Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Fast Transient Burst Signal Filter

Status
Not open for further replies.

BasePointer

Full Member level 2
Joined
Jul 3, 2002
Messages
130
Helped
6
Reputation
12
Reaction score
3
Trophy points
1,298
Location
TURKEY
Activity points
955
transient/burst

How can I suppress 4kV, 2.5kHz and 2kV, 5kHz burst signals?
I'm using three 1mH, 10nF LC filters but my circuit is still influenced, all digital lines in my circuit is changing.
How can I find the spectrum of the burst signal ? I want to see the signal in frequency domain to make proper filter.

Thanks
 

Moss

Full Member level 3
Joined
Jul 24, 2001
Messages
170
Helped
9
Reputation
18
Reaction score
2
Trophy points
1,298
Activity points
1,631
fast transient burst filter

How can I find the spectrum of the burst signal ?
With digital spectrum analyser. probably :). But in transcients are wide bandwith in general You can't use some notch filter to suppres them.

I think that you shoud first reexamine grounding, coupling and isolation of your digital circuit. With proper design you can significantly increase noise immunity.

Give us some detail, if you want further assitance.
 

pattyb

Newbie level 6
Joined
Sep 26, 2001
Messages
12
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,281
Activity points
26
A Fast transient burst individual pulse has a 5 ns rise time for a duration of 50ns.
The energy is weak but the resulting frequency spectrum is very wide with harmonics > 200MHz.
There is no doubt you would see that on a spectrum analyzer but that would be a little help.
You can also hear them with a simple AM radio receiver tuned in any SW frequency.
Dont forget that it is a Common Mode signal and that it will return to ground by the easiest way. You'd better dont let him choose its way.
It propagate using every little capacitive path. To fight it, an efficient ground plane and best equipotentiality as possible is the right way to go.

When filtering is necessary, usually a little capacitor to ground plane ( eg 1nF ) will do the job.


Good luck
 

    BasePointer

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top