MIC2194_05 Datasheet, PDF (1/10 Pages) Micrel Semiconductor – 400kHz SO-8 Buck Control IC

MIC2194
MIC2194
400kHz SO-8 Buck Control IC
Micrel
General Description
Micrel’s MIC2194 is a high efficiency PWM buck control IC
housed in the SO-8 package. Its 2.9V to 14V input voltage
range allows it to efficiently step down voltages in 3.3V, 5V,
and 12V systems as well as 1- or 2-cell Li Ion battery powered
applications. The flexible architecture of the MIC2194 allows
for it to be configured as a buck or a buck-boost converter.
The MIC2194 solution saves valuable board space. The
device is housed in the space-saving SO-8 package, whose
low pin-count minimizes external components. Its 400kHz
PWM operation allows a small inductor and small output
capacitors to be used. The MIC2194 can implement all-
ceramic capacitor solutions.
The MIC2194 drives a high-side P-channel MOSFET. A low
output driver impedance of 2Ω allows the MIC2194 to drive
large external MOSFETs to generate a wide range of output
currents. The MIC2194 can achieve maximum duty cycles of
100%, which can be useful in low headroom applications.
The MIC2194 is available in an 8 pin SOIC package with a
junction temperature range of –40°C to +125°C.
Features
• 2.9V to 14V input voltage range
• 400kHz oscillator frequency
• PWM current mode control
• 2Ω output drivers
• 100% maximum duty cycle
• 0.5µA micro-power shutdown
• Programmable UVLO
• Front edge blanking
• Cycle-by-cycle current limiting
• Frequency foldback short circuit protection
• 8-lead SOIC package
Applications
• Point of load power supplies
• Negative voltage buck-boost power supplies
• Distributed power systems
• Base stations
• Wireless modems
• ADSL line cards
• Servers
• Step down conversion in 3.3V, 5V, 12V systems
• 1-and 2-cell Li Ion battery operated equipment
Typical Application
V_IN
12V
47µF
20V
(×2)
1µF
2.2nF
0.012Ω
MIC2194BM
VIN
CS
EN/
UVLO
OUTP
VDD
FB
2k _{COMP GND}
Si4431A
(×2)
5.2µH
B530 ^10k
3.32k
V_OUT
5V, 5A
220µF
10V
(×2)
Adjustable Output Buck Converter
V_IN
+3.3V
0.040Ω
Si9803
22µH
10µF
16V
10µF
16V
1µF
10nF
MIC2194BM
VIN
CS
EN/
UVLO
OUTP
VDD
FB
4.99k _{COMP GND}
B530
3.01k
1k
22nF
220µF
10V
(×2)
V_OUT
–5V, 0.6A
Positive-to-Negative Buck-Boost Converter
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
April 2005
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MIC2194