I have a problem, RS232 signal causing interference to audio line, how to solve this problem? did some one experience to solve this? please, share...
thanx.
Are you sure?
Ferrite rings are effective at radio frequencies - I don't think they'd make any (noticeable) difference at audio frequencies, would they?
I never heard a digital signal disturbing a analog signal when they r on separate lines.
If you think it can,can any one explain me one scenario?
I know that digital signal can cause interference to analog signal when they on a single PCB...because of debouncing effect.
In your case take the grounding measures properly it may work out.
"I never heard a digital signal disturbing a analog signal when they r on separate lines."
Have you never heard the interference caused by a GSM phone placed near to audio equipment?!
The audio output from laptop PCs is renowned for being poor due to interference from all that close-peoximity high-speed digital stuff crammed into such a small space!
It is, in fact, very common indeed - which is why every text on sensitive analogue design will tell you to keep the sensitive analogue signals well away from digital signals. And keep the power supplies well separated.
"If you think it can,can any one explain me one scenario?"
You gave your own example:
"I know that digital signal can cause interference to analog signal when they on a single PCB"
You say you know it happens - why do you need any more examples?!
"because of debouncing effect"
Absolutely nothing whatsoever to do with debouncing!
Maybe "debouncing" is not the right term for what you're thinking of - please exaplain in detail.
"In your case take the grounding measures properly it may work out."
Yes, proper grounding is certainly necessary - though it alone may not be sufficient.
Due to GSM phones interefrence will always be there as they are wireless.
Coming to laptop internally there are tracks on PCBs so intereference will be there.It best explains my point about the interference due to lay outs.
Debouncing mean the signal altering between the ground and transmission line.
But the question was interference between wired signals i want example for that type of scenario....
"But the question was interference between wired signals"
What are PCB traces (tracks) if not "wired signals"?!
The mechanisms of interference between tracks on a PCB are identical to those between signals in cables!
If you place a long microphone cable close to a long mains cable you will get interference between them - in the form of a mains-frequency "hum" on the audio signal. If the mains cable is connected to loads like fluourescent lamps or thyristor dimmers, you will also get all sorts of other nasty noises!
Screening the microphone cable and using low-impedance, balanced signals helps to minimise the susceptibility of the audio to interference...
"Debouncing mean the signal altering between the ground and transmission line."
No - I think you mean "decoupling"?
Or maybe "ground-bounce"?