300mA CMOS L.D.O. Regulator

LM1108

HTC

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EQUATION 2-2:

Table 2-1 shows various values of θJA for the LM1108 versus board copper area.

TABLE 2-1 : THERMAL RESISTANCE GUIDELINES FOR LM1108

Equation 2-1can be used in conjunction with Equation 2-2 to ensure regulator thermal operation is within limits.

For example:

In this example, the LM1108 dissipates a maximum of 260mW; below the allow able limit of 508 mW. In a

similar manner, Equation 2-1 and Equation 2-2 can be used to calculate maximum current and/or input voltage