How to generate 5Mhz Pulse with Arduino

Hi Everyone,

I need your help, I want to generate 5Mhz pulse, is arduino able to do that ?

Thank you in Advance Ghild

Is that a pulse at a repetition rate of 5MHz? So up for 100nS and down for 100nS?
How accurate does this need to be?
The arduino only has. 16MHz clock so that does not fit nicely into 5MHz so I would say no you can’t do that with an Arduino Uno.
You could however do it with a Due.

Hi Mike,

Why I should to use due ? the clock speed of uno still higher than 5Mhz , right ?

It is no need to accurate

With a 16MHz clock, each clock period is 62.5ns (1/16e6). That means that the simplest operations happen in 62.5ns and that more complex operations happen in multiples of 62.5ns.

You want a 100ns period. Do you see any issues with that?

You still have not described what it is you want.

5MHz is a frequency, not a pulse.

What is it you actually want? If you want a pulse, how long, what attack and decay? By what do you want it to be triggered? How often?

It actually makes it a lot easier if you explain why you want it - for what purpose?

Paul__B: You still have not described what it is you want. 5MHz is a frequency, not a pulse. What is it you actually want? If you want a pulse, how long, what attack and decay? By what do you want it to be triggered? How often? It actually makes it a lot easier if you explain why you want it - for what purpose?

Okay I searching on Google what you mean about "5MHz is a frequency, not a pulse." is your mean like this parameter : 1. Pulse duration 2. Spatial pulse length 3. Pulse repetition period 4. Pulse repetition frequency 5. Duty factor

I want drive 5Mhz ultrasound transducer .

[quote author=Jack Christensen link=topic=221759.msg1611076#msg1611076 date=1393506684] With a 16MHz clock, each clock period is 62.5ns (1/16e6). That means that the simplest operations happen in 62.5ns and that more complex operations happen in multiples of 62.5ns. You want a 100ns period. Do you see any issues with that? [/quote]

I Think Arduino alone is difficult to generate that, maybe need addtional circuit like Logic gate , do you know about it ?

You still have to drive external logic chips, trigger them, whatever, and with a 62.5 nanosecond cycle time, you can't get anywhere even close to 5 MHz.

If you hook an external circuit into the 16 MHz clock of the Arduino (and do it without messing up the waveform), you can dvide it by three and get 5.333 MHz, which may or may not be close enough for your transducer.

Of course, you could always use a 5 MHz crystal, amplify it, and use external logic to gate it to apply to your transducer.

Or you could use a Due.

lar3ry: You still have to drive external logic chips, trigger them, whatever, and with a 62.5 nanosecond cycle time, you can't get anywhere even close to 5 MHz. If you hook an external circuit into the 16 MHz clock of the Arduino (and do it without messing up the waveform), you can dvide it by three and get 5.333 MHz, which may or may not be close enough for your transducer. Of course, you could always use a 5 MHz crystal, amplify it, and use external logic to gate it to apply to your transducer. Or you could use a Due.

Do you know how to design external logic ? or reference to design it ? If possible, I do not want using Microcontroller as trigger, I want use IC 555 ... But for prototype I want use Arduino..

555 is too slow, STM claims 500 kHz at max. You should check out 74HC4046

can you post a link to a data sheet ?

ultrasonic transducers are used all the time and as you can see, there is no simple answer for your project. maybe there is some more data on the data sheet that would reveal the answer.

5mhz would need a separate device, or may be part of the transducer internal circuit. the data sheet would help us help you.

Magician: 555 is too slow, STM claims 500 kHz at max.

But he didn't say that he said:-

I do not want using Microcontroller as trigger, I want use IC 555 .

As a trigger it is fine but generating a 5MHz is something for external circuits.

But he didn't say that he said:-

I do not want using Microcontroller as trigger, I want use IC 555 .

As a trigger it is fine but generating a 5MHz is something for external circuits.

the full quote is

Do you know how to design external logic ? or reference to design it ? If possible, I do not want using Microcontroller as trigger, I want use IC 555 ... But for prototype I want use Arduino.

but you should know that often the end result is stated and the path is not understood. many times, the path is a well traveled one that the OP is not aware of.

the data sheet will reveal if anyone is on the right path to the end result.

the full quote is

So what does the full quote give you that the extract does not?

but you should know that often the end result is stated and the path is not understood. many times, the path is a well traveled one that the OP is not aware of.

This is a technical forum not a philosophical one. Irrespective of awareness he wants to control an ultrasonic transducer. There are two aspects to this:- 1) To generate 5MHz to drive the transducer. 2) To control the pulse modulation of this transducer. You can do 2 with a processor or a NE555 you can do 1 with neither of these.

Grumpy_Mike:

the full quote is

So what does the full quote give you that the extract does not?

.....prototype I want use Arduino..

Which brings us back to the first post

I want to generate 5Mhz pulse, is arduino able to do that ?

everything other than 'no, you cannot' is philosophical, no ?

Hi Guys :)

Maybe to Generate 5Mhz , I will use Microcontroller to generate wave in Khz , then the frequency will be multiplied using Multiplier IC (like : http://www.torex.co.jp/english/products/detail.php?id=207) and then will be amplify using Mosfet circuit and the Output will drive the transducer.

and for receiver, I will use low-noise amplifier, then the frequency will divided using Divider IC, and to know Time from First pulse from Tx and First incoming Echo, I will use threshold circuit , they will be calculated on Microcontroller for thickness of the Under test material

Please some Advise Thank you

The problem with that PLL is that it is a custom design where they make it especially for you so it is unlikely you will be able to buy itis small quantities. The point about PLLs in general is that they take time to settle so they are not suitable for generating bursts of oscillation like you want.

What is wrong with a 5MHz crystal and control the bursts with a logic gate on the output?

Grumpy_Mike: The problem with that PLL is that it is a custom design where they make it especially for you so it is unlikely you will be able to buy itis small quantities. The point about PLLs in general is that they take time to settle so they are not suitable for generating bursts of oscillation like you want.

I do not Understand what u mean

Grumpy_Mike: What is wrong with a 5MHz crystal and control the bursts with a logic gate on the output?

The problem is I have not any experience to build that, That why I post this topic

I do not Understand what u mean

I mean that a PLL that is the sort of chip you linked to is no good for what you want.

You have no experience in building a PLL circuit either and they are more difficult to build.

So What is the solution ? :~ :sweat_smile: