I wonder, how can I make edge detecting circuit without using any logic IC's, using only transistors & passive components?
I have digital signal with ~15ns fronts on my digital input (5v TTL), and I want to get 20-50ns long pulses(with ~10-20ns transitions) on the front edge of the input pulse.
What I tried to do is capacitor + resistor and then push-pull BJT cascade - I am getting nice front(~15ns), but trialling edge is just terrible (200ns) - capacitor slooooowly discharges...
Probably push-pull cascase I am using (see first answer Prevent high-side BJT saturation) is not very 'digital' - i.e. it's too linear... If there is a way to make more Schmitt-like , probably that would solve this capacitor discharge problem...
Any ideas?