The useful range of a driver is greatly affected by the drive power requirements of the load and the thermal characteristics of the IC package. In order for a power driver to be useful over a particular temperature range, the package must allow for the efficient removal of the heat produced while keeping the junction temperature within rated limits. The UCCx732x family of drivers is available in three different packages to cover a range of application requirements.
The MSOP PowerPAD-8 (DGN) package significantly relieves this concern by offering an effective means of removing the heat from the semiconductor junction. As illustrated in reference , the PowerPAD packages offer a lead-frame die pad that is exposed at the base of the package. This pad is soldered to the copper on the PC board directly underneath the IC package, reducing the θJC down to 4.7°C/W. Data is presented in reference  to show that the power dissipation can be quadrupled in the PowerPAD configuration when compared to the standard packages. The PC board must be designed with thermal lands and thermal vias to complete the heat removal subsystem, as summarized in reference . This design allows a significant improvement in heat sinking over that which is available in the D or P packages, and is shown to more than double the power capability of the D and P packages.
The PowerPAD is not directly connected to any leads of the package. However, the PowerPad is electrically and thermally connected to the substrate which is the ground of the device.