ST LM135, LM235, LM335 User Manual
Features
■ Directly calibrated in °K
■ 1°C initial accuracy
■ Operates from 450µA to 5mA
■ Less than 1Ω dynamic impedance
Description
LM135-LM235-LM335
Precision temperature sensors
TO-92
(Plastic package)
The LM135, LM235, LM335 are precision
temperature sensors which can be easily
calibrated. They operat e as a 2-terminal Zener
and the breakdown volta ge is directly proportional
to the absolute temperature at 10mV/°K.
The circuit has a dynamic impedance of le ss 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 o v er a
100°C temperature range. Unlike other sensors,
the LM135, LM235, LM335 have a linear output.
SO-8
(Plastic micropackage)
Pin connections
TO-92
(Bottom view)
v+
v-
ADJ
SO-8
(Top view)
V+ NC
8765
NC
ADJ
1234
NC
NC
-
NC
V
February 2008 Rev 3 1/16
www.st.com
16
Schematic diagram LM135-LM235-LM335
1 Schematic diagram
Figure 1. Schematic diagram
2 Absolute maximum ratings
Table 1. Absolute maximum ratings (AMR)
Symbol Parameter LM135 LM235
Current
I
R
I
F
T
oper
T
stg
1. Tj ≤ 150°C
2/16
Reverse
Forward
Operating free-air temperature
(1)
range
Continuous
Intermittent
Storage temperature range -65 to +150 °C
-55 to +150
+150 to +200
15
10
-40 to +125
+125 to +150
LM335-
LM335A
-40 to +100
+100 to +125
Unit
mA
°C
LM135-LM235-LM335 Temperature accuracy
3 Temperature accuracy
Table 2. Temperature accuracy
Parameter
Operating output voltage
= +25°C, IR = 1mA
T
case
Uncalibrated temperature error (I
T
= +25°C
case
≤ T
T
min
case
≤ T
max
= 1mA)
R
Temperature error with 25°C calibration
T
≤ T
≤ T
, IR = 1mA
min
case
max
.
LM135 - LM235
LM335
LM335A
Calibrated error at extended temperature
= T
T
case
Non-linearity (I
(intermittent)
max
= 1mA)
R
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
2
0.5
3
5
1.5
4
5
6
9
12
0.5
1
22°C
0.3
1
0.3 1.5
0.3
1.5
°C
°C
°C
4 Electrical characteristics
Table 3. Electrical characteristics
Operating output voltage change with current
450µA ≤ I
Dynamic impedance (I
Output voltage temperature drift +10 +10 mV/°C
Time constant
Still air
Air 0.5m/s
Stirred oil
Time stability (T
Note: Accuracy measurements are made in a well-stirred oil bath. For other conditions, self-
LM135 - LM235 LM335-LM335A
Parameter
Min. Typ. Max. Min. Typ. Max.
≤ 5mA at constant temperature 2.5 10 3 14 mV
R
= 1mA) 0.5 0.6 Ω
R
80
10
1
= +125°C) 0.2 0.2 °C/kh
case
80
10
1
heating must be considered
Unit
s
3/16
Electrical characteristics LM135-LM235-LM335
Figure 2. Reverse voltage change Figure 3. Calibrated error
Calibrated error (°C)
Reverse voltage change (mV)
Reverse current (mA)
Temperature (°C)
Figure 4. Reverse characteristics Figure 5. Response time
Reverse current (mA)
Voltage swing (V)
Reverse voltage (V)
Time (µs)
Figure 6. Dynamic impedance Figure 7. Noise voltage
Noise (nV/√Hz)
Dynamic impedance (Ohm)
Frequency (Hz)
Frequency (Hz)
4/16
LM135-LM235-LM335 Electrical characteristics
Figure 8. Thermal resistance junction to air Figure 9. Thermal time constant
Time constant (s)
Thermal resistance (°C/W)
Air velocity (m/s)
Air velocity (m/s)
Figure 10. Thermal response in still air Figure 11. Thermal response in stirred oil bath
Percent of final value (%)
Time (min)
Figure 12. Forward characteristics
Forward voltage (V)
Forward current (mA)
Percent of final value (%)
Time (s)
5/16
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