AN83REV1
33
CS8900 Technical Reference Manual
2.4 Layout considerations for the
CS8900
The CS8900 is a mixed signal device hav-
ing digital and analog circuits for an Ether-
net communication. While doing the PCB
layout and signal connections, it is impor-
tant to take the following precautions:
a) Provide a low inductive path to reduce
power and ground connection noise.
b) Provide proper impedance matching
especially to the Ethernet analog signals.
c) Provide low inductive path, wider and
short traces, for all analog signals.
It is important that a PCB designer follow
suggestions made in this document for
proper and reliable operation of the
CS8900. These guidelines will also benefit
the design with good EMI test results.
2.4.1 General guidelines
Figure 2.4.1 shows component placement
for an ISA COMBO Ethernet adapter card
using a CS8900. The placement of the
CS8900 should be such that the routes of
the analog signals and the digital signals
are not intermixing. No signal should route
beneath the CS8900 on any plane.
2.4.2 Power supply connections
The CS8900 has 3 analog and 4 digital
power pin pairs (Vcc and GND). Addi-
tional ground connections are provided.
Each power pin pair should be connected to
a 0.1
µ
F bypass capacitor. Connect the
extra ground pins directly the ground plane.
Содержание CRYSTAL LAN CS890
Страница 26: ...26 AN83REV1 CS8900 Technical Reference Manual Figure 2 2 9 CRD8900 Top Side Routing ...
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Страница 36: ...36 AN83REV1 CS8900 Technical Reference Manual Figure 2 4 2 Ground connection Top layer of two layer Combo Card ...
Страница 40: ...40 AN83REV1 CS8900 Technical Reference Manual Figure 2 4 6 Component top side of four layer board ...
Страница 41: ...AN83REV1 41 CS8900 Technical Reference Manual Figure 2 4 7 5V Plane of four layer board ...
Страница 42: ...42 AN83REV1 CS8900 Technical Reference Manual Figure 2 4 8 Ground Plane of four layer board ...
Страница 43: ...AN83REV1 43 CS8900 Technical Reference Manual Figure 2 4 9 Solder side bottom of four layer board ...