Datasheet

Datasheet 17
Electrical Specifications
3 Electrical Specifications
This chapter describes the electrical characteristics of the processor interfaces and
signals. DC electrical characteristics are provided.
3.1 Power and Ground Pins
The processor has VCC (power), VCCP and VSS (ground) inputs for on-chip power
distribution. All power pins must be connected to V
CC
, while all VSS pins must be
connected to a system ground plane. The processor VCC pins must be supplied by the
voltage determined by the Voltage IDentification (VID) pins.
The signals denoted as VCCP, provide termination for the front side bus and power to
the I/O buffers. A separate supply must be implemented for these pins, that meets the
V
CCP
specifications outlined in Table 5.
3.2 Decoupling Guidelines
Due to its large number of transistors and high internal clock speeds, the processor is
capable of generating large current swings. This may cause voltages on power planes
to sag below their minimum specified values if bulk decoupling is not adequate. Larger
bulk storage (C
BULK
), such as electrolytic or aluminum-polymer capacitors, supply
current 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. The motherboard must be designed
to ensure that the voltage provided to the processor remains within the specifications
listed in Table 5. Failure to do so can result in timing violations or reduced lifetime of
the component.
3.2.1 V
CC
Decoupling
V
CC
regulator solutions need to provide sufficient decoupling capacitance to satisfy the
processor voltage specifications. This includes bulk capacitance with low effective series
resistance (ESR) to keep the voltage rail within specifications during large swings in
load current. In addition, ceramic decoupling capacitors are required to filter high
frequency content generated by the front side bus and processor activity. Consult the
Intel(R) IMVP-6 Mobile Processor Voltage Regulation Specification and appropriate
platform design guidelines for further information.
3.2.2 V
CCP
Decoupling
Decoupling must be provided on the motherboard. Decoupling solutions must be sized
to meet the expected load. To ensure compliance with the specifications, 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 would consist of a combination of low ESR bulk
capacitors and high frequency ceramic capacitors.