Hi,
We are working on a project to generate quadrature signals from DC to 800MHz for lock-in detection. Therefore, we were thinking about using flip-flops as divide-by-4 dividers to generate the quadrature signals for mixing.
The only flip-flops that we could find that work at such high clock rates are ECL D-flip-flops. Specifically, we bought NB7V52M from OnSemi and SY10EP51 from Microchip to try. We could not get NB7V52M to perform anything meaningful, but we managed to get SY10EP51 to change the output by changing the input on the D port manually on the breadboard.
However, when we connected the invert-Q output to a flip-flop's own D input, the output is stuck in voltage high all the time. To be more specific, the output is logic-high with the clock signal around 50 peak-to-peak mV, which I think is just the clock input coupled onto the output.
Hence, I wonder if it is even possible to use such flip-flops with feedback as frequency dividers or the ECL D-type flip flop require specific configurations to perform as a frequency divider?