Micrel, Inc.

MIC5313

July 2008

9

M9999-070208-A

To

determine

the

maximum

ambient

operating

temperature of the package, use the junction-to-ambient

thermal resistance of the device and the following basic

equation:

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

−

=

JA

A

J(MAX)

D(MAX)

θ

T

T

P

the die. The junction-to-ambient thermal resistance for

operating temperature will give the maximum operating

conditions for the regulator circuit.

The maximum power dissipation must not be exceeded

for proper operation.

For example, when operating the MIC5313-FCYMT at

an input voltage of 1.8V and 300mA, loads at each

output with a minimum footprint layout, the maximum

follows:

For a full discussion of heat sinking and thermal effects

on voltage regulators, refer to the “Regulator Thermals”

section of Micrel’s Designing with Low-Dropout Voltage

Regulators

handbook. This information can be found on

Micrel's website at:

http://www.micrel.com/_PDF/other/LDOBk_ds.pdf