System Demystification III: Understanding Power Supply Operating Altitude
From the capital of Tibet, to the once-bustling mining town of Leadville, Colorado, our planet’s mountainous terrain has not stopped mankind from settling down in some pretty altitudinous places. Residents of the world’s highest cities have acclimated to the decrease in pO2 , but design engineers need to ensure that their electronic devices are up to the same challenge. The decrease in air pressure as altitude rises away from sea level has some interesting effects on the operation of electronic devices. These effects are particularly pronounced for power electronics circuits such as switch mode power supplies (SMPS) which dissipate considerable amounts of heat, and often contain high voltage networks. This month’s bulletin will provide an introduction to the physical phenomena that spawn power converter design challenges for high altitude applications.