ICS1892
TSD
Chapter 10 DC and AC Operating Conditions
10Base-T/100BIaCseS-TX1I8nt9eg2rated PHYceiver™
10.3 Recommended Component Values
Table 10-3 lists the recommended component values for the ICS1892.
Table 10-3. Recommended Component Values
Parameter
Crystal Frequency
Minimum Typical
Maximum
Tolerance
Units
MHz
Ω
–
–
25
2.0k
7.15k
1k
–
–
50 ppm †
10TCSR Resistor Value
100TCSR Resistor Value
LED Resistor Value
1%
1%
–
–
–
Ω
510
10k
Ω
Note: Do not put bypass capacitors across the 10TCSR or 100TCSR resistors. The bypass capacitor will
cause the bandgap circuit to oscillate.
† There are two IEEE Std 802.3 requirements that drive the tolerance for the frequency of the crystal.
• 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).
ICS1892, Rev. D, 2/26/01
February 26, 2001
© 2000-2001, Integrated Circuit Systems, Inc.
All rights reserved.
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IDT™ / ICS™ 10Base-T/100Base-TX Integrated PHYceiver™
ICS1892
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IDT [ INTEGRATED DEVICE TECHNOLOGY ]
