Intel D525 AU80610006225AA User Manual

Product codes
AU80610006225AA
Page of 79
Datasheet
37
Electrical Specifications
4
Electrical Specifications
This chapter contains signal group descriptions, absolute maximum ratings, voltage 
identification and power sequencing. The chapter also includes DC and AC 
specifications, including timing diagrams.
4.1
Power and Ground Balls
The processor has V
CC*
 and V
SS 
(ground) inputs for on-chip power distribution. All 
power balls must be connected to their respective processor power planes, while all V
SS
 
balls must be connected to the system ground plane. Use of multiple power and ground 
planes is recommended to reduce I*R drop. The V
CC
 balls must be supplied with the 
voltage determined by the processor Voltage IDentification (VID) signals.
4.2
Decoupling Guidelines
Due to its large number of transistors and high internal clock speeds, the processor is 
capable of generating large 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 current during longer lasting changes in current demand (for example, coming 
out of an idle condition). Similarly, capacitors act as a storage well for current when 
entering an idle condition from a running condition. To keep voltages within 
specification, output decoupling must be properly designed.
Caution:
Design the board to ensure that the voltage provided to the processor remains within 
the specifications. Failure to do so can result in timing violations or reduced lifetime of 
the processor.
4.2.1
Voltage Rail Decoupling
The voltage regulator solution needs to provide:
bulk capacitance with low effective series resistance (ESR).
a low path impedance from the regulator to the CPU.
bulk decoupling to compensate for large current swings generated during power-
on, or low-power idle state entry/exit.
The power delivery solution must ensure that 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 guide.