CDB8952T-IQ View Datasheet(PDF) - Cirrus Logic
Part Name
Description
Manufacturer
CDB8952T-IQ Datasheet PDF : 86 Pages
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CS8952T
CrystalLAN™ 100BASE-X and 10BASE-T Transceiver
ly) on both sides of the TX+/- traces.
CS8952T Pin
Assignment
91 (RX+)
92 (RX-)
81 (TX-)
80 (TX+)
T1 Primary Pin
Assignment
1 (RX+)
2 (RX-)
16 (TX-)
15 (TX+)
T1 Secondary
Pin Assignment
7 (RX+)
6 (RX-)
10 (TX-)
11 (TX+)
RJ-45 Pin Assignment
Adapter/NIC Hub/Repeater
Configuration Configuration
3 (RD+)
1 (RD+)
6 (RD-)
2 (RD-)
2 (TD-)
6 (TD-)
1 (TD+)
3 (TD+)
Table 11. RJ-45 Wiring
• No signal current carrying planes, i.e. no
ground or power plane, should be present un-
derneath the region between the transformer
secondary (network) side and the RJ-45. How-
ever, a chassis plane may be added in this re-
gion to pick up the metal tabs of a shielded RJ-
45. This chassis plane should be separated from
the ground and power planes by at least
50 mils. That is, all other ground and power
planes should be “cookie cuttered” so they are
voided in the area of the chassis plane. Gener-
ally speaking, parts should not cross the moat
except for the transformer.
• Proper termination practices must be used with
all transmission lines, especially if sending/re-
ceiving high speed signals. Series terminations
must be kept close to the source and load termi-
nations close to the load.
• Locate the crystal as close to the CS8952T as
possible, running short traces on the compo-
nent side in order to reduce parasitic load ca-
pacitance.
• Add bulk capacitance at each connector where
power may be supplied. For example, MII pow-
er may be provided at the MII connector and at
a separate connector for test purposes. If so,
and the two connectors are not adjacent, then
the bulk capacitors should be duplicated in each
locations.
• Use wide traces to connect the unused pairs ter-
mination resistors at T1 and the RJ-45 to the
2 KV capacitor or capacitors in order to mini-
mize their lead inductance.
CIRRUS LOGIC ADVANCED PRODUCT DATABOOK
66
DS206TPP2
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