LM335A

LM135/LM235/LM335, LM135A/LM235A/LM335A Precision Temperature Sensors May 1999 LM135/LM235/LM335, LM135A/LM235A/LM335A Precision Temperature Sensors General Description The LM135 series are precision, easily-calibrated, integrated circuit temperature sensors. Operating as a 2-terminal zener, the LM135 has a breakdown voltage directly proportional to absolute temperature at +10 mV/˚K. With less than 1Ω dynamic impedance the device operates over a current range of 400 µA to 5 mA with virtually no change in performance. When calibrated at 25˚C the LM135 has typically less than 1˚C error over a 100˚C temperature range. Unlike other sensors the LM135 has a linear output. Applications for the LM135 include almost any type of temperature sensing over a −55˚C to +150˚C temperature range. The low impedance and linear output make interfacing to readout or control circuitry especially easy. The LM135 operates over a −55˚C to +150˚C temperature range while the LM235 operates over a −40˚C to +125˚C temperature range. The LM335 operates from −40˚C to +100˚C. The LM135/LM235/LM335 are available packaged in hermetic TO-46 transistor packages while the LM335 is also available in plastic TO-92 packages. Features n n n n n n n n Directly calibrated in ˚Kelvin 1˚C initial accuracy available Operates from 400 µA to 5 mA Less than 1Ω dynamic impedance Easily calibrated Wide operating temperature range 200˚C overrange Low cost Schematic Diagram DS005698-1 © 1999 National Semiconductor Corpora...