TMP01FS Analog Devices Inc, TMP01FS Datasheet - Page 13

• Manufacturer Part Number: TMP01FS
• Description: Temperature Sensor IC IC Function:Digital Temperature Sensor
• Manufacturer: Analog Devices Inc

Specifications of TMP01FS

• Package/case: 8-SOIC
• Leaded Process Compatible: No
• Ic Generic Number: 01
• Mounting Type: Surface Mount
• Operating Temp. Max: 125 C
• Operating Temp. Min: -55 C
• Rohs Status: RoHS non-compliant
• Sensing Temperature: -55°C ~ 125°C
• Output Type: Open Collector
• Voltage - Supply: 4.5 V ~ 13.2 V
• Accuracy: ±1°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

BUFFERING THE TEMPERATURE OUTPUT PIN
The VPTAT sensor output is a low impedance dc output voltage
with a 5 mV/K temperature coefficient, that is useful in multiple
measurement and control applications. In many applications,
this voltage needs to be transmitted to a central location for
processing. The buffered VPTAT voltage output is capable of
500 μA drive into 50 pF (maximum).
Consider external amplifiers for interfacing VPTAT to external
circuitry to ensure accuracy, and to minimize loading which
could create dissipation-induced temperature sensing errors.
An excellent general-purpose buffer circuit using the OP177 is
shown in Figure 25. It is capable of driving over 10 mA, and
remains stable under capacitive loads of up to 0.1 μF. Other
interfacing ideas are also provided in this section.
DIFFERENTIAL TRANSMITTER
In noisy industrial environments, it is difficult to send an
accurate analog signal over a significant distance. However,
by sending the signal differentially on a wire pair, these errors
can be significantly reduced. Because the noise is picked up
equally on both wires, a receiver with high common-mode
input rejection can be used to cancel out the noise very effec-
tively at the receiving end. Figure 26 shows two amplifiers used
to send the signal differentially, and an excellent differential
receiver, the AMP03, which features a common-mode rejection
ratio of 95 dB at dc and very low input and drift errors.
R1
R2
R3
1
2
3
4
VREF
GENERATOR
HYSTERESIS
TEMPERATURE
COMPARATOR
SENSOR AND
REFERENCE
VOLTAGE
WINDOW
Figure 26. Send the Signal Differentially for Noise Immunity
TMP01
VPTAT
8
7
6
5
Rev. E | Page 13 of 20
V+
VPTAT
10kΩ
10kΩ
10kΩ
OP297
OP297
1/2
1/2
R1
R2
R3
4 mA TO 20 mA CURRENT LOOP
Another common method of transmitting a signal over long
distances is to use a 4 mA to 20 mA loop, as shown in Figure 27.
An advantage of using a 4 mA to 20 mA loop is that the
accuracy of a current loop is not compromised by voltage drops
across the line. One requirement of 4 mA to 20 mA circuits is
that the remote end must receive all of its power from the loop,
meaning that the circuit must consume less than 4 mA.
Operating from 5 V, the quiescent current of the TMP01 is
500 μA maximum, and the OP90s is 20 μA maximum, totaling
less than 4 mA. Although not shown, the open collector outputs
and temperature setting pins can be connected to do any local
control of switching.
50Ω
50Ω
1
2
3
4
VREF
HYSTERESIS
GENERATOR
Figure 25. Buffer VPTAT to Handle Difficult Loads
TEMPERATURE
COMPARATOR
SENSOR AND
REFERENCE
VOLTAGE
WINDOW
TMP01
VPTAT
V+
V–
AMP03
8
7
6
5
V
OUT
V+
VPTAT
0.1µF
V+
V–
10kΩ
OP177
100Ω
TMP01
V
OUT
C
L