PCB Design
The chip is mounted on a PCB inside of a socket. The PCB was designed in KiCAD. The main parts of PCB are marked on the diagram.
PCB Schematic
The various parts of the schematic are shown below.
These are device connections. All output pins are shorted together. So are Vdd and Vss.
Supply decoupling capacitors bank to reduce switching noise.
Two different LDOs were used to provide Vdd_analog and Vdd_switching. Switching LDO should have high output current. (3Amp)
Different reference voltages are generated using resistor dividers and potentiometers for extra tunability.
Audio Jack for input interface. High pass filter to remove DC of input and set to Vdd/2.
Output PWM are filtered using LC filter of cutoff ~25KHz.
Current references are created using potentiometers for additional tunability.
Potentiometers to control gain of Class - D amplifier.
Tone control filter circuitry. Options to bypass tone control circuitry.