Datasheet

20
LT1012A/LT1012
sn1012 1012afbs
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone]
●
FAX: [phone]
●
www.linear.com
LW/TP 1202 1K REV B • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 1991
Kelvin-Sensed Platinum Temperature Sensor Amplifier
U
TYPICAL APPLICATIO
5k*
–15V
20V
2
3
4
–15V
6
7
–
+
LT1012
* = WIRE WOUND RESISTORS
ALL OTHER RESISTORS ARE 1% METAL FILM
TRIM R2 AT 0°C FOR V
0
= 0V
TRIM R3 AT 100°C FOR V
0
= 10V
TRIM R4 AT 50°C FOR V
0
= 5V
IN THE ORDER INDICATED
POSITIVE FEEDBACK (R1) LINEARIZES THE
INHERENT PARABOLIC NONLINEARITY OF
THE PLATINUM SENSOR AND REDUCES
ERRORS FROM 1.2°C TO 0.004°C OVER
THE –50°C TO 150°C RANGE
LT1012A • TA04
R2
100k
10M
10V
REFERENCE
LT1021-10
235k*
392k*
ROSEMOUNT
78S
OR
EQUIVALENT
R
S
5k
R1
182k
R
F
*
654k
6.65M
R3
1k
R4
5k
10k
24.3k
4.75k
200k
619k
100Ω
AT
0°C
V
OUT
= 100mV/°C
–50°C TO 150°C