Intel QX9775 EU80574XL088N Data Sheet

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Due to its large number of transistors and high internal clock speeds, the processor 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.

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 

). 

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. 

The processor 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.