LM234

If Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
V+ to V− Forward Voltage
LM134/LM234/LM334 .........................40V
LM234-3/LM234-6 ..............................30V
V+ to V− Reverse Voltage....................... 20V
R Pin to V− Voltage ...................................5V
Set Current .........................................10 mA
Power Dissipation .............................400 mW
ESD Susceptibility (Note 6) ..................2000V
Operating Temperature Range (Note 5)
LM134................................. −55°C to +125°C
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-46 Package (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.

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%. The LM134/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 to absolute 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 LM234-6 are 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°C to +70°C. These devices are available in TO-46 hermetic, TO-92 and SO-8 plastic packages.