Hi everyone,

I am getting ready to build a frequency divider board for a Z80 game console project. I have a 32MHz active crystal oscillator and want to divide down this to produce the following frequencies that will be used across varying components of the project:

• 32 MHz
• 16 MHz
• 8 MHz
• 4 MHz
• 2 MHz
• 1 MHz

I originally thought that I would be able to use a ripple counter such as the CD4040BE however the IC doesn't support such high frequencies as 32 MHz (The project is powered at 5V also) so I'm looking for an alternative. One caveat is that the project is designed to make use of few and inexpensive parts as it's aimed at amateurs as a hobby project. I suppose that I could combine the CD4040BE for the lower frequencies if I'm able to half the frequency at the higher frequencies.

Many thanks,
RipX

 

You could use a flip-flop frequency divider. Easy and cheap.

 

Welcome to AAC!

74AC4040 will clock at 140MHz.
Note that DIP ICs are harder to find.

https://uk.farnell.com/on-semiconductor/mc74ac4040dg/ic-logic-74ac-counter/dp/1607667

 

If you want a 74xx74 D-type flip-flop in a DIP package, these are available.

https://uk.farnell.com/texas-instruments/sn74ac74n/logic-dual-pos-edg-trg-d-f-f-14dip/dp/3006361

https://uk.farnell.com/texas-instruments/cd74hc74e/ic-flip-flop-2-circuits/dp/3119978

 

You could use a flip-flop frequency divider. Easy and cheap.

Great, I actually already have some CD4013BE stock and so I suppose I should ask, will these function OK up to 32 MHz? Regards

 

CD4013BE will clock at 8MHz guaranteed.

 

Hi,
At the limit at 10MHz.
E

 

Would members here be of the opinion that this would suffice? It seems to provide 8 flip-flops and can be clocked up to 48 MHz at 5V.

74HCT374N

Datasheet: https://pdf1.alldatasheet.com/datasheet-pdf/view/15596/PHILIPS/74HCT374N.html
DIP package: https://www.aliexpress.com/item/1005004551243516.html

 

74xx374 is intended to be used as an 8-bit latch register. This is not want you need.

What you need are individual D-type or J-K flip-flops, or binary counters such as 74xx161, 74xx163, 74xx191, 74xx193.

Here is how you would use 74xx74 as divide-by-2 counters.

 

74xx374 is intended to be used as an 8-bit latch register. This is not want you need.

What you need are individual D-type or J-K flip-flops, or binary counters such as 74xx161, 74xx163, 74xx191, 74xx193.

Here is how you would use 74xx74 as divide-by-2 counters.

View attachment 290992

Got ya! I'll see if I can find any of those in a DIP package. Thank you

 

See post #4.

 

If you don't need the intermediate outputs to be synchronous, you could use a 74HC4024 or 74HC4040 - They have a guaranteed minimum frequency of about 32MHz at 5V, and a typical value of 80MHz