LM35
Precision Centigrade Temperature Sensors
General Description
The LM35 series are precision integrated-circuit temperature
sensors, whose output voltage is linearly proportional to the
Celsius (Centigrade) temperature. The LM35 thus has an advantage
over linear temperature sensors calibrated in ˚ Kelvin, as the user
is not required to subtract a large constant voltage from its
output to obtain convenient Centigrade scaling. The LM35 does not
require any external calibration or trimming to provide typical
accuracies of ±1⁄4˚C at room temperature and ±3⁄4˚C over a full −55
to +150˚C temperature range. Low cost is assured by trimming and
calibration at the wafer level. The LM35’s low output impedance,
linear output, and precise inherent calibration make interfacing to
readout or control circuitry especially easy. It can be used with
single power supplies, or with plus and minus supplies. As it draws
only 60 µA from its supply, it has very low self-heating, less than
0.1˚C in still air. The LM35 is rated to operate over a −55˚ to
+150˚C temperature range, while the LM35C is rated for a −40˚ to
+110˚C range (−10˚ with improved accuracy). The LM35 series is
available packaged in hermetic TO-46 transistor packages, while the
LM35C, LM35CA, and LM35D are also available in the plastic TO-92
transistor package. The LM35D is also available in an 8-lead
surface mount small outline package and a plastic TO-220 package.
Features
- Calibrated directly in ˚ Celsius (Centigrade)
- Linear + 10.0 mV/˚C scale factor
- 0.5˚C accuracy guaranteeable (at +25˚C)
- Rated for full −55˚ to +150˚C range
- Suitable for remote applications
- Low cost due to wafer-level trimming
- Operates from 4 to 30 volts
- Less than 60 µA current drain
- Low self-heating, 0.08˚C in still air
- Nonlinearity only ±1⁄4˚C typical
- Low impedance output, 0.1 Ω for 1 mA load
Typical Applications
Connection Diagrams
Absolute Maximum Ratings (Note 10)
If Military/Aerospace specified devices are required, please
contact the National Semiconductor Sales Office/ Distributors for
availability and specifications.
Supply Voltage +35V to −0.2V
Output Voltage +6V to −1.0V
Output Current 10 mA
Storage Temp.;
TO-46 Package, −60˚C to +180˚C
TO-92 Package, −60˚C to +150˚C
SO-8 Package, −65˚C to +150˚C
TO-220 Package, −65˚C to +150˚C
Lead Temp.:
TO-46 Package, (Soldering, 10 seconds) 300˚C
TO-92 and TO-220 Package, (Soldering, 10 seconds) 260˚C
SO Package (Note 12)
Vapor Phase (60 seconds) 215˚C
Infrared (15 seconds) 220˚C
ESD Susceptibility (Note 11) 2500V
Specified Operating Temperature Range: TMIN to TMAX (Note 2)
LM35, LM35A −55˚C to +150˚C
LM35C, LM35CA −40˚C to +110˚C
LM35D 0˚C to +100˚C
