Document
LM135-LM235-LM335
Precision temperature sensors
Features
■ Directly calibrated in °K ■ 1°C initial accuracy ■ Operates from 450µA to 5mA ■ Less than 1Ω dynamic impedance
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/°K.
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 +25°C, the LM135, LM235, and LM335 have a typical error of less than 1°C over a 100°C temperature range. Unlike other sensors, the LM135, LM235, LM335 have a linear output.
TO-92 (Plastic package)
SO-8 (Plastic micropackage)
Pin connections
TO-92 (Bottom view)
ADJ v+ v-
SO-8 (Top view)
V+
NC
NC ADJ
8
7
6
5
1
2
3
NC NC
NC
4 V
-
February 2008
Rev 3
1/16
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16
Schematic diagram
1
Schematic diagram
Figure 1. Schematic diagram
LM135-LM235-LM335
2
Absolute maximum ratings
Table 1. Absolute maximum ratings (AMR)
Symbol
Parameter
LM135
LM235
LM335LM335A
Unit
Current
IR IF
Reverse Forward
Toper
Operating free-air temperature range(1)
Continuous Intermittent
Tstg Storage temperature range
1. Tj ≤ 150°C
15
mA
10
°C -55 to +150 -40 to +125 -40 to +100 +150 to +200 +125 to +150 +100 to +125
-65 to +150
°C
2/16
LM135-LM235-LM335
3
Temperature accuracy
Temperature accuracy
Table 2. Temperature accuracy
Parameter
Operating output voltage Tcase = +25°C, IR = 1mA Uncalibrated temperature error (IR = 1mA)
Tcase = +25°C Tmin ≤ Tcase ≤ Tmax Temperature error with 25°C calibration Tmin ≤ Tcase ≤ Tmax., IR = 1mA LM135 - LM235 LM335 LM335A
Calibrated error at extended temperature Tcase = Tmax (intermittent) Non-linearity (IR = 1mA)
LM135 - LM235 LM335 LM335A
LM135 - LM235 LM335A
LM335 Unit
Min. Typ. Max. Min. Typ. Max.
2.95 2.98 3.01 2.92 2.98 3.04 V
1
3
2
5
4
6
°C
5
9
0.5 1.5
0.5
1
2
0.3
1
0.3 1.5
°C
1
2
2
°C
°C 0.3 1.5
4
Electrical characteristics
Table 3. Electrical characteristics Parameter
LM135 - LM235
LM335-LM335A
Unit
Min. Typ. Max. Min. Typ. Max.
Operating output voltage change with current 450µA ≤ IR ≤ 5mA at constant temperature
Dynamic impedance (IR = 1mA) Output voltage temperature drift
Time constant Still air Air 0.5m/s Stirred oil
Time stability (Tcase = +125°C)
2.5 10 0.5 +10
80 10 1 0.2
3
14 mV
0.6
Ω
+10
mV/°C
80
s
10
1
0.2
°C/kh
Note:
Accuracy measurements are made in a well-stirred oil bath. For other conditions, selfheating must be considered
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Electrical characteristics Figure 2. Reverse voltage change
LM135-LM235-LM335 Figure 3. Calibrated error
Calibrated error (°C)
Reverse voltage change (mV)
Reverse current (mA) Figure 4. Reverse characteristics
Temperature (°C) Figure 5. Response time
Voltage swing (V)
Reverse current (mA)
Reverse voltage (V) Figure 6. Dynamic impedanc.