Intel X5460 AT80574KJ087N Data Sheet

Product codes
AT80574KJ087N
Page of 118
Quad-Core Intel® Xeon® Processor 5400 Series Electrical Specifications
16
2.2
Power and Ground Lands
For clean on-chip processor core power distribution, the processor has 223 V
CC
 (power) 
and 267 V
SS
 
(ground) inputs. All V
CC
 lands must be connected to the processor power 
plane, while all V
SS
 lands must be connected to the system ground plane. The 
processor V
CC
 lands must be supplied with the voltage determined by the processor 
Voltage IDentification (VID) signals. See 
 for VID definitions.
Twenty two lands are specified as V
TT
, which provide termination for the FSB and 
provides power to the I/O buffers. The platform must implement a separate supply for 
these lands which meets the V
TT
 specifications outlined in 
2.3
Decoupling Guidelines
Due to its large number of transistors and high internal clock speeds, the Quad-Core 
Intel® Xeon® Processor 5400 Series is capable of generating large average current 
swings between low and full power states. This may cause voltages on power planes to 
sag below their minimum values if bulk decoupling is not adequate. Larger bulk storage 
(C
BULK
), such as electrolytic capacitors, supply voltage during longer lasting changes in 
current demand by the component, such as coming out of an idle condition. Similarly, 
they act as a storage well for current when entering an idle condition from a running 
condition. Care must be taken in the baseboard design to ensure that the voltage 
provided to the processor remains within the specifications listed in 
. Failure 
to do so can result in timing violations or reduced lifetime of the component. For further 
information and guidelines, refer to the appropriate platform design guidelines.
2.3.1
V
CC 
Decoupling
Vcc regulator solutions need to provide bulk capacitance with a low Effective Series 
Resistance (ESR), and the baseboard designer must assure a low interconnect 
resistance from the regulator (EVRD or VRM pins) to the LGA771 socket. Bulk 
decoupling must be provided on the baseboard to handle large voltage swings. The 
power delivery solution must insure the voltage and current specifications are met (as 
defined in 
). For further information regarding power delivery, decoupling 
and layout guidelines, refer to the appropriate platform design guidelines.
2.3.2
V
TT
 
Decoupling
Bulk decoupling must be provided on the baseboard. Decoupling solutions must be 
sized to meet the expected load. To insure optimal performance, various factors 
associated with the power delivery solution must be considered including regulator 
type, power plane and trace sizing, and component placement. A conservative 
decoupling solution consists of a combination of low ESR bulk capacitors and high 
frequency ceramic capacitors. For further information regarding power delivery, 
decoupling and layout guidelines, refer to the appropriate platform design guidelines.
2.3.3
Front Side Bus AGTL+ Decoupling
The Quad-Core Intel® Xeon® Processor 5400 Series integrates signal termination on 
the die, as well as a portion of the required high frequency decoupling capacitance on 
the processor package. However, additional high frequency capacitance must be added 
to the baseboard to properly decouple the return currents from the FSB. Bulk 
decoupling must also be provided by the baseboard for proper AGTL+ bus operation. 
Decoupling guidelines are described in the appropriate platform design guidelines.