Rainbow Electronics LM50 - Manual

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
n Computers
n Disk Drives
n Battery Management
n Automotive
n FAX Machines
n Printers
n Portable Medical Instruments
n HVAC
n Power Supply Modules
Features
n Calibrated directly in degree Celsius (Centigrade)
n Linear + 10.0 mV/˚C scale factor
n ± 2˚C accuracy guaranteed at +25˚C
n Specified for full −40˚ to +125˚C range
n Suitable for remote applications
n Low cost due to wafer-level trimming
n Operates from 4.5V to 10V
n Less than 130 µA current drain
n Low self-heating, less than 0.2˚C in still air
n Nonlinearity less than 0.8˚C over temp
Connection Diagram
Order SOT-23 Supplied As
Number Device Marking
LM50BIM3 T5B 1000 Units on Tape
and Reel
LM50CIM3 T5C 1000 Units on Tape
and Reel
LM50BIM3X T5B 3000 Units on Tape
and Reel
LM50CIM3X T5C 3000 Units on Tape
and Reel
Typical Application
SOT-23
DS012030-1
Top View
See NS Package Number MA03B
DS012030-3
FIGURE 1. Full-Range Centigrade Temperature Sensor (−40˚C to +125˚C)
July 1999
LM50
SOT-23
Single-Supply
Centigrade
T
emperature
Sensor
© 1999 National Semiconductor Corporation DS012030 www.national.com