ICS1893CK ICST [Integrated Circuit Systems], ICS1893CK Datasheet - Page 100

• Manufacturer Part Number: ICS1893CK
• Description: 3.3-V 10Base-T/100Base-TX Integrated PHYceive
• Manufacturer: ICST [Integrated Circuit Systems]

9.3 Recommended Component Values *
ICS1893CF, Rev. F, 03/01/07
VDD
Note:
1. The bias resistor networks set the 10baseT and 100baseTX output amplitude levels.
2. Amplitude is directly related to current sourced out of the 10TCSR and 100TCSR pins.
3. Resistor values shown above are typical. User should check amplitudes and adjust for transformer effects
4. The VDD connection to the 18.2K resistor can connect to any VDD. The 18.2K resistor provides negative
Typical Board Layouts
10TCSR and 100TCSR Bias Resistors
Table 9-3. Recommended Component Values for ICS1893CF
† There are two IEEE Std. 802.3 requirements that define the tolerance for the frequency of the oscillator.
Figure 9-1. ICS1893CF 10TCSR and 100TCSR
* For backward compatibillity, refer to the “1893C Alternate Schematic” application note.
Oscillator Frequency
10TCSR Resistor Value
100TCSR Resistor Value
LED Resistor Value
feedback to compensate for VDD changes. Lowering the 18.2K value will lower the 100baseT amplitude.
•
•
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).
ICS1893CF Data Sheet - Release
18
VDD
Parameter
2.43KΩ 1%
10TCSR
Copyright © 2007, Integrated Device Technology, Inc.
Minimum
510
–
–
–
10TCSR
19
ICS1893CF
See
All rights reserved.
Typical
Figure 9-1
2.43k
100
25
1k
18.2KΩ 1%
1.82KΩ 1%
100TCSR
Maximum
10k
Chapter 9 DC and AC Operating Conditions
–
–
–
100TCSR
20
± 50 ppm †
Tolerance
1%
1%
–
Units
MHz
Mar. 2007
Ω
Ω
Ω