Help me design a frequency multiplier circuit

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almotions

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Hi,
i want to ask if anyone of you know how to design a circuit which takes in a digital input squarewave with 50%duty cycle with frequency f,and output a square wave with 2 times the input frequency but half the voltage with 50%duty cycle as well.
Please help.Thanks.

alvin
 

Re: Frequency Multiplier

you need to either use a PLL or you can use two monoshot multivibrators, but you need to know the period before hand.

BRM
 

Re: Frequency Multiplier

A delayed square wave XOR'ed with the original wave will give you doubled frequency.

Check this out.
https://www.edn.com/archives/1997/021797/04DI_01.htm

Regarding half amplitude, that can be done using a simple 2 resistor voltage divider or using an op-amp based attenuator.
 

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    almotions

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Re: Frequency Multiplier

Thanks guys.That's what i need.

Added after 25 seconds:

Thanks guys.It;s just
 

Re: Frequency Multiplier

You may find some more info here:


S.
 

Frequency Multiplier

It possible to do it with pure logic even with autotune when freq change . You will need much high clock (more - better resolution). The one counter measures half period another is preload abd sub type gets couted pulses div by 2 (skip MSB bit from first counter) from the first counter. The both sum of insig rise fall and sub counter output mixed goes to d trigger to get 50 due .
Another approach is analog - input freq get multiplied by 2 (non strict 50 percent due ) and sawtooth is generated , then comparator with auto adjustable (adjusted to due rate) threshold will get 50 due cycle square.
 

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