Micrel, Inc.

MIC5528

operating temperature will give the maximum operating

conditions for the regulator circuit. The junction-to-

ambient thermal resistance for the minimum footprint is

173°C/W.

The maximum power dissipation must not be exceeded

for proper operation.

For example, when operating the MIC5528-3.3YMX at an

input voltage of 3.6V and a 500mA load with a minimum

footprint

layout,

the

maximum

ambient

operating

(

) (

)

C

99

T

W

/

C

173

/

T

C

125

W

15

.

0

A

A

°

=

°

−

°

=

Eq. 4

Therefore, the maximum ambient operating temperature

allowed in a thermally enhanced 1.2mm × 1.2mm XTDFN

package is 99°C. 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

May 5, 2014

9

Revision 1.1