- Operates from 1V to 40V
- 0.02%/V current regulation
- Programmable from 1μA to 10mA
- True 2-end operation
- Available as a fully specified temperature sensor
- Initial accuracy of ± 3%
illustrate
The LM134/LM234/LM334 are three-terminal adjustable 10,000:1 current sources featuring adjustable operating current, excellent current regulation and wide dynamic voltage range from 1V to 40V. It is currently necessary to build an external resistor, and nowhere else is required. The initial current accuracy is ± 3%. The LM134/LM234/LM334 are true floating, no separate power supply connected to the current source. In addition, reverse voltages up to 20V applications will allow the device to act as a current source in both rectifiers and AC applications with only a few tens of microamps.
The sense voltage used to establish the LM134's operating current of 64mV at 25°C, which is proportional to the absolute temperature (°K). The simplest one is to connect an external resistor, then, to generate a temperature-dependent current with [approximately] 0.33%/°C. Zero drift can be operated by adding an additional resistor and a diode.
Applications for current sources include bias networks, surge protection, low-power references, apron generation, LED drivers, and temperature sensors. The LM234-3 and LM234-6 are designated as true temperature sensors with guaranteed ± 3°C and ±6°C, respectively, initial accuracy. These devices are ideal for remote sensing applications because the long-term running resistance in the series does not affect accuracy. In addition, only 2 lines are required.
The LM134 is guaranteed over a temperature range of -55°C to +125°C, from -25°C to +100°C to LM234°C and from 0 LM334°C to +70°C. These devices are available in TO-46 hermetically sealed, TO-92 and SO-8 plastic packages.
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