MIC2141 Datasheet, PDF (1/16 Pages) Micrel Semiconductor – Micropower Boost Converter Preliminary Information

MIC2141
Micrel
MIC2141
Micropower Boost Converter
Preliminary Information
General Description
The MIC2141 is a micropower boost switching regulator that
can operate from 3- or 4-cell nickel-metal-hydride batteries or
a single Li-ion cell. This regulator employs a constant 330kHz,
fixed 18% duty-cycle, gated-oscillator architecture.
The MIC2141 can be used in applications where the output
voltage must be dynamically adjusted. The device features a
control signal input which is used to proportionally adjust the
output voltage. The control signal input has a gain of 6,
allowing a 0.8V to 3.6V control signal to vary a 4.8V to 22V
output.
The MIC2141 requires only three external components to
operate and is available in a tiny 5-lead SOT-23 package for
space and power-sensitive portable applications. The
MIC2141 draws only 70µA of quiescent current and can
operate with an efficiency exceeding 85%.
Features
• Implements low-power boost, SEPIC, or flyback
• 2.5V to 14V input voltage
• 330kHz switching frequency
• <2µA shutdown current
• 70µA quiescent current
• 1.24V bandgap reference
• typical output current 1mA to 10mA
• SOT-23-5 Package
Applications
• LCD bias supply
• CCD digital camera supply
Ordering Information
Part Number
MIC2141-BM5
Junction Temp. Range
–40°C to +85°C
Package
SOT-23-5
Typical Application
V_C*
(from DAC)
10µH
MIC2141
1
5
2
3
4
Variable
V_OUT
10µF
Control Voltage
vs. Output Voltage
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
00
5 10 15 20 25
V_OUT (V)
DAC-Controlled LCD Bias Voltage Supply
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
June 2000
1
MIC2141