100X frequency multiplier

dante_clericuzzio

Joined Mar 28, 2016
246
Is there any circuit that is capable of multiply frequency by 100 times. So far i search there is 10 X using CD4046

dl324

Joined Mar 30, 2015
16,911
Just add another divide by 10 counter.

dante_clericuzzio

Joined Mar 28, 2016
246
Just add another divide by 10 counter.
I don't understand ..you meant add 10 circuit like that so it become 10 x 10 = 100 times? that would be tedious work i guess

dl324

Joined Mar 30, 2015
16,911
I don't understand ..you meant add 10 circuit like that so it become 10 x 10 = 100 times? that would be tedious work i guess
That's the way a PLL works.

Two divide by 10 counters cascaded gives 100X.

Joined Feb 20, 2016
4,476
that would be tedious work i guess
I don't understand it being tedious.
It is not 100 more chips, just another one.

dante_clericuzzio

Joined Mar 28, 2016
246
That's the way a PLL works.

Two divide by 10 counters cascaded gives 100X.
Ok if that's the only way i will try although it could be tedious work...but i am just wondering like the modem-router that i opened up the circuit looks very minimal and probably using 1 IC with plenty of pins to do that -- I am just guessing

dante_clericuzzio

Joined Mar 28, 2016
246
I don't understand it being tedious.
It is not 100 more chips, just another one.
You meant 1 to 10 then 10 to 100? that's logical ....i though it would like another combination of each circuit my thought was 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 + 10 so it's 10 circuits of the same kind.

Now that you are saying 1 to 10 then using another chip to multiple this to 100 that would be 3 chip ...now i got it

Joined Feb 20, 2016
4,476
Most CPUs and micro controllers have Phase locked Loops inside them with thousands of transistors, You are trying to build a PLL with some quite simple chips. There are specific PLL chips you can get that have many stages of dividers on them.
Adding another 7490 divide by 10 is no big deal.
If you don't want to do that, use one of these...
https://assets.nexperia.com/documents/data-sheet/74HC_HCT390.pdf

dante_clericuzzio

Joined Mar 28, 2016
246
I built an RF synthesizer years ago using some of these...
https://assets.nexperia.com/documents/data-sheet/74HC_HCT193.pdf
If you put a few of these in series and then preset the count on each timeout, you can have divide by lots
Would you be kind to share working schematic that generate up to 2.6 Ghz frequency? hehe

and by the way when you are saying this

"Adding another 7490 divide by 10 is no big deal." --- why do you mention divide when we want to multiply i am just curious there must be a reason

Joined Feb 20, 2016
4,476
You are actually dividing the "feedback" signal to the Phase Comparator. It generates a signal to move the Voltage Controlled Oscillator (VCO) so a sample from the VCO matches the reference frequency. So if the VCO sample frequency is divided by 2, the VCO is driven to twice the reference frequ. Likewise, if the VCO sample frequency is divided by 100, the VCO is driven to 100 x the reference frequency.
And yes, this is how a lot of circuits generate the 2.6Ghz frequencies.
often with mixers, tuned frequency multipliers and PLLs.

bertus

Joined Apr 5, 2008
22,276
Hello,

Did you see the synthesizer schematic in the 4046 datasheet.

Bertus