FM51 Fairchild Semiconductor, FM51 Datasheet - Page 4

• Manufacturer Part Number: FM51
• Description: Low Voltage High Drive Temperature Sensor
• Manufacturer: Fairchild Semiconductor

FM51 Rev. C
The FM51 can be easily mounted by gluing or cementing it to a
surface. In this case, its temperature will be within about 0.2°C of
the temperature of the surface it is attached to if the ambient air
temperature is almost the same as the surface temperature. If the
air temperature is much higher or lower than the surface tempera-
ture, the actual temperature of the FM51 die will be at an
intermediate temperature between the surface temperature and
the air temperature.
To ensure good thermal conductivity, the backside of the FM51 die
is directly attached to the GND pin. The lands and traces to the
FM51 will, of course, be part of the printed circuit board, which is
the object whose temperature is being measured. These printed
-50 -40
Temperature ( C) =
-25
1750
100
750
500
V
OUT
Temperature ( C)
0
(mV)
25
circuit board lands and traces will not cause the FM51’s tempera-
ture to deviate from the desired temperature.
Alternatively, the FM51 can be mounted inside a sealed-end metal
tube, and can then be dipped into a bath or screwed into a
threaded hole in a tank. As with any IC, the FM51 and accompa-
nying wiring and circuits must be kept insulated and dry to avoid
leak1ge and corrosion. This is especially true if the circuit may
operate at cold temperatures where condensation can occur.
Printed-circuit coatings and varnishes such as Humiseal and
epoxy paint or dips can be used to ensure that moisture cannot
corrode the FM51 or its connections.
V
10 mV/ C
OUT
- 500 mV
50
75
100
125
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