LM135
LM235-LM335,A
PRECISION TEMPERATURE SENSORS
..
..
DIRECTLY CALIBRATED IN oK
1oC INITIAL ACCURACY
OPERATES FROM 450µA TO 5mA
LESS THAN 1Ω DYNAMIC IMPEDANCE
Z
TO92
(Plastic Package
D
SO8
(Plastic Micropackage)
DESCRIPTION
The LM135, LM235, LM335 are precision temperature sensors which can be easily calibrated. They
operate as a 2-terminal Zener and the breakdown
voltage is directly proportional to the absolute temperature at 10mV/oK. The circuit has a dynamic impedance of less than 1Ω and operates within a
range of current from 450µA to 5mA without alteration of its characteristics. Calibrated at +25oC, the
LM135, LM235, LM335 have a typical error of less
than 1oC over a 100oC temperature range. Unlike
other sensors, the LM135, LM235, LM335 have a
linear output.
ORDER CODES
Part number
Temperature
Range
Z
D
o
o
•
•
o
o
•
•
o
o
•
•
LM135
–55 C, +150 C
LM235
–40 C, +125 C
–40 C, +100 C
LM335,A
PIN CONNECTIONS
TO92
(Bottom view)
October 1997
NC
7
NC
6
ADJ
5
1
NC
2
NC
3
NC
4
V
V-
135-02.EPS
V+
135-01.EPS
ADJ
SO8
(Top view)
V+
8
Package
LM135-LM235-LM335,A
SCHEMATIC DIAGRAM
1 V
50kΩ
3 pF
10k Ω
49kΩ
49kΩ
15.6k Ω
1 2pF
60 0Ω
30kΩ
2 AD J
13.8k Ω
2 kΩ
1.1kΩ
3 V
ABSOLUTE MAXIMUM RATINGS
Symbol
IR
IF
Toper
Tstg
Parameter
LM135
LM235
LM335,A
15
10
15
10
15
10
Operating Free-air Temperature Range - (note 1)
Continuous
Intermittent
–55 to +150
+150 to +200
–40 to +125
+125 to +150
–40 to +100
+100 to +125
Storage Temperature Range
–65 to +150
–65 to +150
–65 to +150
Current
Reverse
Forward
Note : 1. Tj ≤ 150 C
o
2/11
Unit
mA
o
C
o
C
LM135-LM235-LM335,A
TEMPERATURE ACCURACY
LM135 - LM235
LM335A
Parameter
LM335
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
2.95
2.98
3.01
2.92
2.98
3.04
1
2
3
5
2
4
6
9
V
Operating Output Voltage
Tcase = +25oC, IR = 1mA
o
Uncalibrated Temperature Error (IR = 1mA)
o
Tcase = +25 C
Tmin. ≤ Tcase ≤ Tmax.
C
o
o
Temperature Error with 25 C Calibration
Tmin. ≤ Tcase ≤ Tmax., IR = 1mA LM135 - LM235
LM335
LM335A
C
1.5
0.5
1
1
2
o
C
Calibrated Error at Extended Temperature
Tcase = Tmax. (intermittent)
Non-linearity (IR = 1mA)
0.5
2
LM135 - LM235
LM335
LM335A
2
0.3
o
C
1
0.3
0.3
1.5
1.5
ELECTRICAL CHARACTERISTICS - (note 1)
LM135 - LM235
Parameter
Max.
Operating output voltage change with current
450µA ≤ IR ≤ 5mA at constant temperature
2.5
10
Dynamic Impedance (IR = 1mA)
0.5
0.6
Ω
Output Voltage Temperature Drift
+10
+10
mV/ C
80
10
1
80
10
1
s
0.2
0.2
Still Air
Air 0.5m/s
Stirred Oil
o
Time Stability (Tcase = +125 C)
Min.
Typ.
Max.
3
14
Unit
Typ.
Time Constant
Min.
LM335,A
mV
o
o
C/kh
Note : 1. Accuracy measurements are made in a well-stirred oil bath. For other conditions, self heating must be considered.
3/11
LM135-LM235-LM335,A
4/11
LM135-LM235-LM335,A
5/11
LM135-LM235-LM335,A
APPLICATION HINTS
Nominally the output is calibrated at 10mV/oK.
There is an easy method of calibrating the device for
higher accuracies (see typical applications).
Precautions should be taken to ensure good sensing accuracy. As in the case ofall temperaturessensors, self heating can decrease accuracy. The
LM135, LM235, LM335 should operate with a low
current, but sufficient to drive the sensor and its calibration circuit to their maximum operating temperature.
The single point calibration works because the output of the LM135, LM235, LM335 is proportional to
the absolute temperature with the extrapolated output of sensor going to 0V at 0oK ( –273.15oC). Errors
in outputvoltage versus temperature are only slope.
Thus a calibration of the slope at one temperature
corrects errors at all temperatures.
where T is the unknown temperature and TO is the
reference temperature (in oK).
If the sensor is used in surroundings where the thermal resistane is constant,the errors due to self heating can be externally calibrated. This is possible if
the circuit is biased with a temperature stable current. Heating will then be proportional to zener voltage and therefore temperature. In this way the error
due to self heating is proportional to the absolute
temperature as scale factor errors.
