VSC8201DL

Rev. 1.6.3 - 9/29/04

VITESSE - CONFIDENTIAL & PROPRIETARY - DO NOT COPY WITHOUT PERMISSION

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In addition, a ferrite bead should be used to isolate each analog supply from the rest of the board. The bead should be placed in series

between the bulk decoupling capacitors and the local decoupling capacitors.

Figure 3: Power Supply Decoupling Schematic

The beads should be chosen to have the following characteristics:

•

Current Rating of at least 150% of the maximum current of the power supply.

•

Impedance of 80 to 100W at 100Mhz.

Recommended beads are:

•

Panasonic EXCELSA39 or similar.

•

Steward HI 1206N101R-00 or similar.

Note:Place vias close to or under neath the capacitor pads for

low inductive path and higher heat dissipation rate.

0.1 uF

.

Figure 2: Local High-Frequency decoupling Capacitor Layout - LBGA package