TMP35FSZ Analog Devices Inc, TMP35FSZ Datasheet - Page 16

• 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

TMP35/TMP36/TMP37
TEMPERATURE-TO-FREQUENCY CONVERTER
Another common method of transmitting analog information
from a remote location is to convert a voltage to an equivalent
value in the frequency domain. This is readily done with any of
the low cost, monolithic voltage-to-frequency converters (VFCs)
available. These VFCs feature a robust, open-collector output
transistor for easy interfacing to digital circuitry. The digital
signal produced by the VFC is less susceptible to contamination
from external noise sources and line voltage drops because the
only important information is the frequency of the digital sig-
nal. When the conversions between temperature and frequency
are done accurately, the temperature data from the sensors can
be reliably transmitted.
The circuit in Figure 34 illustrates a method by which the
outputs of these temperature sensors can be converted to a
frequency using the AD654. The output signal of the AD654 is
a square wave that is proportional to the dc input voltage across
Pin 4 and Pin 3. The transfer equation of the circuit is given by
f
OUT
=
⎛
⎜
⎜
⎝
V
10
TPM
×
(
−
R
T
V
OFFSET
×
C
NOTE:
TMP3x
T
1
)
SEE TEXT FOR VALUES.
+V
GND
⎞
⎟
⎟
⎠
S
V
OUT
R1
1
ADJUST
20mA
P1
R3
Figure 33. Temperature to 4–20 mA Loop Transmitter
1
1
R2
P2
4mA
ADJUST
1
1
D1
D1: HP5082-2810
Rev. F | Page 16 of 20
2
3
R4
–
+
1
OP193
7
4
3V
+
1µF
6
0.1µF
6
10µF/0.1µF
REF193
R5
100kΩ
4
100kΩ
R6
2
100Ω
Figure 34. Temperature-to-Frequency Converter
R7
100kΩ
Q1
2N1711
TMP3x
I
L
P2
5V
SENSOR
TMP35
TMP36
TMP37
5V
+V
GND
S
R
R
T
470Ω
1
OFF1
V
OUT
R
11.8kΩ + 500Ω
16.2kΩ + 500Ω
18.2kΩ + 1kΩ
9V TO 18V
R1
P1
T
V
(R1 + P1)
V
0.1µF
LOOP
OUT
R
10Ω
OFFSET
4
3
R
250Ω
OFF2
f
L
OUT
5
8
AD654
NB: ATT
NOTE:
C
1.7nF
1.8nF
2.1nF
T
6
1
C
R
T
T
2
1
AND C
A
7
(MIN),
1
T
– SEE TABLE
f
OUT
R
5kΩ
PU
= 0Hz
f
OUT