June 2006

1

M9999-060906

Typical Applications

1

3

2

0.1µF

22µF

tantalum

2.5V ±1%

≥ 3.0V

MIC5209-2.5BS

3.3V Nominal-Input Slot-1

Power Supply

1

2

3

4

8

7

6

5

MIC5209-5.0BM

2.2µF

tantalum

5V

470pF

(OPTIONAL)

6V

ENABLE

SHUTDOWN

Ultra-Low-Noise 5V Regulator

MIC5209

500mA Low-Noise LDO Regulator

General Description

The MIC5209 is an efficient linear voltage regulator with very

low dropout voltage, typically 10mV at light loads and less

than 500mV at full load, with better than 1% output voltage

accuracy.

Designed especially for hand-held, battery-powered devices,

the MIC5209 features low ground current to help prolong

battery life. An enable/shutdown pin on SO-8 and TO-263-

5 versions can further improve battery life with near-zero

shutdown current.

Key features include reversed-battery protection, current

limiting,overtemperatureshutdown,ultra-low-noisecapability

(SO-8 and TO-263-5 versions), and availability in thermally

efficient packaging. The MIC5209 is available in adjustable

or fixed output voltages.

For space-critical applications where peak currents do not

exceed 500mA, see the MIC5219.

Features

®

®

• Guaranteed 500mA output over the full operating

temperature range

• Low 500mV maximum dropout voltage at full load

• Extremely tight load and line regulation

• Thermally-efficient surface-mount package

• Low temperature coefficient

• Current and thermal limiting

• Reversed-battery protection

• No-load stability

• 1% output accuracy

• Ultra-low-noise capability in SO-8 and TO-263-5

• Ultra-small 3mm x 3mm MLF™ package

Applications

• Pentium II Slot 1 and Slot 2 support circuits

• Laptop, notebook, and palmtop computers

• Cellular telephones

• Consumer and personal electronics

• SMPS post-regulator/dc-to-dc modules

• High-efficiency linear power supplies

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com