I am very new to the audio circuit design, so I apologize in advance if this is a dumb question. I am trying to find an IC which will allow me to take a single I2S signal and a channel enable that allows me to switch between a mono signal (through a class D amp) and a 2ch PCM signal to a toslink connector. I need to do this because one of the time channels in the I2S will be working with phone and the other will be for both of the audio channels. Is there a simple circuit to do this?