LM70CIMMX-5/HALF National Semiconductor, LM70CIMMX-5/HALF Datasheet - Page 11

• Manufacturer Part Number: LM70CIMMX-5/HALF
• Manufacturer: National Semiconductor

Specifications of LM70CIMMX-5/HALF

• Lead Free Status / Rohs Status: Supplier Unconfirmed

2.0 Serial Bus Timing Diagrams
3.0 Application Hints
To get the expected results when measuring temperature
with an integrated circuit temperature sensor like the LM70,
it is important to understand that the sensor measures its
own die temperature. For the LM70, the best thermal path
between the die and the outside world is through the LM70’s
pins. In the MSOP-8 package the ground pin is connected to
the back side of the LM70 die and thus has the most effect
on the die temperature. Although the other pins will also
have some effect on the LM70die temperature and therefore
should not be discounted. The LM70 will provide an accurate
measurement of the temperature of the printed circuit board
on which it is mounted, because the pins represent a good
thermal path to the die. A less efficient thermal path exists
a) Reading Continuous Conversion - Single Eight-Bit Frame
b) Reading Continuous Conversion - Two Eight-Bit Frames
c) Writing Shutdown Control
FIGURE 7. Timing Diagrams
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between the plastic package and the LM70 die. If the ambi-
ent air temperature is significantly different from the printed
circuit board temperature, it will have a small effect on the
measured temperature.
In probe-type applications, the LM70 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
LM70 and accompanying wiring and circuits must be kept
insulated and dry, to avoid leakage 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 paints or dips are
often used to insure that moisture cannot corrode the LM70
or its connections.
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