Platform Power Requirements
R
98
Intel
®
855PM Chipset Platform Design Guide
resistor network. See Figure 49. V
REF
is used to set the highest output voltage in conjunction with the
selection of R5 & R6 in the resistor network.
Figure 49. V
CCP
Block Diagram
Voltage
Regulator
R6 *
R5 *
V
REF
Intel Pentium
M processor
VCCP
Intel 855PM
MCH
* +/-0.1%
Tolerance
Recommended
Intel 82801DBM
ICH4M
ITPFLEX
5.5. V
CC-MCH
Output Requirements
The V
CC-MCH
output rail provides power to the core of the Intel 855PM MCH. The nominal voltage of
V
CC-MCH
is 1.2 V. The voltage regulator can be programmed via an external resistor network. See Figure
50. V
REF
is used to set the highest output voltage in conjunction with the selection of R7 and R8 in the
resistor network..
Figure 50. V
CC-MCH
Block Diagram
Voltage
Regulator
R7 *
R8 *
V
REF
Intel
855PM
MCH
VCC_MCH
* +/-0.1%
Tolerance
Recommended
5.6. Thermal
Power
Dissipation
Power dissipation has traditionally been a thermal/mechanical challenge for mobile system designers.
The amount of current required from the processor power delivery circuit and the heat generated by
processors has increased as processor frequencies go up and the silicon process geometry shrinks. The
package of any integrated device can only dissipate so much heat into the surrounding environment. The
