Intel 82547EI, Руководство по конструкции

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82562EZ(EX)/82547GI(EI) Dual Footprint Design Guide
5
The values of R1, R2 and R3 must be rated at ±1% tolerance. The selected resistor values must also
ensure that the reference voltage and reference swing voltage tolerance are maintained over the
input leakage specification. A 0.1 µF capacitor (C1 in
Figure 2 ) should be placed within 0.5 inches
to each resistor divider, and a 0.01 µF bypass capacitor (C2 in Figure 2 ) should be placed within
0.25 inches of reference voltage pins. If the length of the trace from the voltage divider to the pin is
greater than 1 inch, place more than one 0.01 µF capacitor near the reference voltage pin. The trace
length from the voltage divider circuit to the CI_REF pins must be no longer than 3.5 inches.
Both the voltage reference and voltage swing reference signals should be routed at least 10mils
wide and spaced at least 20 mils from all other signals.
2.2.2 CSA Port Resistive Compensation
The CSA port uses a resistive compensation signal (CI_RCOMP) to compensate buffer
characteristics for temperature, voltage, and process.
Figure 3. CSA port CI_RCOMP Circuits
Table 4. CSA Port CI_RCOMP Resistor Values
Component Trace Impedance RCOMP Resistor Value RCOMP Resistor Tied To
Intel
®
82547GI(EI) 60
Ω
± 15% R1 = 30.1
Ω
± 1% VCC1.2
R1
1.2V
Intel®
82547GI(EI)
CI_RCOMP