The 176-pin PGF/PTP low-profile quad flatpack (LQFP) pin assignments are shown in Figure 4-1. The 179-ball ZHH ball grid array (BGA) terminal assignments are shown in Figure 4-2 through Figure 4-5. The 176-ball ZJZ plastic BGA terminal assignments are shown in Figure 4-6 through Figure 4-9. Table 4-1 describes the function(s) of each pin.
The thermal pad should be soldered to the ground (GND) plane of the PCB because this will provide the best thermal conduction path. For this device, the thermal pad is not electrically shorted to the internal die VSS; therefore, the thermal pad does not provide an electrical connection to the PCB ground. To make optimum use of the thermal efficiencies designed into the PowerPAD™ package, the PCB must be designed with this technology in mind. A thermal land is required on the surface of the PCB directly underneath the thermal pad. The thermal land should be soldered to the thermal pad; the thermal land should be as large as needed to dissipate the required heat. An array of thermal vias should be used to connect the thermal pad to the internal GND plane of the board. See PowerPAD™ thermally enhanced package for more details on using the PowerPAD package.