MIC5317 Datasheet, PDF (10/17 Pages) Micrel Semiconductor – High-Performance Single 150mA 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
240°C/W.
The maximum power dissipation must not be exceeded
for proper operation.
For example, when operating the MIC5317-2.8YMT at an
input voltage of 3.6V and 150mA load with a minimum
footprint layout, the maximum ambient operating
temperature T_A can be determined as shown in Equation
4:
0.120W = (125°C – T_A)/(240°C/W)
T_A = 96°C
Eq. 4
Therefore the maximum ambient operating temperature
of 96°C is allowed in a 1mm × 1mm DFN package. 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
MIC5317
August 23, 2013
10
Revision 1.0