What is pcm2902?

Hearts of the circuit is PCM2902 which is complete USB audio codec. Maximum sample frequency is 48kHz. Integrated circuit includes USB controller for ADC and DAC, HID part for three buttons, output volume control and S/PDIF encoder and decoder. Circuit is based on recommended circuit from datasheet.

What is the difference between analog and digital output of pcm2902?

PCM2902 automatically switch from analog input signal to digital, when it detects presence of S/PDIF signal. Analog output doesn’t have additional amplifier, that we can’t connect them directly to low impedance headphones.

How to connect pcm2902 S/PDIF to low impedance headphones?

PCM2902 automatically switch from analog input signal to digital, when it detects presence of S/PDIF signal. Analog output doesn’t have additional amplifier, that we can’t connect them directly to low impedance headphones. It should be connected to external amplifier.