Intel 810A3, Design Manual

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Layout and Routing Guidelines
4-30 Intel
®
810A3 Chipset Design Guide
4.14.4 Recommendation for Intel Platforms
The following tables are examples of components that meet Intel’s recommendations, when
configured in the topology presented in
Figure 4-29 .
To satisfy damping requirements, total series resistance in the filter (from V
CC
CORE
to the top plate of
the capacitor) must be at least 0.35
Ω
. This resistor can be in the form of a discrete component, or
routing, or both. For example, if the picked inductor has a minimum DCR of 0.25
Ω
, then a routing
resistance of at least 0.10
Ω
is required. Be careful not to exceed the maximum resistance rule
(2
Ω
). For example, if using discrete R1, the maximum DCR of the L should be less than
2.0 - 1.1 = 0.9
Ω
, which precludes using some inductors.
Other routing requirements:
•
C should be close to PLL1 and PLL2 pins, < 0.1
Ω
per route. These routes do not count
towards the minimum damping R requirement.
•
PLL2 route should be parallel and next to PLL1 route (minimize loop area).
•
L should be close to C; any routing resistance should be inserted between V
CC
CORE
and L.
•
Any discrete R should be inserted between V
CC
CORE
and L.
Table 4-8. Inductor
Part Number Value Tol SRF Rated I DCR
TDK MLF2012A4R7KT 4.7 uH 10% 35 MHz 30 mA 0.56
Ω
(1W max)
Murata LQG21N4R7K00T1 4.7 uH 10% 47 MHz 30 mA
0.7
Ω
(±50%)
Murata LQG21C4R7N00 4.7 uH 30% 35 MHz 30 mA 0.3
Ω
max
Table 4-9. Capacitor
Part Number Value Tolerance ESL ESR
Kemet T495D336M016AS 33 uF 20% 2.5 nH 0.225
Ω
AVX TPSD336M020S0200 33 uF 20% TBD
0.2
Ω
Table 4-10. Resistor
Value Tolerance Power Note
1
Ω
10% 1/16 W
Resistor may be implemented with trace resistance, in which
discrete R is not needed
Figure 4-31. Using Discrete R
L
C
<0.1 ohm route
PLL2
PLL1
370-Pin
Socket
<0.1 ohm route
R
VCC
C O R E
Discrete Resistor