Intel 810A3, Руководство по конструкции

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Intel
®
810A3 Chipset Design Guide 3-5
SC242 Processor Design Guidelines
3.6 THRMDP and THRMDN
These traces (THRMDP and THRMDN) route the processor’s thermal diode connections. The
thermal diode operates at very low currents and may be susceptible to crosstalk. The traces should
be routed close together to reduce loop area and inductance. Refer to
Figure 3-2 .
Rule
Length Equalization route these traces parallel ±0.5”
Layer route both on the same layer
3.7 Additional Considerations
•
Distribute Vtt with a wide trace. A 0.050” minimum trace is recommended to minimize DC
losses. Route the Vtt trace to all components on the host bus. Be sure to include decoupling
capacitors. Guidelines for Vtt distribution and decoupling are contained in
AP-907: Pentium

III
Processor Power Distribution Guidelines, Order # 245085.
•
The Vtt voltage should be 1.5V
±
3% for static conditions, and 1.5V
±
9% for transient
condition.
•
Place resistor divider pairs for V
REF
generation at the GMCH component. No V
REF
generation
is needed at the processor. V
REF
is generated locally on the processor. Be sure to include
decoupling capacitors. Guidelines for V
REF
distribution and decoupling are contained in AP-
907: Pentium

III
Processor Power Distribution Guidelines (Order # 245085).
Figure 3-2. Routing for THRMDP and THRMDN
1 -- Maximize (min - 20 mils)
1 -- Maximize (min - 20 mils)
2 -- Minimize
Signal Y
T H R M D P
T H E R M D N
Signal Z