how to improve the speed of demultiplexer? tks

[ring119]

Hi, everyone, i'm designing a 1:8 demultiplexer using CMOS 65nm technology. It works properly @ 2.5GHz, but fails @ 5GHz or even higher frequency. Can anyone tell me how to improve the speed of demultiplexer? Thanks in advance.

The schematic is used as attached. The transistor width i used is small, around 2-3um.

 

[AdvaRes]

Hi,

Your problem comes from the fact that the AND4 introduce a big delay. In order to reduce it try to use many AND2 gates instead of only one AND4.

Another solution: You can use 1:2 demux to built your 1:8 Demux.