October 2003

1

MIC5271

MIC5271

Micrel

MIC5271

General Description

The MIC5271 is a µCap 100mA negative regulator in a

SOT-23-5 package. With better than 2% initial accuracy, this

regulator provides a very accurate supply voltage for applica-

tions that require a negative rail. The MIC5271 sinks 100mA

of output current at very low dropout voltage (600mV maxi-

mum at 100mA of output current).

The µCap regulator design is optimized to work with low-

value, low-cost ceramic capacitors. The output typically re-

quires only a 1µF capacitance for stability.

Designed for applications where small packaging and effi-

ciency are critical, the MIC5271 combines LDO design exper-

reduce power dissipation. Ground current is optimized to help

improve battery life in portable applications. The MIC5271

also includes a TTL-compatible enable pin, allowing the user

to put the part into a zero-current off-mode.

The MIC5271 is available in the SOT-23-5 package for space

saving applications and it is available with an adjustable

output.

Data sheets and support documentation can be found on

Micrel’s web site at www.micrel.com.

Typical Application

Features

• Stable with ceramic or tantalum capacitor

• Positive and negative enable thresholds

• Low dropout voltage: 500mV @ 100mA

• Low ground current: 35µA @ load = 100µA

• Tight initial accuracy: ±2%

• Tight load and line regulation

• Thermal shutdown

• Current limiting

• Zero-current off-mode

Applications

• GaAsFET bias

• Portable cameras and video recorders

• PDAs

• Battery-powered equipment

• Post-regulation of DC-DC converters

IttyBitty is a registered trademark of Micrel, Inc.

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

Ordering Information

Part Number

Marking

Voltage*

Junction Temp. Range

Package

MIC5271BM5

L9AA

Adj.

–40°C to +125°C

SOT-23-5

MIC5271-3.0BM5

L930

–3.0V

–40°C to +125°C

SOT-23-5

MIC5271-5.0BM5

L950

–5.0V

–40°C to +125°C

SOT-23-5

* For other voltage options, please contact Micrel Marketing.

MIC5271BM5

GND

EN

–OUT

–IN

1µF

10µF

–5.0V

–6.0V

2

5

1

4

3

V

R1

R2

OUT

ADJ

Regulator With Adjustable Output

-5

-4

-3

-2

-1

0

1

2

3

4

5

-3

-5

-7

-9

-11 -13 -15

SUPPLY VOLTAGE (V)

Enable Input

Regulator On

Regulator On

Regulator Off