MIC5524 Datasheet, PDF (9/13 Pages) Micrel Semiconductor – High-Performance 500mA LDO

Micrel, Inc.
Substituting P_D for P_D(MAX) and solving for the ambient
operating temperature will give the maximum operating
conditions for the regulator circuit. The junction-to-
ambient thermal resistance for the minimum footprint is
250°C/W.
The maximum power dissipation must not be exceeded
for proper operation.
For example, when operating the MIC5524-3.3YMT at an
input voltage of 3.6V and a 500mA load with a minimum
footprint layout, the maximum ambient operating
temperature T_A can be determined as in Equation 4:
0.15W = (125°C − T_A )/(250°C / W )
T_A = 87.5°C
Eq. 4
Therefore, the maximum ambient operating temperature
allowed in a 1mm × 1mm TDFN 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
MIC5524
May 15, 2013
9
Revision 1.0