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 1 dynamic impedance the device operates over a current range of 400 A to 5 mA with virtually no change in performance. When calibrated at 25C the LM135 has typically less than 1C error over a 100C temperature range. Unlike other sensors the LM135 has a linear output. Applications for the LM135 include almost any type of temperature sensing over a -55C to +150C temperature range. The low impedance and linear output make interfacing to readout or control circuitry especially easy. The LM135 operates over a -55C to +150C temperature range while the LM235 operates over a -40C to +125C