10.3.2 Heatsinking

The PowerPAD™ package uses an exposed pad to remove heat from the device. For proper operation, this pad must be thermally connected to copper on the PCB to dissipate heat. On a multi-layer PCB with a ground plane, this can be accomplished by adding a number of vias to connect the thermal pad to the ground plane. On PCBs without internal planes, copper area can be added on either side of the PCB to dissipate heat. If the copper area is on the opposite side of the PCB from the device, thermal vias are used to transfer the heat between top and bottom layers.

For details about how to design the PCB, see TI application report, PowerPAD™ Thermally Enhanced Package (SLMA002), and TI application brief, PowerPAD™ Made Easy (SLMA004), available at www.ti.com.

In general, the more copper area that can be provided, the more power can be dissipated.