LM34 LM34A LM34C LM34CA LM34D Precision Fahrenheit Temperature Sensors
December 1994
LM34 LM34A LM34C LM34CA LM34D
Precision Fahrenheit Temperature Sensors
General Description
The LM34 series are precision integrated-circuit tempera-
ture sensors whose output voltage is linearly proportional to
the Fahrenheit temperature The LM34 thus has an advan-
tage over linear temperature sensors calibrated in degrees
Kelvin as the user is not required to subtract a large con-
stant voltage from its output to obtain convenient Fahren-
heit scaling The LM34 does not require any external cali-
bration or trimming to provide typical accuracies of
g
F at
room temperature and
g
1 F over a full
b
50 to
a
300 F
temperature range Low cost is assured by trimming and
calibration at the wafer level The LM34’s low output imped-
ance 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 75
mA
from its supply it has
very low self-heating less than 0 2 F in still air The LM34 is
rated to operate over a
b
50 to
a
300 F temperature
range while the LM34C is rated for a
b
40 to
a
230 F
range (0 F with improved accuracy) The LM34 series is
available packaged in hermetic TO-46 transistor packages
while the LM34C LM34CA and LM34D are also available in
the plastic TO-92 transistor package The LM34D is also
available in an 8-lead surface mount small outline package
The LM34 is a complement to the LM35 (Centigrade) tem-
perature sensor
Features
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Calibrated directly in degrees Fahrenheit
Linear
a
10 0 mV F scale factor
1 0 F accuracy guaranteed (at
a
77 F)
Rated for full
b
50 to
a
300 F range
Suitable for remote applications
Low cost due to wafer-level trimming
Operates from 5 to 30 volts
Less than 90
mA
current drain
Low self-heating 0 18 F in still air
Nonlinearity only
g
0 5 F typical
Low-impedance output 0 4X for 1 mA load
Connection Diagrams
TO-46
Metal Can Package
TO-92
Plastic Package
SO-8
Small Outline Molded Package
TL H 6685 –1
TL H 6685 – 2
Case is connected to negative pin (GND)
Order Numbers LM34H LM34AH
LM34CH LM34CAH or LM34DH
See NS Package Number H03H
Order Number LM34CZ
LM34CAZ or LM34DZ
See NS Package Number Z03A
TL H 6685 – 20
Top View
N C
e
No Connection
Order Number LM34DM
See NS Package Number M08A
Typical Applications
TL H 6685 – 3
FIGURE 1 Basic Fahrenheit Temperature Sensor
(
a
5 to
a
300 F)
TL H 6685 – 4
TRI-STATE is a registered trademark of National Semiconductor Corporation
C
1995 National Semiconductor Corporation
TL H 6685
FIGURE 2 Full-Range Fahrenheit Temperature Sensor
RRD-B30M75 Printed in U S A
NSC [ NATIONAL SEMICONDUCTOR ]
