ICS1893AFLF Datasheet, PDF (111/136 Pages) Integrated Device Technology – 3.3-V 10Base-T/100Base-TX Integrated PHYceiver™

ICS1893AF Data Sheet - Release
Chapter 10 DC and AC Operating Conditions
10.3 Recommended Component Values
Table 10-3. Recommended Component Values for ICS1893AF
Parameter
Oscillator Frequency
10TCSR Resistor Value
100TCSR Resistor Value
LED Resistor Value
Minimum
Typical
–
25
–
2.00k
–
See Figure 10-1
510
1k
Maximum
–
–
–
10k
Tolerance
± 50 ppm †
1%
1%
–
Units
MHz
Ω
Ω
Ω
† There are two IEEE Std. 802.3 requirements that drive the tolerance for the frequency of the oscillator.
• Clause 22.2.2.1 requires the MII TX_CLK to have an accuracy of ± 100 ppm.
• Clause 24.2.3.4 is more stringent. It requires the code-bit timer to have an accuracy of 0.005% (that is, ±50 ppm).
Figure 10-1. ICS1893AF 10TCSR and 100TCSR
Typical Board Layouts
10TCSR and 100TCSR Bias Resistors
VDD
14
VDD
ICS1893AF
10TCSR
15
12.1 KΩ 1%
100TCSR
16
10TCSR
2.0KΩ 1%
100TCSR
1.54KΩ 1%
Note:
1. The VDD connection to the 12.1K resistor can connect to any VDD.
ICS1893AF, Rev. D 10/26/04
Copyright © 2004, Integrated Circuit Systems, Inc.
All rights reserved.
111
October, 2004