data/text/DLP1/899395

LM134: Temperature stabilized current source

Part Number: LM134 Hi sir, I'm looking for a constant current source with the following properties: - output current ideally in the 50mA range, but 10mA could work too - the precision doesn't matter so much (100ppm is plenty), but it's more important for the current to be stable over temperature - operational temperature up to 125C The application is in-circuit temperature sensing by measuring changes to the resistance of copper. The current source drives some long, intentional copper traces and we measure the voltage across the long trace. I'm looking for something that can deliver a relatively stable current over a wide temperature range. The LM134 has an output current drift of 0.3%/C, or equivalently 3000ppm/C. I'm interested in something that's closer to the 3 or 30ppm/C range, so that the total fluctuation between 25C and 125C is ~3000ppm. Thank u. Regards,

Are you open to using a discrete solution? The LM4051-N is a high precision voltage reference that can be configured to be a current source as per fig 29 on the DS. This can achieve a higher precision than the LM134. The total temperature fluctuation of the LM4051-N is around 3300ppm.

Great helpful, thank u so much.