Hi All,

Is there any particular reason why most of the USB IO Transceivers,prefer Pull-up circuit at the output?

Thanks

Most of the time, USB will be in idle mode, then the driver can be in tristate mode (not consuming power) and let the weak pull up resistor pull the signal to a known voltage instead of tristate/floating. Beside this, receiver also need to sense the speed mode based on the pull-up resistor setting.