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 gate driver device 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 the specified limit. For detailed information regarding the thermal information table, please refer to the Semiconductor and IC Package Thermal Metrics Application Note (SPRA953).

Among the different package options available for the UCC27444-Q1 device, power dissipation capability of the DGN package is of particular mention. The VSSOP-8 (DGN) package offers thermal pad for removing the heat from the semiconductor junction through the bottom of the package. This pad is soldered to the copper on the printed circuit board directly underneath the device package, reducing the thermal resistance to a very low value. This allows a significant improvement in heat-sinking over the D package. The printed circuit board must be designed with thermal lands and thermal vias to complete the heat removal subsystem. Note that the exposed pads in the VSSOP-8 package are not directly connected to any leads of the package, however,PowerPAD is thermally connected to the substrate of the device. TI recommends to externally connect the exposed pads to GND pin of the driver IC in PCB layout.