TMP35FSZ Analog Devices Inc, TMP35FSZ Datasheet - Page 11

• Manufacturer Part Number: TMP35FSZ
• Description: IC SENSOR TEMP 2.7/5.5V 8SOIC
• Manufacturer: Analog Devices Inc

Specifications of TMP35FSZ

• Sensing Temperature: 10°C ~ 125°C
• Output Type: Voltage
• Voltage - Supply: 2.7 V ~ 5.5 V
• Accuracy: ±1°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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.
10µF/0.1µF
0.1µF
Figure 26. TMP36 Fahrenheit Thermometer Version 1
+
TMP36
+V
TMP36
S
+V
GND
S
GND
+V
V
S
ELEMENT
OUT
V
R3
R4
R5
R6
OUT
50kΩ
50kΩ
V
V
R2
OUT
OUT
R1
@ –40°F = 18mV
@ +257°F = 315mV
R2
10kΩ
R1
45.3kΩ
258.6kΩ
10kΩ
47.7kΩ
10kΩ
VALUE
V
+3V
OUT
Figure 27. TMP36 Fahrenheit Thermometer Version 2
@ 1mV/°F
10µF
C1
–
10µF
+
58°F
NC
+
Rev. F | Page 11 of 20
1
2
4
3
R3
R5
ADM660
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
8
V
R6
OUT
=
5
6
7
⎛
⎜
⎜
⎝
R5
3
2
R6
+
–
+
OP193
R6
7
4
+
⎞
⎟
⎟
⎠
–3V
10µF
⎛
⎜
⎜
⎝
NC
0.1µF
1
R4
+
6
R3
R4
TMP35/TMP36/TMP37
⎞
⎟
⎟
⎠
(
TMP36
)
−
⎛
⎜
⎝
R4
R3
V
–40°F ≤ T
OUT
⎞
⎟
⎠
⎛
⎜
⎝
@ 1mV/°F
V
2
S
A
⎞
⎟
⎠
≤ +257°F