Hi
I have a frame of 14 pulses in duration of 252 micro second so each pulse is 180nano second .Pulses are in 3level(+5 0 -5).


...... 90ns

45ns ....... 45n 45n.......45ns

..........................90ns

What is the way to have this speed?

 

So far none of your posts make any sense in English. May i suggest you have a friend with a better grip of English to help.

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Sorry but your posts make as much sense as my ramblings above

 

I kind of understand what you're asking for...but you don't have enough details. Could you re-write/re-word your questions in a couple more different ways?

 

Hi dear

Thank you for your attention.The picture I have attached is some pulses of one frame.You can see pulses duration in this picture.I found that I have to use D/A in output of micro to have the output in 3 states ( +5 0 -5).
But dont know that if I am able to reach this speed or not with what type of micro.And what can be the simplest program.

regard

Attached Thumbnails

 

 

One frame that is 252us long divided into 14 pulses is 18us per pulse, not 18ns. To be 18ns per pulse, the frame has to be 252ns.

 

if understand correct....
You need a microcontroller who, is fast enough, to proccess your signal.
most important , you must take attention to D/A to be that fast.
since D/A most propably will be slower than MCU.

as dknguyen mentiom your pulses must be 18us.

but i also noted that not all pulses have not the same width, ie first is 90(ns ?) second is 45(ns ?) etc.

Anyway to found how fast your D/A must be , you should take smallest pulse , in your case 18(ns ?) , transorf it to Hz ie 1/0.000000018= 55.55 MHz and you found it ,
You D/A must be able to generate MINIMUN 55.55 Million samples per second (aka 55.55msps).

Note that this speed is quite fast, and achieved with realy fast mcu most propably you you will need a ARM based cpu at 60mhz clock rate. propably way more to have time to proccess output too 100/150mhz !?

if it not ns but us(mikrosecond) the its not 55megaherz but 55.55KiloHerz which is possible with vast majority of mcu out there AVR,PIC etc

 

Dear
My totaly frequency is 5.5 MHZ and minimum of each pulse is 90ns and (45ns+45ns for sides of pulse).At least I need a micro that is able to get 90ns.

best regards
fartaj

 

Dude, use a counter and an opamp. It is a prohibitively expensive and complex processor to do such a simple task at that frequency!

Dan

 

a D/A can be as simple as 8 resistors in mcu's output.
and changing output speed in most mcu's is equal to their max speed

many AVR's can be clocked at 20Mhz and able to to 20million instruction per second. such as ATtiny2313 etc.

however also depend on what are you planning to do.
having a signal stored in mcu memory and generating, will be relative easy.

 

and he asked for a repeatable stable output over 25 million times a second.

 

not sure i got you.

but the first post says he has a frame of 14 pulses.

as i understand it there are 14 diffirent "pulses".
needed to be repeated in output.

i als saw from another thread, that he has generate an ASCII based file , with diffirent values from a signal , and wanding to send it from PC to mcu and the generate the sound.

thats why i suggested a mcu.

an AVR can receive data from PC, an ASCII 8bit file for example.
store it his memory,
and then just poke a byte every 3 clock steps (supposing avr has a 16.5mhz clock),
on one of his outputs.
Thats everythink needed.

since a resistor in each mcu pin it is actually a D/A

 

He made no sense in that thread, and he's making none in this one either.

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he said 90nS pulse width.