SNIS159C – AUGUST 1999 – REVISED JULY 2013
LM35 Precision Centigrade Temperature Sensors
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FEATURES
Calibrated Directly in ° Celsius (Centigrade)
Linear + 10 mV/°C Scale Factor
0.5°C Ensured Accuracy (at +25°C)
Rated for Full
−55°C
to +150°C Range
Suitable for Remote Applications
Low Cost Due to Wafer-Level Trimming
Operates from 4 to 30 V
Less than 60-μA Current Drain
Low Self-Heating, 0.08°C in Still Air
Nonlinearity Only ±¼°C Typical
Low Impedance Output, 0.1 W for 1 mA Load
DESCRIPTION
The LM35 series are precision integrated-circuit
temperature sensors, with an output voltage linearly
proportional to the Centigrade temperature. Thus the
LM35 has an advantage over linear temperature
sensors calibrated in ° Kelvin, as the user is not
required to subtract a large constant voltage from the
output to obtain convenient Centigrade scaling. The
LM35 does not require any external calibration or
trimming to provide typical accuracies of ±¼°C at
room temperature and ±¾°C over a full
−55°C
to
+150°C temperature range. Low cost is assured by
trimming and calibration at the wafer level. The low
output impedance, linear output, and precise inherent
calibration of the LM35 make interfacing to readout or
control circuitry especially easy. The device is used
with single power supplies, or with plus and minus
supplies. As the LM35 draws only 60
μA
from the
supply, it has very low self-heating of less than 0.1°C
in still air. The LM35 is rated to operate over a
−55°C
to +150°C temperature range, while the LM35C is
rated for a
−40°C
to +110°C range (−10° with
improved accuracy). The LM35 series is available
packaged in hermetic TO 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.
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+V
S
(4 V to 20 V)
+V
S
LM35
OUTPUT
0 mV + 10.0 mV/°C
LM35
V
OUT
R1
Figure 1. Basic Centigrade Temperature Sensor
(+2°C to +150°C)
tV
S
Choose R
1
= –V
S
/ 50 µA
V
OUT
= 1500 mV at 150°C
V
OUT
= 250 mV at 25°C
V
OUT
= –550 mV at –55°C
Figure 2. Full-Range Centigrade Temperature
Sensor
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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Copyright © 1999–2013, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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