Use an unbroken ground plane to have good low impedance and inductance return path to the power supply for power and audio signals.
Maintain a contiguous ground plane from the ground pins to the PCB area surrounding the device for as many of the ground pins as possible, since the ground pins are the best conductors of heat in the package.
PCB layout, audio performance and EMI are linked closely together.
Routing the audio input is kept short and
together with the accompanied audio source ground.
The small bypass capacitors on the PVDD lines is
placed as close the PVDD pins as possible.
A local ground area underneath the device is important to keep solid to minimize ground bounce.
Orient the passive component so that the narrow end of the passive component is facing the TPA3221 device, unless the area between two pads of a passive component is large enough to allow copper to flow in between the two pads.
Avoid placing other heat producing components or structures near the TPA3221 device.
Avoid cutting off the flow of heat from the TPA3221 device to the surrounding ground areas with traces or via strings, especially on output side of device.