Frequency Division

[joebloggs]

How can i reduce a 4mhz frequency to a 10hz freq?

[Gazza]

How can i reduce a 4mhz frequency to a 10hz freq?

In the power field we use a drive circuit. This means we rectify the signal, then using an inverter reconstruct the wave at the frequency that is desired.

In a low power application I am not sure what the most efficient method would be.

[hotwaterwizard]

You could use a series of deviders.

[mvs sarma]

Hi
such nice info (thanks Hotwaterwizard)  i do recollect my training days.

perhaps the clock being 4MHz, even CD40 series (CMOS)can work and with llower power consumption. ofcourse the proper pin outs shold be followed.

sarma

[Ughadoo]

How can i reduce a 4mhz frequency to a 10hz freq?

You can also use a multi stage Ripple counter;  every stage will divide the input frequency by 2 and so a 16 stage counter will output a frequency of 61.03515

Some extra logic will be necessary to correct the output and to further divide to 10 Hz.

CMOS Ripple counter datasheets:

CD4020BC.pdf

[audioguru]

With a 5V supply, an ordinary Cmos counter is guaranteed to work with a clock frequency as high as only 1.5MHz. A 74HC counter works at much higher frequencies so use a 74HC90 to divide the 4MHz to 400kHz.
Feed the 400kHz to two CD4518 dual divide-by-10 counters in series for an output of 40Hz. Then use a CD4013 dual flip-flop for exactly 10Hz.
The total is 4 ICs.

[MP]

Joe,
If you have some experience with microcontrollers, you can do this pretty easily. Count the pulses coming in and send a pulse out another pin after every so many counts. As long as you use a micro with a faster clock than 4 Mhz, it will work fine. This is on the same lines as what hotwaterwizard, ughadoo and audioguru suggested but with less parts count.

MP