LM50 SOT-23 Single-Supply Centigrade Temperature Sensor
July 1999
LM50
SOT-23 Single-Supply Centigrade Temperature Sensor
General Description
The LM50 is a precision integrated-circuit temperature sen-
sor that can sense a −40˚C to +125˚C temperature range us-
ing a single positive supply. The LM50’s output voltage is lin-
early proportional to Celsius (Centigrade) temperature
(+10 mV/˚C) and has a DC offset of +500 mV. The offset al-
lows reading negative temperatures without the need for a
negative supply. The ideal output voltage of the LM50 ranges
from +100 mV to +1.75V for a −40˚C to +125˚C temperature
range. The LM50 does not require any external calibration or
trimming to provide accuracies of
±
3˚C at room temperature
and
±
4˚C over the full −40˚C to +125˚C temperature range.
Trimming and calibration of the LM50 at the wafer level as-
sure low cost and high accuracy. The LM50’s linear output,
+500 mV offset, and factory calibration simplify circuitry re-
quired in a single supply environment where reading nega-
tive temperatures is required. Because the LM50’s quiescent
current is less than 130 µA, self-heating is limited to a very
low 0.2˚C in still air.
Applications
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Computers
Disk Drives
Battery Management
Automotive
FAX Machines
Printers
Portable Medical Instruments
HVAC
Power Supply Modules
Features
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Calibrated directly in degree Celsius (Centigrade)
Linear + 10.0 mV/˚C scale factor
±
2˚C accuracy guaranteed at +25˚C
Specified for full −40˚ to +125˚C range
Suitable for remote applications
Low cost due to wafer-level trimming
Operates from 4.5V to 10V
Less than 130 µA current drain
Low self-heating, less than 0.2˚C in still air
Nonlinearity less than 0.8˚C over temp
Connection Diagram
SOT-23
Order
Number
LM50BIM3
LM50CIM3
DS012030-1
SOT-23
Device Marking
T5B
T5C
T5B
T5C
Supplied As
1000 Units on Tape
and Reel
1000 Units on Tape
and Reel
3000 Units on Tape
and Reel
3000 Units on Tape
and Reel
LM50BIM3X
LM50CIM3X
Top View
See NS Package Number MA03B
Typical Application
DS012030-3
FIGURE 1. Full-Range Centigrade Temperature Sensor (−40˚C to +125˚C)
© 1999 National Semiconductor Corporation
DS012030
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
