Custom digital design

[hoo]

In custom digital design , how can I determine the values of(width,length) of transistor , for example for comparator or flip-flop?

 

[legendkiller]

Width and length are dependent on the process you are using. for a 45nm technology, the minimum length you can have is 45nm. You can also customize the width and length for tuning the digital circuit. for example, if you want equal rise,fall times, you size the nmos and pmos in the ratio of 1:3.