The BTL Class-D power amplifier uses the TDA8920 Chip Amp, more precisely the TDA8920CTH for the SMD version, and on the following occasion, I will share the schema in PDF file format along with the PCB Layout for the SMD component version, which you can download at the end of the post.
This Class-D Power Amplifier has a pretty good power efficiency and is anticipated to be of very little power. Besides this TDA8920 amplifier is also wide for the supply voltage, it can be supplied from 12.5VDC to 30VDC symmetrically. This amplifier also has quite complete features that are already "built-in" inside the chip itself. These features include Over Current Protection, Current Limiter, Under Voltage Protection, Over Voltage Protection. The power that can be generated by this amplifier 100W RMS per channel in BTL 200W RMS, it can be seen in the datasheet.
The following is the BTL TDA8920 amplifier circuit scheme that I schemed at EasyEDA:
From the schematic above, I add Oscillator power amplifier using LTC6905CS5-80, if you are having trouble finding LTC6905CS5-80, the BTL TDA8920 amplifier circuit can also be made in self-oscillation mode by adding a 22K Ohm resistor 7 pined to VSSA voltage (V-)
Following is the scheme for self oscilation mode.
And to facilitate assembly, I have also made a double layer version of the PCB layout which you can download at the link below, this PCB layout version is the oscillator mode so to use the self OSC mode, the oscillator section does not need to be filled directly with jumpers as in the Self OSC scheme above.
Below the video assembly and test: