June 2000

1

MIC2141

MIC2141

Micrel

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

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 70

µA 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

•<2

µA shutdown current

•70

µA 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

Junction Temp. Range

Package

MIC2141-BM5

–40

°C to +85°C

SOT-23-5

Typical Application

MIC2141

Variable

(from DAC)

10

µF

10

µH

15

2

34

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0

5

10

15

20

25

V

Control Voltage

vs. Output Voltage

DAC-Controlled LCD Bias Voltage Supply