Crazy Inventor

Hello to all
If any one is familiar with the CD4059A Divide by N chip (programable counter)
i would very much appreciate your help as i don't understand the manufactures data sheets, i need to divide by 1000.
If any one could help with actual pin connections to derive at this factor it would be fantastic as i have come to a halt with my latest project.

Nigel Goodwin

To divide by 1000 just use 3 divide by ten chips in series, no need to use a divide by N chip unless you're looking for non-standard values.

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boncker

Also you can use a CD4040 with the outputs Q9, Q8, Q7, Q6, Q5 and Q3. All these outputs you can input them in a AND logic port. But, in this case you need to use 2 chips, on for the CD4040 and other with the logic ports.
In other words, with CD4040 you can divide a clock for any number up to 4096, but using AND ports after the 4040.

Good luck!

audioguru

A CD4040 is a ripple counter. Its outputs do not occur at the same time like a syncronous counter. Therefore when gated together the output of the gate has many glitches.

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Uncle $crooge

Russlk

What a complicated chip! Do you have to use it?

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philba

you can use a ripple counter if you are careful and compute the worst case stabilization time for the pattern you wish to use. for 1000, look at it as binary - 1111101000.

For example, the 74HC4040 at 4.5V has an interstage propagation max of 31 nS so worst case for 10 bits is 310nS. It turns out, though, for that bit pattern, the stabilization time is for only 4 bits or 124 nS. If your clock period is more than 248 nS (4 mhz or lower) then you can take the output value on the falling edge of the clock with no glitches. assuming a square wave clock. You do need to factor in reset propagation.

if you use a real CD4040, then the numbers change but unless you need >5V operation, I'd stick with the HC series.

of course, an 8 pin PIC could do this.

oldtimer

Use 3x 4017 decade counter in series.

oldtimer

If you need a clock and not worried about it being exact use an inverter with a resistor across it and a cap. on the input to ground. The time is CxR and the freq. is 1/CR. If it's 6 in a chip connect them in series or parallel to the output of the oscillator if you require more power.

audioguru

It better be Cmos and it better be Schmitt-triggers. An ordinary inverter won't oscillate with just a resistor and capacitor. A Cmos Scmitt-trigger oscillator makes a pretty good VCO when you change its supply voltage.

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Paul Obrien

what frequency are you trying to divide, at VHF+ you will probably need a more specialised IC divider.

Russlk

The CD4059 is only good to 3 mHz.

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mcs51mc

I ever used one several years ago before I started with µP
That project (fuel consumption of oil burner) is also with µP now
If you can wait until tomorrow I will post more information tomorow...

Crazy Inventor

Hello Paul Thank you for your help The frequency is variable 15khz to 20khz
I have been trying to display my circuit but have not worked how to put it on yet.

Crazy Inventor

Yes i can wait that would be great
Thank you.

oldtimer

Try using a 4011 nand gate,I've done it many a time,I've numerous devices I've built over the years using these. If you don't want a 50/50 pulse stick a diode in series with another resistor across the other resistor and the ratio of the two will give you the ratio of the pulses. The polarity of the diode determines the period between high and low.

With a nand gate you can have two running at the same time by using both inputs instead of connecting them together.