by josh perry, editor
a recent article from eletimes.com explored the thermal concerns that engineers face in designing systems with point-of-load (pol) converters, particularly systems with tight space constraints where heat will be transferred to nearby components.
thermal management is an important consideration for designers of pol converters. (wikimedia commons)
“how hot does the package become due to its construction, layout, and thermal impedance?” the article asked. “thermal impedance of the package not only raises the temperature of the pol regulator, it also increases the temperature of the pcb and surrounding components, contributing to the complexity, size, and cost of the system’s heat removal arrangements.”
the two most common solutions have been using heat-conductive copper vias and layers of the pcb to remove heat or to increase the airflow across the system to dissipate heat (typically with heat sinks added to the components).
the article explained that choosing the right pol converter can give designers a competitive advantage before employing standard thermal management techniques.
“a pol regulator must meet the requirements of its application,” the article continued. “in choosing a pol regulator, one must assure its ability to do the job on the pcb, where the treatment of heat can make or break the application.”
the article suggested that engineers ignore power density statistics, examine the converter’s thermal derating curves, and look at its efficiency (combined with other thermal data).
“the pcb is responsible for absorbing and routing much of the heat from surface-mountable pol regulators,” the article added. “with the prevalence of forced airflow in today’s dense and complex systems, a cleverly designed pol regulator should also tap this free cooling opportunity to remove heat from the heat generating components such as mosfets and inductors.”
another suggestion is to “go vertical” and use a stacked inductor on top of the converter as a heat sink in a package that will draw the heat from the component into the top of the package and into the ambient. using 3-d packaging, engineers can reduce the footprint in already compact systems.
read the full article at https://www.eletimes.com/choose-cool-runninghigh-power-scalable-pol-regulators-save-board-space#.