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FEATURES
G
CALIBRATION CAPABILITY
G
INTEGRAL SENSOR EXCITATION
G
OPEN CIRCUIT SENSOR DETECTION
G
LOW POWER: 80mW
G
INSTRUMENT AMPLIFIER INPUT
G
PROGRAMMABLE GAIN
G
12-BIT LINEARITY
G
TWO ISOLATED POWER SUPPLIES:
±
13V at 5mA
G
LOW DRIFT 10V REFERENCE
APPLICATIONS
G
UNIVERSAL INPUT CHANNEL FOR
PROCESS CONTROL SYSTEMS
G
ISOLATED MEASUREMENT CHANNEL
FOR THERMOCOUPLE, RTD AND
VOLTAGE TRANSDUCERS
G
CHANNEL TO CHANNEL ISOLATED
MULTIPLEXED SYSTEMS
G
ISOLATED 4 TO 20mA RECEIVER
DESCRIPTION
The ISC300 is an isolated measurement channel with
open circuit sensor detection for use with RTD and
thermocouple temperature sensors. In addition to tem-
perature measurement, the ISC300 can accept full
scale input voltages of
±
100mV and
±
10V which
allows use with other sensors such as pressure, humid-
ity and flow sensors. The low level resistance mea-
surement capability also allows stimulus and measure-
ment of strain gauges. The measurement channel has
a highly stable internal reference which can be se-
lected from the output side. This allows the user to
calibrate each channel at the factory, record the cali-
bration data and periodically recalibrate the system
while in use over time and ambient temperature
changes.
SELECT
and GAIN
RST
CLK
No Change
No Change
Latch
RESET
1
1
1
0
0
1
^
X
INPUT
SELECT
A
1
A
0
Com
1
+0.1V
+10V
Signal
0
0
1
1
0
1
0
1
GAIN
SELECT
G
0.5
50
0
1
Channel 1 Out
MUX
PGA
Channel 4
A
1
A
0
Channel 3
Channel 2
Ref
0.100V
Com 1
10.0V
99R
R
Current
Reference
20M
Filter
Modulate
Demod
Power
Rectify
Com 1
Com 2
O
P
T
O
C
O
U
P
L
E
L
A
T
C
H
Out
V
CC
(+15)
CKI
Com 2
V
DD
(+5)
CLK
G
A
0
A
1
RST
DCom 2
28
25
26
27
18
22
19
20
21
23
24
20M
+V
ISO
–V
ISO
+V
ISO
–V
ISO
Sense 2
+I
P
–I
P
Sense 1
V
REF
I
REF1
I
REF2
Com 1
–V
ISO
2
8
5
6
3
1
4
7
10
9
Barrier
Output Side
Input Side
ISC300
International Airport Industrial Park Mailing Address: PO Box 11400 Tucson, AZ 85734 Street Address: 6730 S. Tucson Blvd. Tucson, AZ 85706
Tel: (520) 746-1111 Twx: 910-952-1111 Cable: BBRCORP Telex: 066-6491 FAX: (520) 889-1510 Immediate Product Info: (800) 548-6132
Universal Precision Isolated
MEASUREMENT CHANNEL
1991 Burr-Brown Corporation
PDS-1135A
Printed in U.S.A. October, 1993