Datasheet

0
0.4
0.6
0.8
1.0
1.8
0.2
0 20 40 60 14080 100 120
T
A
- Ambient Temperature - °C
P
D
- Power Dissipation - W
0
150
250
500
LFM
1.2
1.6
1.4
LFM = 0
LFM = 150
LFM = 250
LFM = 500
PowerPAD Package
TPS55383 , , TPS55386
SLUS818 – SEPTEMBER 2008 ......................................................................................................................................................................................... www.ti.com
POWER DISSIPATION
vs
AMBIENT TEMPERATURE
Figure 30. Power Derating Curves
The PowerPAD package provides low thermal impedance for heat removal from the device. The PowerPAD
derives its name and low thermal impedance from the large bonding pad on the bottom of the device. The circuit
board must have an area of solder-tinned-copper underneath the package. The dimensions of this area depend
on the size of the PowerPAD package. Thermal vias connect this area to internal or external copper planes and
should have a drill diameter sufficiently small so that the via hole is effectively plugged when the barrel of the via
is plated with copper. This plug is needed to prevent wicking the solder away from the interface between the
package body and the solder-tinned area under the device during solder reflow. Drill diameters of 0.33 mm (13
mils) work well when 1-oz. copper is plated at the surface of the board while simultaneously plating the barrel of
the via. If the thermal vias are not plugged when the copper plating is performed, then a solder mask material
should be used to cap the vias with a diameter equal to the via diameter of 0.1 mm minimum. This capping
prevents the solder from being wicked through the thermal vias and potentially creating a solder void under the
package. (See the Additional References section.)
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Product Folder Link(s): TPS55383 TPS55386