Transmission gate vs NAND based D flip flop?

[allanvv]

In Baker's book he introduces an edge triggered D flip-flop using transmission gates:

**broken link removed**

However I can't find much information about the advantages and disadvantages of this design compared to the regular NAND implementation. I noticed from simulations that the tgate version worked at higher frequencies and used less power. Does the tgate version have more propagation delay or something? Or maybe I just sized the NAND version wrong (just used the same drive strengths for every gate).

edit: Sorry, should have specified that my question is in the context of designing standard cells

 

[goldsmith]

Hello Dear allanvv
As i understood from your circuit , it is a flip flop that based on nand gates . and it's advantage is , that , the nand gate is popular and base gate , that with that you can make all of the digital systems ( the base gates are : nand nore xnor).
I hope that i understood , your mean correctly.
Best Wishes
Goldsmith

 

[FvM]

The transfer gate design implements a master-slave FF. There are other ways to implement it with bipolar logic that doesn't provide transfer gates, but the MS point is essential for an edge triggered FF.

If I understand right, the below gate construct isn't an edge triggered FF at all, in so far it simply can't be compared with the above one.

 

[allanvv]

I added a clarification that my question is in the context of designing standard cells (ie. transistor level)

Ok, I showed the wrong NAND-based version of a master-slave flip flop. I mean to compare the transmission gate version to the standard version I've seen often in textbooks on digital design (not cell design):

 

[FvM]

I notice, that the circuit shown in post #1 corresponds to the classical 7474, if you omit the asynchronous control signals. In so far it's a good representative, although not exactly functionally equivalent to the TG design. And I was apparently wrong by claiming it's not edge triggered. It actually is, although the structure is less clear than the TG design.

I think, the answer is a pure technology matter. All bipolar FFs are using the gate structure, all CMOS FFs the lower transistor count TG design.