It’s difficult because a rise time of zero is physically impossible. You can’t instantaneously jump from one voltage to another in real life; There’s always a transient response. Circuits are made of physical components and electrons are moving objects.
lol 0.02 microseconds is 0.00000002 seconds. Don’t know electronics tho. No idea what exactly makes it difficult.
It’s difficult because a rise time of zero is physically impossible. You can’t instantaneously jump from one voltage to another in real life; There’s always a transient response. Circuits are made of physical components and electrons are moving objects.