LM135/LM235/LM335, LM135A/LM235A/LM335A Precision Temperature Sensors
November 2000
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/藲K. With less than 1鈩?dy-
namic impedance the device operates over a current range
of 400 碌A to 5 mA with virtually no change in performance.
When calibrated at 25藲C the LM135 has typically less than
1藲C error over a 100藲C temperature range. Unlike other
sensors the LM135 has a linear output.
Applications for the LM135 include almost any type of tem-
perature sensing over a 鈭?5藲C to +150藲C temperature
range. The low impedance and linear output make interfac-
ing to readout or control circuitry especially easy.
The LM135 operates over a 鈭?5藲C to +150藲C temperature
range while the LM235 operates over a 鈭?0藲C to +125藲C
temperature range. The LM335 operates from 鈭?0藲C to
+100藲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 藲Kelvin
1藲C initial accuracy available
Operates from 400 碌A to 5 mA
Less than 1鈩?dynamic impedance
Easily calibrated
Wide operating temperature range
200藲C overrange
Low cost
Schematic Diagram
DS005698-1
漏 2000 National Semiconductor Corporation
DS005698
www.national.com