your last option is exactly what I did recently.
I get clean square waves with minimum under/overshoot and short risetimes.
I measured both rise and decay time to be of 750 ps but this is probably limited by my scope bandwidth.
I get a 1.3 volt signal (terminated) out of my 3V battery
The output impedance of 74lvc1g* devices is ~7ohms, so with a series 143ohm resistor the output impedance is ~150ohms. Hence one easy technique is to have three parallel sections of (74lvc1g14 plus a series 143ohm resistor). That gives rise times <1ns.
The output impedance of 74lvc1g* devices is ~7ohms, so with a series 143ohm resistor the output impedance is ~150ohms. Hence one easy technique is to have three parallel sections of (74lvc1g14 plus a series 143ohm resistor). That gives rise times <1ns.Given the rise/fall times we're talking about here, I'd worry about differential propagation delay through the paralleled sections. Even if they're in the same physical package (minimizing die-to-die process differences), even the die paths and bonding wire lengths could have a measurable effect.
I expect the rise/decay time to come from the bandwidth/slew rate of the chips.