4.0

MOUNTING CONSIDERATIONS

The majority of the temperature that the LM56 is measuring

is the temperature of its leads. Therefore, when the LM56 is

placed on a printed circuit board, it is not sensing the tem-

perature of the ambient air. It is actually sensing the tem-

perature difference of the air and the lands and printed circuit

board that the leads are attached to. The most accurate tem-

perature sensing is obtained when the ambient temperature

is equivalent to the LM56’s lead temperature.

As with any IC, the LM56 and accompanying wiring and cir-

cuits must be kept insulated and dry, to avoid leakage and

corrosion. This is especially true if the cirucit 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 ensure that moisture

cannot corrode the LM56 or its connections.

DS012893-18

FIGURE 3. Simplified Schematic

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