MIC2142_07 Datasheet, PDF (1/17 Pages) Micrel Semiconductor – Micropower Boost Converter

MIC2142
Micropower Boost Converter
General Description
Features
The MIC2142 is a micropower boost switching regulator
housed in a SOT23-5 package. The input voltage range is
between 2.2V to 16V, making the device suitable for one-
cell Li Ion and 3 to 4-cell alkaline/NiCad/NiMH applica-
tions. The output voltage of the MIC2142 can be adjusted
up to 22V.
• 2.2V to 16V input voltage
• Up to 22V output voltage
• 330kHz switching frequency
• 0.1µA shutdown current
• 85µA quiescent current
The MIC2142 is well suited for portable, space-sensitive
applications. It features a low quiescent current of 85µA,
and a typical shutdown current of 0.1µA. It’s 330kHz
operation allows small surface mount external components
to be used. The MIC2142 is capable of efficiencies over
85% in a small board area.
The MIC2142 can be configured to efficiently power a
variety of loads. It is capable of providing a few mA output
for supplying low power bias voltages; it is also capable of
providing the 80mA needed to drive 4 white LEDs.
• Implements low-power boost, SEPIC, or flyback
• SOT23-5 package
Applications
• LCD bias supply
• White LED driver
• 12V Flash memory supply
• Local 3V to 5V conversion
The MIC2142 is available in a SOT23-5 package with an
ambient operating temperature range from –40°C to
+85°C.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
___________________________________________________________________________________________________________
Typical Application
2.8V to 4.7V
V_IN
C_IN
10µF
L1
33µH
D1
+5V @60mA
MIC2142
1 ^{VCC SW} 3
FB ₄
5 ^{EN GND} 2
R2
365k
R1
124k
C_OUT
22µF
Typical Configuration
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.400
Efficiency
vs. Output Current
V_IN = 4.2V
V_IN = 3.0V
10 20 30 40 50 60 70
OUTPUT CURRENT (mA)
Efficiency vs. Output Current
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
October 2007
M9999-102507