LM34
Precision Fahrenheit Temperature Sensors
General Description
The LM34 series are precision integrated-circuit temperature
sensors, whose output voltage is linearly proportional to the
Fahrenheit temperature. The LM34 thus has an advantage
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 Fahrenheit
scaling. The LM34 does not require any external calibration
or trimming to provide typical accuracies of
1
/
2
F at room
temperature and
1
1
/
2
F over a full -50 to +300F tempera-
ture range. Low cost is assured by trimming and calibration
at the wafer level. The LM34'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 75 A from its supply, it has very low
self-heating, less than 0.2F in still air. The LM34 is rated to
operate over a -50 to +300F temperature range, while the
LM34C is rated for a -40 to +230F range (0F with im-
proved 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 comple-
ment to the LM35 (Centigrade) temperature sensor.
Features
n
Calibrated directly in degrees Fahrenheit
n
Linear +10.0 mV/F scale factor
n
1.0F accuracy guaranteed (at +77F)
n
Rated for full -50 to +300F range
n
Suitable for remote applications
n
Low cost due to wafer-level trimming
n
Operates from 5 to 30 volts
n
Less than 90 A current drain
n
Low self-heating, 0.18F in still air
n
Nonlinearity only
0.5F typical
n
Low-impedance output, 0.4
for 1 mA load
Connection Diagrams
Note 1: Case is connected to negative pin (GND).
TRI-STATE
is a registered trademark of National Semiconductor Corporation.
TO-46
Metal Can Package
(Note 1)
DS006685-1
Order Numbers LM34H,
LM34AH, LM34CH,
LM34CAH or LM34DH
See NS Package
Number H03H
TO-92
Plastic Package
DS006685-2
Order Number LM34CZ,
LM34CAZ or LM34DZ
See NS Package
Number Z03A
SO-8
Small Outline
Molded Package
DS006685-20
N.C. = No Connection
Top View
Order Number LM34DM
See NS Package Number M08A
July 1999
LM34
Precision
Fahrenheit
T
emperature
Sensors
1999 National Semiconductor Corporation
DS006685
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Typical Applications
DS006685-3
FIGURE 1. Basic Fahrenheit Temperature Sensor
(+5 to +300F)
DS006685-4
FIGURE 2. Full-Range Fahrenheit Temperature Sensor
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2
Absolute Maximum Ratings
(Note 11)
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 Temperature,
TO-46 Package
-76F to +356F
TO-92 Package
-76F to +300F
SO-8 Package
-65C to +150C
ESD Susceptibility (Note 12)
800V
Lead Temp.
TO-46 Package
(Soldering, 10 seconds)
+300C
TO-92 Package
(Soldering, 10 seconds)
+260C
SO Package (Note 13)
Vapor Phase (60 seconds)
215C
Infrared (15 seconds)
220C
Specified Operating Temp. Range (Note 3)
T
MIN
to T
MAX
LM34, LM34A
-50F to +300F
LM34C, LM34CA
-40F to +230F
LM34D
+32F to +212F
DC Electrical Characteristics
(Notes 2, 7)
LM34A
LM34CA
Parameter
Conditions
Tested
Design
Tested
Design
Units
Typical
Limit
Limit
Typical
Limit
Limit
(Max)
(Note 5)
(Note 6)
(Note 5)
(Note 6)
Accuracy (Note 8)
T
A
= +77F
0.4
1.0
0.4
1.0
F
T
A
= 0F
0.6
0.6
2.0
F
T
A
= T
MAX
0.8
2.0
0.8
2.0
F
T
A
= T
MIN
0.8
2.0
0.8
3.0
F
Nonlinearity (Note 9)
T
MIN
T
A
T
MAX
0.35
0.7
0.30
0.6
F
Sensor Gain
T
MIN
T
A
T
MAX
+10.0
+9.9,
+10.0
+9.9,
mV/F, min
(Average Slope)
+10.1
+10.1
mV/F, max
Load Regulation
T
A
= +77F
0.4
1.0
0.4
1.0
mV/mA
(Note 4)
T
MIN
T
A
T
MAX
0.5
3.0
0.5
3.0
mV/mA
0
I
L
1 mA
Line Regulation
T
A
= +77F
0.01
0.05
0.01
0.05
mV/V
(Note 4)
5V
V
S
30V
0.02
0.1
0.02
0.1
mV/V
Quiescent Current
V
S
= +5V, +77F
75
90
75
90
A
(Note 10)
V
S
= +5V
131
160
116
139
A
V
S
= +30V, +77F
76
92
76
92
A
V
S
= +30V
132
163
117
142
A
Change of Quiescent
4V
V
S
30V, +77F
+0.5
2.0
0.5
2.0
A
Current (Note 4)
5V
V
S
30V
+1.0
3.0
1.0
3.0
A
Temperature Coefficient
+0.30
+0.5
+0.30
+0.5
A/F
of Quiescent Current
Minimum Temperature
In circuit of
Figure 1,
+3.0
+5.0
+3.0
+5.0
F
for Rated Accuracy
I
L
= 0
Long-Term Stability
T
j
= T
MAX
for 1000 hours
0.16
0.16
F
Note 2: Unless otherwise noted, these specifications apply: -50F
T
j
+ 300F for the LM34 and LM34A; -40F
T
j
+230F for the LM34C and LM34CA; and
+32F
T
j
+ 212F for the LM34D. V
S
= +5 Vdc and I
LOAD
= 50 A in the circuit of Figure 2; +6 Vdc for LM34 and LM34A for 230F
T
j
300F. These specifications
also apply from +5F to T
MAX
in the circuit of
Figure 1.
