The useful range of a driver is greatly affected by the drive power requirements of the load and the thermal characteristics of the device 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 UCD7K family of drivers is available in PowerPAD™ TSSOP package to cover a range of application requirements. Both have the exposed pads to relieve thermal dissipation from the semiconductor junction.

As illustrated in Reference [2], the PowerPAD™ packages offer a leadframe die pad that is exposed at the base of the package. This pad is soldered to the copper on the PC board (PCB) directly underneath the device package, reducing the Θ_JC down to 4.7°C/W. The PC board must be designed with thermal lands and thermal vias to complete the heat removal subsystem, as summarized in Reference [3].

Note that the PowerPAD™ is not directly connected to any leads of the package. However, it is electrically and thermally connected to the substrate which is the ground of the device.