Robert,
Bob Camp mention Collins low jitter hard limiters but I suspect that's much more of an issue on the very shallow slopes you see on 5 or 10 Hz mixer outputs. The LTC6957 is probably overkill on 10 MHz inputs but I believe they're a tad better than a 74AC gate, but then again maybe not all that much better. Lot more expensive. Bob C discussed sine to square conversion in a recent post (IIRC) perhaps in connection with 5V to 3.3V conversion, and for a low cost solution the 74AC gate looks pretty good and they're easy to dead bug.
Sine-to-square conversion and Collins low jitter hard limiters is related to slew-rate limited resolution.
If you have 1E-12 resolution, and see about 20 steps, then over a period of 20 ps the sampler is unable to make a stable sampling. For a 74AC that is not very surprising. You might benefit from some slew-rate improvement on the input. Maybe look at the TADD-2 input for inspiration.
The slew-rate adaptation aims to reduce the slew-rate as being the major impact on noise, but the inputs inherent noise then needs to be handled. This is both the samplers/DFF jitter and the other signals jitter.
Cheers, Magnus _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
