Dear Dennis... EN-Genius Network's Dennis Feucht answers your design queries in his new Circuit Design Clinic! October 2007

EN-Genius Network presents a new, interactive analog design service to readers! Send us your design questions (with relevant data; schematics in JPEG or GIF, please) for some free engineering advice from EN-Genius Network's circuit consultant, Dennis Feucht, on how you might solve a design problem or improve circuit performance. Submissions may be edited for clarity or brevity, and submitters and their email addresses will remain anonymous (unless otherwise indicated). Please send your questions to Dennis here.

MOSFET Voltage Optimization

Q: Is there an optimum MOSFET voltage for power electronics applications that will minimize power loss?

A: This question falls in the general category of impedance matching in that an optimal voltage-current tradeoff point, or impedance, is sought. This arises not only in the more common circuit applications where the maximum-power-transfer theorem is applied (such as calculation of a transformer turns ratio), but also in less obvious applications such as the driver output impedance driving a motor to match the mechanical impedance as referred to the electrical side of the machine.

Read the entire response here (86 KB PDF)