ICS1893BKILF datasheet(107/133 Pages) RENESAS

107 / 133 page

Chapter 9 DC and AC Operating Conditions

ICS1893BF, Rev. F, 5/13/10

May, 2010

107

ICS1893BF Data Sheet Rev. F - Release

9.3 Recommended Component Values

† 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 9-1. ICS1893BF 10TCSR and 100TCSR

Table 9-3. Recommended Component Values for ICS1893BF

Parameter

Minimum

Typical

Maximum

Tolerance

Units

Oscillator Frequency

–

± 50 ppm †

MHz

10TCSR Resistor Value

–

2.00k

–

Ω

100TCSR Resistor Value

–

See Figure 9-1

–1%

Ω

LED Resistor Value

510

10k

–

Ω

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.

4. The VDD connection to the 12.1K resistor can connect to any VDD. The 12.1K resistor provides

negative feedback to compensate for VDD changes. Lowering the 12.1K value will lower the

100baseT amplitude.

5. The ICS1893BF 10baseT amplitude is below the IEEE spec but is adequate for 200m operation. This

is the effect of additional MUXes added for the Auto-MDIX function.

Typical Board Layouts

10TCSR and 100TCSR Bias Resistors

ICS1893BF

VDD

10TCSR

100TCSR

2.0K

Ω 1%

VDD

12.1 K

Ω 1%

10TCSR

1.54K

Ω 1%

100TCSR

ICS1893BKILF Datasheet(PDF) 107 Page - Renesas Technology Corp

ICS1893BKILF Datasheet(HTML) 107 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL