Threshold voltage effects and transmission gates

[nikhilgarg.nitk]

1. can anybody tell me about threshold voltage effects?? and how transmission gates eliminates these effects???
2. D-flip flop using transmission gates along with its working??

 

[niladri.s.debnath]

hi nikhil
If u use a ptype or ntype pass transistor only the u will not be able to get a strong logic level at the output, for ntype pass transistor in case u give logic 1 at i/p u will get degraded logic 1 at o/p similarly in ptype pass transistor if u give logic 0 at i/p u will get degraded logic 0 at output the degradation of the i/p will depend on threshold voltage in ntype u wil get Vdd-Vth and in ptype u get Vth at o/p. but when u use transmission gate ptype & ntype are in parallel so the shortcoming of one type is compensated by other type, in this way transmission gate remove these threshold voltage effects.
For the working of D flip flop i will recommend u to read any book on cmos vlsi design there u can find a very good explanation of it . for eg u can go for cmos vlsi design by Neil Weste
I hope u will find this post helpful.

 

[leo_o2]

D-flip flop using transmission gates can work well.
Some tranditional structure is built with transimission gates.