I want to make nanosecond clock timer as a 64-bit counter. There is a scheme (4-bit): enter image description here

I am trying to find JK-trigger, or other, that can work with 300 Mhz clock speed, at least, i.e. 3.3 ns at most, but I am finding only ICs with tens or even hundreds nanoseconds precision, like HCF4027BE.

Do JK (or other triggers) with less than 3.3ns delay exist?

Is there other solutions for nanosecond counter?

I found out about ECL logic, that seems to be fast.

How about make own triggers (flip-flops), from ECL components?

Well, seems like there are stuff, I need

enter link description here

There are, for example D-triggers (flip-flops) with less 3 ns propagation time.

I can use, for example, this one for 64-bit counter with D-trigger, right?

  • \$\begingroup\$ Use a parametric search with some major manufacturers. Don't forget to look for counters as well as bare flip flops. \$\endgroup\$
    – greybeard
    Jun 4, 2023 at 16:50
  • \$\begingroup\$ (One alternative to ripple counters are synchronous counters. A by-10 prescaler is easy with a Johnson counter.) \$\endgroup\$
    – greybeard
    Jun 4, 2023 at 16:52
  • \$\begingroup\$ @greybeard, distributors often just put IC title, like HCF4027BE, instead of full specification, or at least pointing that it is a JK-trigger \$\endgroup\$ Jun 4, 2023 at 16:57
  • \$\begingroup\$ @greybeard, can You please tell how the value I am asking about is in English. I mean trigger delay, how it called correctly? \$\endgroup\$ Jun 4, 2023 at 16:59
  • \$\begingroup\$ Problem: I don't know what a trigger delay may be. Clock input to output? Clock cycle length? 300 MHz makes a somewhat challenging clock frequency, compare to device's maximum clock frequency \$f_{max}\$. \$\endgroup\$
    – greybeard
    Jun 4, 2023 at 17:04

1 Answer 1


Dedicated counters or JK flip-flops can be found only in older CMOS families, which are slow. For the shortest propagation delays, you have to look for D flip-flops in modern low-voltage families like AUC, e.g., SN74AUC74 with 350 MHz (with a 2.5 V supply).


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