MIC5264_06 Datasheet, PDF (10/11 Pages) Micrel Semiconductor – 150mA μCap Dual LDO Regulator

Micrel, Inc.
MIC5264 Junction-To-Ambient Thermal Resistance
Package
θ_JA Recommended
Minimum Footprint
θ_JC
2.5mm x 2.5mm
MLF-10
75°C/W
Thermal Resistance
2°C/W
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
63°C/W. The maximum power dissipation must not be
exceeded for proper operation.
For example, when operating the MIC5264PMYML at an
input voltage of 5.0V at 150mA on V_OUT1 and 100mA on
V_OUT2 with a minimum footprint layout, the maximum
ambient operating temperature T_A can be determined as
follows:
MIC5264
0.52W
=
⎜⎜⎝⎛
125°C −
63°C
T_A
⎟⎟⎠⎞
T_A = 92.24°C
Therefore, a 3.0V application at 150mA on Ch1 and 2.8V
at 100mA on Ch2 can accept an ambient operating
temperature of 92°C in a 10-pin 2.5mm x 2.5mm MLF^®
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
May 2006
10
M9999-052406
[phone]