LM185BYH-1.2-SMD National Semiconductor Corporation, LM185BYH-1.2-SMD Datasheet - Page 8

• Manufacturer Part Number: LM185BYH-1.2-SMD
• Description: V-ref Precision 1.235v 20ma 2-pin To-46 Tray
• Manufacturer: National Semiconductor Corporation

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Typical Applications
METER THERMOMETERS
Calibration
1. Short LM385-1.2, adjust R3 for I
2. Remove short, adjust R2 for correct reading in centigrade
I
*2N3638 or 2N2907 select for inverse H
Calibration
1. Short LM385-1.2, adjust R3 for I
2. Remove short, adjust R2 for correct reading in ˚F
Typical supply current 50µA
†
†
‡
Q
I
Select for operation at 1.3V
I
Q
Q
at 1.6V.2.4mA
at 1.3V.500µA
. 600µA to 900µA
Lower Power Thermometer
0˚C−100˚C Thermometer
0˚F−50˚F Thermometer
OUT
OUT
= temp at 1µA/˚K
= temp at 1.8µA/˚K
FE
. 5
(Continued)
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20156129
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8
Thermocouple
Calibration
1. Adjust R1 so that V1 = temp at 1mV/˚K
2. Adjust V2 to 273.2mV
†
age = 50µA to 150µA
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.
I
Q
for 1.3V to 1.6V battery volt-
Type
K
S
J
T
Micropower Thermocouple Cold Junction
Coefficient (Ω) (Ω)
Centigrade Thermometer
Seebeck
(µV/˚C)
52.3
42.8
40.8
6.4
Compensator
63.4 150Ω
523 1.24k
432 1k
412 953Ω
R1 R2
Voltage
Across
@
15.60
12.77
12.17
1.908
(mV)
R1
25˚C
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20156131
Voltage
Across
14.32
11.78
11.17
1.766
(mV)
R2