1 Features

• Directly Calibrated to the Kelvin Temperature Scale
• 1°C Initial Accuracy Available
• Operates from 400 μA to 5 mA
• Less than 1-Ω Dynamic Impedance
• Easily Calibrated
• Wide Operating Temperature Range
• 200°C Overrange
• Low Cost

2 Applications

• Power Supplies
• Battery Management
• HVAC
• Appliances

3 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 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 TO-92 packages.

1. For all available packages, see the orderable addendum at the end of the datasheet.

Basic Temperature Sensor Simplified Schematic

Calibrated Sensor