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-Ω 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 are 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 LMx35 devices are available packaged in hermetic TO transistor packages while the LM335 is also available in plastic