Electrical – USB 2.0 full speed audio class max sampling frequency

adcaudiousb device

what is the maximum achivable sampling frequency when using USB 2.0 full speed isochronous audio transfer and stereo 24bit format (recording only) ?

when no compression is used !

Best Answer

USB2.0 full speed is the same as USB1.1 full speed.

USB1.1 frames have a length of 1ms, and isochronous transfers may put up to 1023 bytes into a frame. This gives you roughly 170 stereo 24bit samples per frame – a 170ksample/s rate.

Even the simplest compression techniques as transferring the difference to the previous value instead of the actual value or joint-stereo, followed by special encoding for small difference values may nearly double that rate.