TYPICAL APPLICATIONS
BASIC TEMPERATURE SENSOR
WIDE OPERATING SUPPLY
The output of the circuit (calibrated or not) can be
T
given by the equation : VOT = VOTO x
To
Vi
+5 to +40V
V
LM134, LM234
LM334
R1
Output
10mV/°K
LM135
LM235
LM335
Output
10mV/°K
LM135
LM235
LM335
CALIBRATED SENSOR
AVERAGE TEMPERATURE SENSING
+15V
V
6kΩ
R1
Output
10mV/°K
LM135
LM235
LM335
* Calibrate for 2.982V at +25oC
6/11
68Ω
10kΩ*
Output
30mV/°K
LM135
LM235
LM335
LM135-LM235-LM335,A
ISOLATED TEMPERATURE SENSOR
LM135
LM235
LM335
+15V
+15V
50kΩ
1N457 0.1µF
m=1
3kΩ
2kΩ
01.µF
3
1kΩ
8
5
LM311
2
4
1
10kΩ
510Ω
6
3
7
LF398
1N4148
1
10kΩ
Output
10mV/°K
5
6
7
8 4
200pF 27kΩ
100kΩ
-15V
1000pF
1N4148 -15V
SIMPLE TEMPERATURE CONTROLLER
+10V to +30V
2kΩ
10kΩ
10kΩ
5kΩ
2
5
6
0.01µF
1N4568
Heater
8
LM311
10kΩ
7
BUV26
4
3
1
4kΩ
LM135
LM235
LM335
7/11
LM135-LM235-LM335,A
CENTIGRADE THERMOMETER
1kΩ
+15V
+15V
+15V
2
6kΩ
12kΩ
7
6
LM308
{
3
8
Output
10mV/°C
4
LM135
LM235
LM335
8.5kΩ
10kΩ
LM136
2kΩ *
100pF
* Adjust for 2.7315V at
output of LM308
DIFFERENTIAL TEMPERATURE SENSOR
+15V
12kΩ
200kΩ
12kΩ
+15V
20kΩ
2
7
6
LM308
20kΩ
8
3
4
180kΩ
LM135
LM235
LM335
8/11
-15V
100pF
50kΩ
Output
100mV/°C
LM135-LM235-LM335,A
THERMOCOUPLE COLD JUNCTION COMPENSATION
(compensation for grounded thermocouple)
+15V
4.7kΩ
Thermocouple
R3
Seebeck
Coefficient
J
T
K
S
377Ω
308Ω
293Ω
45.8Ω
52.3µV/oC
42.8µV/oC
o
40.8µV/ C
o
6.4µV/ C
200kΩ
1%
R2
10
kΩ
1N4568
Adjustments : compensates for both sensor
and resistor tolerances.
1. Short 1N4568.
2. Adjust R1 for SEEBECK coefficient times
ambient temperature (in degrees K) across
R3.
3. Short LM135 and adjust R2 for voltage
across R3 corresponding to thermocouple
type.
J 14.32mV
K 11.17mV
T 11.79mV
S 1.768mV
R3*
1MΩ
1%
R1
10kΩ
LM135
LM235
LM335
12kΩ
Thermocouple
71.5kΩ
1%
-15V
* Select R3 for proper thermocouple type
SINGLE POWER SUPPLY COLD JUNCTION COMPENSATION
+15V
10kΩ
200kΩ
Thermocouple
LM135
LM235
LM335
R1
10kΩ
R3*
+15V
200kΩ
R3
R4
Seebeck
Coefficient
J
T
K
S
1.05kΩ
856Ω
816Ω
128Ω
365Ω
315Ω
300Ω
46.3Ω
52.3µV/oC
42.8µV/ C
o
40.8µV/ C
o
6.4µV/ C
o
Adjustments :
1. Adjust R1 for the voltage across R3 equal
to the SEEBECK coefficient times ambient
temperature in degrees Kelvin.
2. Adjust R2 for voltage across R4 corresponding to thermocouple.
J 14.32mV
K 11.17mV
T 11.79mV
S 1.768mV
Output
1N4568
R2
10
kΩ
Thermocouple
1MΩ
R4*
* Select R3 and R4 for proper thermocouple
9/11
LM135-LM235-LM335,A
PM-SO8.EPS
PACKAGE MECHANICAL DATA
8 PINS - PLASTIC MICROPACKAGE (SO)
A
a1
a2
a3
b
b1
C
c1
D
E
e
e3
F
L
M
S
10/11
Min.
Millimeters
Typ.
0.1
0.65
0.35
0.19
0.25
Max.
1.75
0.25
1.65
0.85
0.48
0.25
0.5
Min.
Inches
Typ.
0.026
0.014
0.007
0.010
Max.
0.069
0.010
0.065
0.033
0.019
0.010
0.020
0.189
0.228
0.197
0.244
0.004
o
45 (typ.)
4.8
5.8
5.0
6.2
1.27
3.81
3.8
0.4
0.050
0.150
4.0
1.27
0.6
0.150
0.016
o
8 (max.)
0.157
0.050
0.024
SO8.TBL
Dimensions
LM135-LM235-LM335,A
PM-TO92.IMG
PACKAGE MECHANICAL DATA
3 PINS - PLASTIC PACKAGE TO92
L
B
O1
C
K
O2
a
Min.
3.2
4.45
4.58
12.7
0.407
0.35
Millimeters
Typ.
1.27
3.7
5.00
5.03
0.5
Max.
Min.
4.2
5.2
5.33
0.126
0.1752
0.1803
0.5
0.016
0.0138
0.508
Inches
Typ.
0.05
0.1457
0.1969
0.198
0.1654
0.2047
0.2098
0.0197
0.02
Max.
TO92TBL
Dimensions
1997 SGS-THOMSON Microelectronics – Printed in Italy – All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco
The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdo m - U.S.A.
11/11
ORDER CODE :
Information furnished is believed to be accurate and reliable. However, SGS-THO MSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which
may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON
Microelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes
and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not author ized for use as critical
componen ts in life support devices or systems without express written approval of SGS-THOMSON Microelectronics.