[time-nuts] Fw: HP 1820-0313 4.2V Logic (Flip-flop)

[Dave M]

Dave M wrote:
> Poul-Henning Kamp wrote:
>> --------
>> In message <1580810140.741428.1494966823210 at mail.yahoo.com>, Ulf
>> Kylenfall via time-nut s writes:
>> 
>>> That the 1820-0313 is unobtanium I can understand.Has anyone created
>>> an equvalent based on discretesor is there a suitable SMD "single"
>>> flip-flop like single gatesthat could be suitable?
>> 
>> I did a divider board for the LED clock:
>> 
>> http://phk.freebsd.dk/hacks/HP5065A/20160112_working_clock/index.html
> 
> The 1820-0313 is a Fairchild 931HC or Motorola MC931G DTL clocked
> flipflop. I think if you toy with a TTL or CMOS JK-flipflop; it
> should work with no issues.  The only caveat would be the 4.2V Vcc. 
> The DTL logic was spec'ed to run at 5V, same as TTL, but don't know
> how TTL logic would work at 4.2V. .
> You might find a 3.3V flipflop and zener the 4.2V Vcc down to 3.3V
> and build it all onto a small piece of perfboard.
> 
> I've attached a copy of the pertinent pages from my old Motorola
> databook (1966 Motorola Semiconductor Handbook) directly to Poul.
> 
> Dave M


Oops... I meant to say that I sent a copy of the datasheet to the OP

Dave M