I'm trying to understand the SSPND flag of the USB DAC PCM2900. Does the suspend go active when the USB data lines are disconnected... or when the DAC is connected to a USB host, but the host isn't expecting the DAC to do any decoding?
My PCM2900 always has 3.1-3.2V on the SSPND when connected by USB to my PC. Nothing else is connected to SSPND. I was hoping SSPND would go down when there's no decoding going on, because I get a click sound every time I start or stop playing sound. Putting the amplifier IC in suspend, with or without a small time delay, would fix this problem.
http://www.ti.com/lit/ds/symlink/pcm2900c.pdf