ya, for IC's i can see the datasheets. But I wanted to design a TDC of my own, say a simple vernier delay line TDC. Based on what should I fix the limit of my input rise timeHi,
I don't understand your question .... because we don't know which IC you use nor do we know your application requirements.
If I wanted to know this, I'd read it's datasheet.
yes, how much should it be fast, timing uncertainity i get it.At least fast enough to allow clear edge detection, preferably fast enough not to introduce additional timing uncertainty.