LM285BYZ-2.5 National Semiconductor, LM285BYZ-2.5 Datasheet - Page 8

• Manufacturer Part Number: LM285BYZ-2.5
• Description: Voltage Reference
• Manufacturer: National Semiconductor

Specifications of LM285BYZ-2.5

• Peak Reflow Compatible (260 C): No
• Leaded Process Compatible: No
• Reference Volt Tolerance ±%: 0.8%
• Mounting Type: Through Hole
• Supply Current: 10mA
• Package / Case: 3-TO-92
• Voltage Reference Type: Shunt
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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LM385-2.5 Applications
METER THERMOMETERS
Calibration
1. Short LM385-2.5, adjust R3 for I
2. Remove short, adjust R2 for correct reading in
Calibration
1. Short LM385-2.5, adjust R3 for I
2. Remove short, adjust R2 for correct reading in ˚F
centigrade
0˚C–100˚C Thermomemter
0˚F–50˚F Thermomemter
Typical supply current 50 µA
Thermocouple
Type
T
K
S
OUT
OUT
J
=temp at 1µA/˚K
=temp at 1.8 µA/˚K
00551927
00551926
(Continued)
Seebeck
efficient
(
µ
52.3
42.8
40.8
Co-
V/˚C)
6.4
63.4 150Ω
523 1.24k
432
412 953Ω
(Ω)
R1
8
(Ω)
R2
1k
Adjustment Procedure
1. Adjust TC ADJ pot until voltage across R1 equals Kelvin
2. Adjust zero ADJ pot until voltage across R2 equals the
temperature multiplied by the thermocouple Seebeck
coefficient.
thermocouple Seebeck coefficient multiplied by 273.2.
Across R1
Voltage
@
Micropower Thermocouple Cold Junction
15.60
12.77
12.17
1.908
(mV)
25˚C
Across R2
Voltage
14.32
11.78
11.17
1.766
(mV)
Compensator
00551906