[time-nuts] low power divide by 5

[jimlux]

On 6/30/20 5:04 PM, Richard (Rick) Karlquist wrote:
> 
> On 6/30/2020 3:47 PM, dschuecker wrote:
>> Hi,
>>
>> a divide by five should possible with a synchronous state-machine made 
>> of 3 ( sufficiently fast-) JK-FlipFlops.
>>
>> All 3 FFs are clocked with the input freq. , the outputs of the FFs 
>> are fed back to the the JK-inputs,  the divided freq. is output of one 
>> of the FFs.
>>
>>
>> Detlef
>>
> 
> 
> Nice ideas, but JK flip flops seem to have become extinct in
> newer logic families.
> 
> It might be interesting to see what could be done
> using one of those programmable logic devices (PLD).
> 
>


Oddly, those too are hard to find.. The venerable 22V10 (which I used in 
the 1980s) is still available (as the ATF22V10 from Microchip/semi), 
targeting the military market (probably to "build to print" stuff 
designed in the 80s and 90s)

But it's interesting - lots of 20k gate FPGAs and such, not so many 
"dozen flip flops and 2 dozen gates" devices.