March 2000
LM134/LM234/LM334
3-Terminal Adjustable Current Sources
LED driver, and temperature sensing. The LM234-3 and
LM234-6 are specified as true temperature sensors with
General Description
The LM134/LM234/LM334 are 3-terminal adjustable current
sources featuring 10,000:1 range in operating current, excel-
lent 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
±
±
guaranteed initial accuracy of 3˚C and 6˚C, respectively.
These devices are ideal in remote sense applications be-
cause series resistance in long wire runs does not affect ac-
curacy. 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˚C to +70˚C. These devices are available in
TO-46 hermetic, TO-92 and SO-8 plastic packages.
±
3%. The LM134/LM234/LM334 are true floating current
sources with no separate power supply connections. In addi-
tion, 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.
Features
n Operates from 1V to 40V
n 0.02%/V current regulation
n Programmable from 1µA to 10mA
n True 2-terminal operation
The sense voltage used to establish operating current in the
LM134 is 64mV at 25˚C and is directly proportional to abso-
lute temperature (˚K). The simplest one external resistor
connection, then, generates a current with ≈+0.33%/˚C tem-
perature dependence. Zero drift operation can be obtained
by adding one extra resistor and a diode.
n Available as fully specified temperature sensor
Applications for the current sources include bias networks,
surge protection, low power reference, ramp generation,
±
n
3% initial accuracy
Connection Diagrams
SO-8
Surface Mount Package
SO-8 Alternative Pinout
Surface Mount Package
TO-46
Metal Can Package
DS005697-12
DS005697-24
DS005697-25
−
V
Pin is electrically connected to case.
Order Number LM334M or
LM334MX
See NS Package Number M08A
Order Number LM334SM or
LM334SMX
See NS Package Number M08A
Bottom View
Order Number LM134H,
LM234H or LM334H
See NS Package
Number H03H
TO-92 Plastic Package
DS005697-10
Bottom View
Order Number LM334Z, LM234Z-3 or LM234Z-6
See NS Package Number Z03A
© 2000 National Semiconductor Corporation
DS005697
www.national.com