AMS385-1.2 ADMOS [Advanced Monolithic Systems], AMS385-1.2 Datasheet - Page 5

• Manufacturer Part Number: AMS385-1.2
• Description: MICROPOWER VOLTAGE REFERENCE DIODE
• Manufacturer: ADMOS [Advanced Monolithic Systems]

TYPICAL APPLICATIONS
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone [phone] Fax [phone]
MERCURY
THERMOCOUPLE
1.345V
CELL
Micropower Thermocouple Cold Junction Compensator
+
-1.5V TO -27V
5.1k
+
-
AMS385-1.2
COLD JUNCTION
ISO THERMAL
WITH LM334
1M
1%
I
OUT
*
ZERO ADJ
100k
R2
R1
100k
V
+
(Continued)
2
3
LM334
-
+
+
-
LM312
METER
V
R1
AMS385-1.2
-
-30V
150pF
C1
7
4
R
6
R2
Precision 1 A to 1mA Current Sources
2k
1%
*I
OUT
TC ADJ
500
=1.23V/R2
Adjustment Procedure
1. Adjust TC ADJ pot until voltage across R1 equals Kelvin temperature
multiplied by the thermocouple Seebeck coefficient.
2. Adjust ZERO ADJ pot until voltage across R2 equals the thermocouple
Seebeck coefficient multiplied by 273.2.
Thermocouple
Typical supply current 50 A
Type
1.5V TO 27V
J
T
K
S
AMS285-1.2/AMS385-1.2
Coefficient
I
Seebeck
OUT
(mV/ C)
52.3
42.8
40.8
R1
100k
*
6.4
2
3
-
+
63.4
( )
523
432
408
LM312
R1
30V
7
4
1.24k
( ) Across R1
953
150
R2
AMS385-1.2
1k
150pF
6
C1
R2
@ 25 C (mV)
Voltage
12.17
12.77
1.908
15.60
Across R2
Voltage
11.17
11.78
1.766
14.32
(mV)