Datasheet

Data Sheet TMP35/TMP36/TMP37
The same circuit principles can be applied to the TMP36, but
because of the inherent offset of the TMP36, the circuit uses only
two resistors, as shown in Figure 26. In this circuit, the output
voltage transfer characteristic is 1 mV/°F but is referenced to
the common ground of the circuit; however, there is a 58 mV
(58°F) offset in the output voltage. For example, the output
voltage of the circuit reads 18 mV if the TMP36 is placed in a
−40°F ambient environment and 315 mV at +257°F.
TMP36
GND
0.1µF
V
OUT
+V
S
R1
45.3kΩ
R2
10kΩ
+V
S
V
OUT
@ –40°F = 18mV
V
OUT
@ +257°F = 315mV
00337-024
V
OUT
@ 1mV/°F – 58°F
Figure 26. TMP36 Fahrenheit Thermometer Version 1
At the expense of additional circuitry, the offset produced by
the circuit in Figure 26 can be avoided by using the circuit in
Figure 27. In this circuit, the output of the TMP36 is conditioned
by a single-supply, micropower op amp, the OP193. Although
the entire circuit operates from a single 3 V supply, the output
voltage of the circuit reads the temperature directly, with a
transfer characteristic of 1 mV/°F, without offset. This is accom-
plished through an ADM660, which is a supply voltage inverter.
The 3 V supply is inverted and applied to the V− terminal of the
OP193. Thus, for a temperature range between −40°F and +257°F,
the output of the circuit reads −40 mV to +257 mV. A general
expression for the transfer equation of the circuit is given by
( )












−








+








+
=
2
1
S
OUT
V
R3
R4
TMP36
R3
R4
R6R5
R6
V
ELEMENT
R3
R4
R5
R6
VALUE
V
OUT
R1
50kΩ
+V
S
ADM660
TMP36
OP193
R2
50kΩ
R3
R4
+3V
C1
10µF
R5
0.1µF
10µF
–3V
10µF/0.1µF
GND
NC
10µF
NC
R6
1
2
3
4
5
6
7
2
3
4
6
7
8
258.6kΩ
10kΩ
47.7kΩ
10kΩ
+
+
+
+
–
+
V
OUT
@ 1mV/°F
–40°F ≤ T
A
≤ +257°F
00337-025
Figure 27. TMP36 Fahrenheit Thermometer Version 2
Rev. H | Page 11 of 19
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.