Pay special attention to the power stage power supply layout.
- Use 4.7 µf for decoupling of VBAT supply.
- Keep the current circulating loops containing the supply decoupling capacitors, the H-bridges in the device and the connections to the speakers as tight as possible to reduce emissions.
- Use ground planes to provide the lowest impedance for power and signal current between the device and the decoupling capacitors. The area directly under the device should be treated as a central ground area for the device, and all device grounds must be connected directly to that area.
- Use a via pattern to connect the area directly under the device to the ground planes in copper layers below the surface. This connection helps to dissipate heat from the device.
- Avoid interrupting the ground plane with circular traces around the device. Interruption disconnects the copper and interrupt flow of heat and current. Radial copper traces are better to use if necessary.