problem with high voltage generator for bootstrap switch

[nus_lin]

dear guys, i assume that the high voltage generator for bootstrap switch in a S/H circuit is quite familiar to most of you.

i am designing one using 65nm tech. but i could not find the breakdown voltage for the source/drain junction, and i am not sure how high it can experience without breakdown. with a 1.2V supply, one of the transistors in the charge-pump part experiences a 2.3-1.2v swing, is it safe?

 

[erikl]

You should find the max. permitted voltage in your PDK doc. Usually max. Vds may be a bit larger than max. Vgs.