Electronico

LM134/LM234/LM334
3-Terminal Adjustable Current Sources
General Description
The LM134/LM234/LM334 are 3-terminal adjustable current
sources featuring 10,000:1 range in operating current, excellent current regulation and a wide dynamic voltage range of
1V to 40V. Current is established with one external resistor
and no other parts are required. Initial current accuracy is
± 3%. TheLM134/LM234/LM334 are true floating current
sources with no separate power supply connections. In addition, reverse applied voltages of up to 20V will draw only a
few dozen microamperes of current, allowing the devices to
act as both a rectifier and current source in AC applications.
The sense voltage used to establish operating current in the
LM134 is 64mV at 25˚C and is directly proportional toabsolute temperature (˚K). The simplest one external resistor
connection, then, generates a current with ≈+0.33%/˚C temperature dependence. Zero drift operation can be obtained
by adding one extra resistor and a diode.
Applications for the current sources include bias networks,
surge protection, low power reference, ramp generation,

LED driver, and temperature sensing. The LM234-3 and
LM234-6are specified as true temperature sensors with
guaranteed initial accuracy of ± 3˚C and ± 6˚C, respectively.
These devices are ideal in remote sense applications because series resistance in long wire runs does not affect accuracy. In addition, only 2 wires are required.
The LM134 is guaranteed over a temperature range of
−55˚C to +125˚C, the LM234 from −25˚C to +100˚C and the
LM334 from 0˚Cto +70˚C. These devices are available in
TO-46 hermetic, TO-92 and SO-8 plastic packages.

Features
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Operates from 1V to 40V
0.02%/V current regulation
Programmable from 1µA to 10mA
True 2-terminal operation
Available as fully specified temperature sensor
± 3% initial accuracy

Connection Diagrams
SO-8
Surface Mount Package

SO-8 Alternative Pinout
Surface MountPackage

DS005697-12

DS005697-24

Order Number LM334M or
LM334MX
See NS Package Number M08A

TO-46
Metal Can Package

DS005697-25

Order Number LM334SM or
LM334SMX
See NS Package Number M08A

V− Pin is electrically connected to case.

Bottom View
Order Number LM134H,
LM234H or LM334H
See NS Package
Number H03H

TO-92 Plastic Package

DS005697-10

Bottom View
OrderNumber LM334Z, LM234Z-3 or LM234Z-6
See NS Package Number Z03A

© 2000 National Semiconductor Corporation

DS005697

www.national.com

LM134/LM234/LM334 3-Terminal Adjustable Current Sources

March 2000

LM134/LM234/LM334

Absolute Maximum Ratings (Note 1)

LM234/LM234-3/LM234-6
−25˚C to +100˚C
LM334
0˚C to +70˚C
Soldering Information
TO-92 Package (10 sec.)
260˚C
TO-46Package (10 sec.)
300˚C
SO Package
Vapor Phase (60 sec.)
215˚C
Infrared (15 sec.)
220˚C
See AN-450 “Surface Mounting Methods and Their Effect on
Product Reliability” (Appendix D) for other methods of soldering surface mount devices.

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability andspecifications.
V+ to V− Forward Voltage
LM134/LM234/LM334
LM234-3/LM234-6
V+ to V− Reverse Voltage
R Pin to V− Voltage
Set Current
Power Dissipation
ESD Susceptibility (Note 6)
Operating Temperature Range (Note 5)
LM134

40V
30V
20V
5V
10 mA
400 mW
2000V
−55˚C to +125˚C

Electrical Characteristics (Note 2)
Parameter

Conditions

LM134/LM234
Min

Typ

LM334
Max

Min

TypUnits
Max

Set Current Error, V+ =2.5V,

10µA ≤ ISET ≤ 1mA

3

(Note 3)

1mA < ISET ≤ 5mA
2µA ≤ ISET < 10µA

5

8

%

8

12

%

Ratio of Set Current to

100µA ≤ ISET ≤ 1mA

Bias Current

1mA ≤ ISET ≤ 5mA

14

18

23

6

14

14

18

%

26

14

2 µA≤ISET≤100 µA

18

2µA ≤ ISET ≤ 100µA

0.8

0.8

V

100µA < ISET ≤
1mA

0.9...