Digital PDM-input mono 3.4 W Class-D audio amplifier TFA9881 stereo evaluation board

The demo board is designed to operate the TFA9881 device easily. The demo board can be used in two different configurations. A first configuration is a stand-alone configuration with the main demo board only, and a second Cyclone configuration comprises the main demo board plus a Cyclone III FPGA-board. In the stand alone configuration the audio input needs to be a PDM audio signal which goes directly to the amplifier input. In the Cyclone configuration the input can be either an I²S or analog audio signal. This will be converted to a PDM-audio stream by the FPGA which then goes into the amplifier. The FPGA is also used to embed TFA9881 specific control tokens into the PDM audio stream. The included software can be used to control the demo board from a PC environment.