Pulse generator on any Edge Detect

[RodSTAR]

Hello guys, I need a hopefully a single chip (or circuit if necesary) that meets the following requirements.

The following characteristics:
-voltaje: TTL (DC 3v3 / 5v)
-input: a pulse signal
-action: detect any high or low edge (of input pulse)
-output: a full pulse for each detected edge (of input pulse)
-other: the width of output pulse should be configurable example: example 1 uS (variable via pot)
-frequency: 50kHz at least

it sounds to me like a 555 can do that, really not sure. I'm a software guy, not an electronics yet.

I attached an image to make it clearer...

 

[ronsimpson]

see picture. click on picture

 

[RodSTAR]

thanks Ron,
wow! that looks like black magic... xP
So if I place a POT in place of R1 I can vary the high width time (period)??

PD: Should a 4070 also work instead? (CMOS Quad Exclusive-OR Gate)

 

[crutschow]

Yes, you can use a pot to vary the pulse width, and yes you can use a 4070. The 4070 has a high input impedance so you can use a larger resistor and a smaller capacitor for the same pulse as compared to the 74LS86.

 

[RodSTAR]

very nice, thanks crutschow,
but, which formula should I use to get the values of capacitor and resistance to get a determined high time?
Example: 1uS

 

[crutschow]

very nice, thanks crutschow,
but, which formula should I use to get the values of capacitor and resistance to get a determined high time?
Example: 1uS

With a typical logic threshold for the 4070, the pulse width should be somewhat less that the RC time constant. Thus, for example with C= 100pF you would want R to be 10k ohm or a little higher.

Edit: A 50k ohm pot should give you plenty of adjustment range.

 

[RodSTAR]

ok thanx, tommorrow i'll get the parts, test it, and tell you about it, see you...