Application information

L6206

22/29

DocID07617 Rev 4

6.3

Thermal management

In most applications the power dissipation in the IC is the main factor that sets the maximum

current that can be delivered by the device in a safe operating condition. Therefore, it has to

be taken into account very carefully. Besides the available space on the PCB, the right

package should be chosen considering the power dissipation. Heatsinking can be achieved

using copper on the PCB with proper area and thickness. Figure 21 and 22 show the

junction to ambient thermal resistance values for the PowerSO36 and SO24 packages.

For instance, using a PowerSO package with a copper slug soldered on a 1.5 mm copper

thickness FR4 board with a 6 cm2 dissipating footprint (copper thickness of 35 µm), the

Rth j-amb is about 35 °C/W. Figure 20 shows mounting methods for this package. Using

a multilayer board with vias to a ground plane, thermal impedance can be reduced down

to 15 °C/W.

Figure 20. Mounting the PowerSO package

Figure 21. PowerSO36 junction ambient thermal resistance versus on-board copper

area

Slug soldered

to PCB with

dissipating area

Slug soldered

to PCB with

dissipating area

plus ground layer

Slug soldered to PCB with

dissipating area plus ground layer

contacted through via holes