This is a d/a converter module using TI’s PCM5102A.
The chip can accept 16-, 24-, and 32-bit data, and should perform much better than my homebrew 4-bit dac.
The interface is I2S, and should easily implemented in a FPGA.
The waveforms show LRCK and DATA. A fixed 32-bit pattern of 32’b1111_0000_1100_1010_0000_1100_1100_0000 is continually sent for both L and R channels.