AMD-K6-2E Datasheet, PDF (313/332 Pages) Advanced Micro Devices – AMD-K6™-2E Embedded Processor

22529B/0—January 2000
Preliminary Information
AMD-K6™-2E Processor Data Sheet
16.4
Layout and Airflow Considerations
Voltage Regulator
A voltage regulator is required to support the lower voltage
(3.3 V and lower) to the processor. In most applications, the
voltage regulator is designed with power transistors. As a
result, additional heatsinks are required to dissipate the heat
from the power transistors. Figure 109 shows the voltage
regulator placed parallel to the processor with the airflow
aligned with the devices. With this alignment, the heat
generated by the voltage regulator has minimal effect on the
processor.
Voltage Regulator
Processor
Airflow
Figure 109. Voltage Regulator Placement
A heatsink and fan combination can deliver much better
thermal performance than a heatsink alone. More importantly,
with a fan/sink, the airflow requirements in a system design are
not as critical. A unidirectional heatsink with a fan moves air
from the top of the heatsink to the side. In this case, the best
location for the voltage regulator is on the side of the processor
in the path of the airflow exiting the fan sink (see Figure 110 on
page 296). This location guarantees that the heatsinks on both
the processor and the regulator receive adequate air
circulation.
Chapter 16
Thermal Design
295