones
• PDAs
• 802.11 WLAN power supplies
• FPGA/ASIC power supplies
• Dynamically adjustable power supply for CDMA/W-
CDMA RF power amps
• DSL modems
• Tape drives
Typical Application
2.2µH
V_IN
1
2.3V to 5.5V
2
SYNC_IN
3
SYNC_OUT
4
EN
5
10
9
10k
8
7
10nF
6
1.78k
V_OUT
3.3V
600mA
1µF
Adjustable Output Synchronous Buck Converter
100
95
90
85
80
75
70
65
60
0
Efficiency 3.3V_OUT
4.2V_IN
5V_IN
L = 2.2µH
C_OUT = 1µF
0.1 0.2 0.3 0.4 0.5 0.6
OUTPUT CURRENT (A)
MicroLeadFrame and MLF are trademarks of Amkor Technology, Inc.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
May 2004
1
M9999-052104