User`s manual

DIGITAL-LOGIC AG MSMP5 / P3 SEN/SEV Manual V1.6A

2.13 High frequency Radiation (to meet EN55022/EN61000)

Since the PC/104 CPU modules are very high integrated embedded computers, no peripheral lines are pro-

tected 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:

Keyboard: KBCLK, KBDATA, VCC

Mouse: MSCLK, MSDATA, VCC

COM1/2/3/4: All serial signals must be filtered

LPT: All parallel signals must be filtered

CRT: red,blue,green, hsynch, vsynch must be 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 sure 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. For stackthrough applications:

Place on each peripheral signal line, they are going outside, a serial inductivity and

after the inductivity a capacitor of 100pF to 1000pF to ground.

In this case, no filtered connectors are needed. Place the filter directly under or

behind the onboard connector.

Serial Inductivity: TDK HF50ACB321611-T 100Mhz, 500mA, 1206 Case

Ground capacitor: Ceramic Capacitor with 1000pF

Power supply:

Use a currentcompensated dualinductor on the 5V supply

SIEMENS B82721-K2362-N1 with 3.6A , 0.4mH