User`s manual

DIGITAL-LOGIC AG MSLB-P5 Manual V0.3
PRELIMINARY 18
2.9 High frequency Radiation (to meet EN55022)
Since the boards are very high integrated embedded computers, no peripheral lines are protected
against the radiation of high frequency spectrum. To meet a typical EN55022 requirement, all periph-
erals, they are going outside of the computer case, must be filtered externaly.
Typical signals, they must be filtered:
Interface: Signals: onboard filter on the MSLB-P5:
Keyboard: KBCLK, KBDATA, VCC onboard filter
Mouse: MSCLK, MSDATA, VCC onboard filter
COM1/2/3/4: All serial signals must be filtered not filtered
LPT: All parallel signals must be filtered not filtered
CRT: red,blue,green, hsynch, vsynch must be filtered onboard filter
Powerlines: +5V, +12V, Ground not filtered
Typical signals, they must not be filtered, since they are internaly used:
IDE: connected to the harddisk
Floppy: connected to the floppy
LCD: connected to the internal LCD
1. For peripheral cables:
Use for all DSUB connector a filtered version. Select carefully the filter specifications.
Place the filtered DSUB connector directly frontside and be shure that the shielding makes
a good contact with the case.
9pin DSUB connector from AMPHENOL: FCC17E09P 820pF
25pin DSUB connector from AMPHENOL: FCC17B25P 820pF
2. Power supply:
Use a currentcompensated dualinductor on the 5V supply
SIEMENS B82721-K2362-N1 with 3.6A , 0.4mH