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cnpdk
07-Dec-10, 22:50
While designing the casing/frame for the AMP11-HV I came to think of EMC properties for these amplifiers.

How well is the PCB-layout regarding EMC properties?

Do I need to make any special considerings regarding EMC properties when making the casing/frame?

Should I expect any problems with unwanted EMC output from the AMP11-HV when running it without a metal shield all around it?

Regards

FFF
07-Dec-10, 23:15
Does this help?
- http://www.41hz.com/forums/content.php?394-EMI-and-Temp.-testing-1
- http://www.41hz.com/forums/content.php?393-EMI-and-Temp.-testing-2
- and (when logged in) http://www.41hz.com/forums/downloads.php?do=file&id=11
- and (when logged in) http://www.41hz.com/forums/downloads.php?do=file&id=5
- all app. notes: http://www.41hz.com/forums/downloads.php?do=cat&id=5

Full shielding means a metal, closed box. (which I don't reaally like, but that's personal)
Most recommendations (from Tripath) apply to be with FCC compliance, probably. (like: slits in box <2mm wide)
If you don't use an aerial antenna around for a radio, you could step down.

Also, it helps a lot to isolate the power-chip (sta517b in your case) from the heatsink (would otherwise radiate).
And, after you have built the amp-module, run it bare, and try with a small portable radio for interference.

BUT: the amp will not fry anything in the surroundings; it is, I believe, well designed.
Maybe you could line the housing with wide, thick alu-tape (like used for air-ducts) on wood.

Others will chip-in on this thread.

V-bro
08-Dec-10, 08:15
I have done extensive measurements (sadly without camera at hand) at very wide spectrum and there are also tons of friends and colleagues using these amplifiers by now and I have NEVER heard anyone complain about interference with anything... These amplifiers measure and perform as clean as a whistle.... :)