CS8900A-IQZ View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
'CS8900A-IQZ' PDF : 138 Pages View PDF
CS8900A
Crystal LAN™ Ethernet Controller
7.5 10BASE-T WIRING
CS8900A
TXD + Rt
TXD -
Rt
68 pF
0.01 µF
1: 2
RXD+
+
- RXD-
0.01 µF
1:1
Rr
Rr
TD +
1
TD -
2
RJ45
RD +
3
RD -
6
• If a center tap transformer is used on the RXD+ and RXD- inputs, replace the pair of Rr re-
sistors with a single 2xRr resistor.
• The Rt and Rr resistors are ±1% tolerance.
• The CS8900A supports 100, 120, and 150 Ω unshielded twisted pair cables. The proper val-
ues of Rt and Rr, for a given cable impedance, are shown below:
Cable Impedance (Ω)
100
120
150
Rt (Ω)
24.3
30.1
37.4
Rr (Ω)
49.9
60.4
75
• Note: for 3.3V operation the turns ratio on TXD+ and TXD- is 1:2.5, rt is 8Ω for 100Ω cable
and the 68pF cap changes to 560pF.
CIRRUS LOGIC PRODUCT DATASHEET
DS271F4
121
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