Datasheet

3V
3V
V
REF
3V
V
REF
3V
3V
3V
V
REF
V43
R
2.5k
SET1
W
A
+
I
REF1
+
-
+
U3
OPA333
R
2.5k
SET2
W
A
+
I
REF2
R
2k
1
W
R
100
ZERO
W
RWb
3W
RWc
4W
RWd
3W
RWa
3W
+
-
+
U2
OPA333
C
470nF
7
OUTF
GNDF
OUTS
GNDS
In
EN
U1REF3212
+
-
+
OPA3331OPA333
V
+
VRTD
VT25
VT+
VT-
Mon+ Mon-
RTD+
RTD-
EMU21RTD3
R
100k
GAIN
W
V
DIFF
T3BF256A
T1BF256A
UseBF861A
UseBF861A
G
S
RTDResistance
(Volts=Ohms)
Temp( C)
(Volts= C)
°
°
Pt100RTD
PGA112
MSP430
V
REF+
+
RG
V+
V-
Ref
_
2
1
8
3
6
7
5
4 U1 INA333
3V
RG
Out
INA333
www.ti.com ..................................................................................................................................................... SBOS445B – JULY 2008 – REVISED OCTOBER 2008
RWa, RWb, RWc, and RWd simulate wire resistance. These resistors are included to show the four-wire sense technique immunity to line
mismatches. This method assumes the use of a four-wire RTD.
Figure 39. Four-Wire, 3V Conditioner for a PT100 RTD With Programmable Gain Acquisition System
To download a compressed file that contains the TINA-TI simulation file for this circuit, click the following link:
PT100 RTD .
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Product Folder Link(s): INA333