Note 3: Thermal resistance of the TO-46 package is 720F/W junction to ambient and 43F/W junction to case. Thermal resistance of the TO-92 package is 324F/W
junction to ambient. Thermal resistance of the small outline molded package is 400F/W junction to ambient. For additional thermal resistance information see table
in the Typical Applications section.
Note 4: Regulation is measured at constant junction temperature using pulse testing with a low duty cycle. Changes in output due to heating effects can be computed
by multiplying the internal dissipation by the thermal resistance.
Note 5: Tested limits are guaranteed and 100% tested in production.
Note 6: Design limits are guaranteed (but not 100% production tested) over the indicated temperature and supply voltage ranges. These limits are not used to cal-
culate outgoing quality levels.
Note 7: Specification in BOLDFACE TYPE apply over the full rated temperature range.
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3
DC Electrical Characteristics
(Notes 2, 7) (Continued)
Note 8: Accuracy is defined as the error between the output voltage and 10 mV/F times the device's case temperature at specified conditions of voltage, current,
and temperature (expressed in F).
Note 9: Nonlinearity is defined as the deviation of the output-voltage-versus-temperature curve from the best-fit straight line over the device's rated temperature
range.
Note 10: Quiescent current is defined in the circuit of
Figure 1.
Note 11: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating
the device beyond its rated operating conditions (Note 2).
Note 12: Human body model, 100 pF discharged through a 1.5 k
resistor.
Note 13: See AN-450 "Surface Mounting Methods and Their Effect on Product Reliability" or the section titled "Surface Mount" found in a current National Semicon-
ductor Linear Data Book for other methods of soldering surface mount devices.
DC Electrical Characteristics
(Notes 2, 7)
LM34
LM34C, LM34D
Parameter
Conditions
Tested
Design
Tested
Design
Units
Typical
Limit
Limit
Typical
Limit
Limit
(Max)
(Note 5)
(Note 6)
(Note 5)
(Note 6)
Accuracy, LM34, LM34C
T
A
= +77F
0.8
2.0
0.8
2.0
F
(Note 8)
T
A
= 0F
1.0
1.0
3.0
F
T
A
= T
MAX
1.6
3.0
1.6
3.0
F
T
A
= T
MIN
1.6
3.0
1.6
4.0
F
Accuracy, LM34D
T
A
= +77F
1.2
3.0
F
(Note 8)
T
A
= T
MAX
1.8
4.0
F
T
A
= T
MIN
1.8
4.0
F
Nonlinearity (Note 9)
T
MIN
T
A
T
MAX
0.6
1.0
0.4
1.0
F
Sensor Gain
T
MIN
T
A
T
MAX
+10.0
+9.8,
+10.0
+9.8,
mV/F, min
(Average Slope)
+10.2
+10.2
mV/F, max
Load Regulation
T
A
= +77F
0.4
2.5
0.4
2.5
mV/mA
(Note 4)
T
MIN
T
A
+150F
0.5
6.0
0.5
6.0
mV/mA
0
I
L
1 mA
Line Regulation
T
A
= +77F
0.01
0.1
0.01
0.1
mV/V
(Note 4)
5V
V
S
30V
0.02
0.2
0.02
0.2
mV/V
Quiescent Current
V
S
= +5V, +77F
75
100
75
100
A
(Note 10)
V
S
= +5V
131
176
116
154
A
V
S
= +30V, +77F
76
103
76
103
A
V
S
= +30V
132
181
117
159
A
Change of Quiescent
4V
V
S
30V, +77F
+0.5
3.0
0.5
3.0
A
Current (Note 4)
5V
V
S
30V
+1.0
5.0
1.0
5.0
A
Temperature Coefficient
+0.30
+0.7
+0.30
+0.7
A/F
of Quiescent Current
Minimum Temperature
In circuit of
Figure 1,
+3.0
+5.0
+3.0
+5.0
F
for Rated Accuracy
I
L
= 0
Long-Term Stability
T
j
= T
MAX
for 1000 hours
0.16
0.16
F
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4
Typical Performance Characteristics
Thermal Resistance
Junction to Air
DS006685-22
Thermal Time Constant
DS006685-23
Thermal Response in
Still Air
DS006685-24
Thermal Response in
Stirred Oil Bath
DS006685-25
Minimum Supply Voltage
vs. Temperature
DS006685-26
Quiescent Current vs.
Temperature
(In Circuit of
Figure 1)
DS006685-27
Quiescent Current vs. Temp-
erature (In Circuit of
Figure 2;
-V
S
= -5V, R1 = 100k)
DS006685-28
Accuracy vs. Temperature
(Guaranteed)
DS006685-29
Accuracy vs. Temperature
(Guaranteed)
DS006685-30
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