OP496_15 Datasheet, PDF (15/19 Pages) Analog Devices – Micropower RRIO Operational Amplifiers

200⍀
10-TURNS
26.7k⍀
26.7k⍀
100⍀
RTD
2.55M⍀
6.17k⍀
100⍀
1/4
OP496
A1
GAIN = 259
1/4
OP496
A2
5V
1/4
OP496
A3
V_OUT
392⍀ 392⍀
100k⍀
100k⍀
20k⍀
0.1␮F
AD589
37.4k⍀
NOTE:
ALL RESISTORS 1% OR BETTER
5V
Figure 12. A Single-Supply RTD Amplifier
OP196/OP296/OP496
Amplifiers A2 and A3 are configured in a two op amp instru-
mentation amplifier configuration. For ease of measurement,
the IA resistors are chosen to produce a gain of 259, so that
each 1°C increase in temperature results in a 10 mV increase in
the output voltage. To reduce measurement noise, the band-
width of the amplifier is limited. A 0.1 µF capacitor, connected
in parallel with the 100 kΩ resistor on amplifier A3, creates a
pole at 16 Hz.
* OP496 SPICE Macro-model
REV. C, 5/95
*
ARG / ADSC
*
* Copyright 1995 by Analog Devices, Inc.
*
* Refer to “README.DOC” file for License Statement.
* Use of this model indicates your acceptance of the
* terms and provisions in the License Statement.
*
* Node assignments
*
Noninverting input
*
Inverting input
*
Positive supply
*
Negative supply
*
Output
*
*
.SUBCKT OP496 1
2
99 50 49
*
* INPUT STAGE
*
IREF 21 50 1U
QB1 21 21 99 99 QP 1
QB2 22 21 99 99 QP 1
QB3 4 21 99 99 QP 1.5
QB4 22 22 50 50 QN 2
QB5 11 22 50 50 QN 3
Q1 5
4
7
50 QN 2
Q2 6
4
8
50 QN 2
Q3 4
4
7
50 QN 1
Q4 4
4
8
50 QN 1
Q5 50 1
7
99 QP 2
Q6 50 3
8
99 QP 2
EOS 3
2
POLY(1) (17,98) 35U 1
Q7 99 1
9
50 QN 2
Q8 99 3
10 50 QN 2
Q9 12 11 9
99 QP 2
Q10 13 11 10 99 QP 2
Q11 11 11 9
99 QP 1
Q12 11 11 10 99 QP 1
R1 99 5
50K
R2 99 6
50K
R3 12 50 50K
R4 13 50 50K
IOS 1
2
0.75N
C10 5
6
3.183P
C11 12 13 3.183P
CIN 1
2
1P
*
* GAIN STAGE
*
EREF 98 0 POLY(2) (99,0) (50,0) 0 0.5 0.5
G1 98 15 POLY(2) (6,5) (13,12) 0 10U 10U
R10 15 98 251.641MEG
CC 15 49 8P
D1 15 99 DX
D2 50 15 DX
*
* COMMON-MODE STAGE
*
ECM 16 98 POLY(2) (1,98) (2,98) 0 0.5 0.5
R11 16 17 1MEG
R12 17 98 10
*
* OUTPUT STAGE
*
ISY 99 50 20U
EIN 35 50 POLY(1) (15,98) 1.42735 1
Q24 37 35 36 50 QN 1
QD4 37 37 38 99 QP 1
Q27 40 37 38 99 QP 1
R5 36 39 150K
R6 99 38 45K
Q26 39 42 50 50 QN 3
QD5 40 40 39 50 QN 1
Q28 41 40 44 50 QN 1
QL1 37 41 99 99 QP 1
R7 99 41 10.7K
I4 99 43 2U
QD7 42 42 50 50 QN 2
QD6 43 43 42 50 QN 2
Q29 47 43 44 50 QN 1
Q30 44 45 50 50 QN 1.5
QD10 45 46 50 50 QN 1
R9 45 46 175
Q31 46 47 48 99 QP 1
QD8 47 47 48 99 QP 1
QD9 48 48 51 99 QP 5
R8 99 51 2.9K
I5 99 46 1U
Q32 49 48 99 99 QP 10
Q33 49 44 50 50 QN 4
.MODEL DX D()
.MODEL QN NPN(BF=120VAF=100)
.MODEL QP PNP(BF=80 VAF=60)
.ENDS
REV. E
–15–