LM4121

Precision Micropower Low Dropout Voltage Reference

General Description

The LM4121 is a precision bandgap voltage reference avail-

able in a fixed 1.25V and adjustable version with up to 5 mA

current source and sink capability.

This series reference operates with input voltages as low as

1.8V and up to 12V consuming 160 µA (Typ.) supply current.

In power down mode, device current drops to less than 2 µA.

The LM4121 comes in two grades A and Standard. The best

grade devices (A) have an initial accuracy of 0.2%, while the

standard have an initial accuracy of 0.5%, both with a

tempco of 50ppm/˚C guaranteed from −40˚C to +125˚C.

The very low operating voltage, low supply current and

power-down capability of the LM4121 makes this product an

ideal choice for battery powered and portable applications.

The device performance is guaranteed over the industrial

temperature range (−40˚C to +85˚C), while certain specs are

guaranteed over the extended temperature range (−40˚C to

+125˚C). Please contact National for full specifications over

the extended temperature range. The LM4121 is available in

a standard 5-pin SOT-23 package.

Features (LM4121-1.2)

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Small SOT23-5 package

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Low voltage operation

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High output voltage accuracy:

0.2%

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Source and Sink current output:

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Supply current:

160 µA Typ.

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Low Temperature Coefficient:

50 ppm/˚C

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Enable pin

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Output voltages:

1.25V and Adjustable

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Industrial temperature Range:

−40˚C to +85˚C

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(For extended temperature range, −40˚C to 125˚C,

contact National Semiconductor)

Applications

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Portable, battery powered equipment

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Instrumentation and process control

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Automotive & Industrial

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Test equipment

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Data acquisition systems

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Precision regulators

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Battery chargers

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Base stations

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Communications

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Medical equipment

Connection Diagram

LM4121-1.2 Block Diagram

DS101291-1

* Resistors are removed on the LM4121-ADJ

†LM4121-ADJ only

DS101291-2

Refer to the Ordering Information Table in this Data Sheet for Specific

Part Number

SOT23-5 Surface Mount Package

DS101291-35

April 2000

© 2000 National Semiconductor Corporation

DS101291

www.national.com