Re: Fw: Re: Fw: Re: Fw: Re: Fw: Re: [softrock40] FST switches
Tony has certainly initiated a lot of thinking with his SR series.
Let's not blame him entirely::>
I believe "ACT" logic will go 160Mhz so, no problem.
Right you are!!! Good call! 74ACT74 by Fairchild Semi operates at (typical) 160 MHz, draws 20 ua.
I need more test fixturing capability here to try variations, but at these frequencies, wiring and layout has enough of an effect to where an imbedded board is needed when you want to try another switching scheme. Maybe someone else has ideas ?
As you push towards the higher frequencies, you need multilayer board, careful layout and short traces. It gets expensive because bread-boarding is not practical for operating at the higher frequencies. Typically, you do prototyping at 1/4 or 1/3 of the max frequency. After it works at lower frequencies, then you design a board for the full boogie attempt.
I was just looking at ECL logic when your message to the list came in Kees. ECL is a disaster, although the basic D type flip flop can be clocked at 1100 MHz (minimum). But, the single flip flop takes 70 ma supply current (ouch). A basic divide by 2 gate takes 30 ma! I didn't even look at the price::>
I wonder if anyone has considered rolling their own PIN diode switches????
GL to all.