No it is not common at all. Driving a signal into a device that is not powered is hardly ever encountered.
A DVD player with digital output plugged into an amplifier
And no doubt consumer electronics is designed to be idiot proof.
If the two sub systems can be independently powered then a seriese resistor and catching diodes to each rail are a must.
How can a USB device be plugged in and not powered?
Is that considered ESD protection
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16