Flyback topologies provide the simplest and lowest cost
solutions all isolated power conversion architectures. It’s no
wonder that they are the most commonly used topology for
AC/DC power supplies up to 100 W. Because of their low
resistance and minimal number of turns in helical windings,
planar magnetics are the high-frequency application
converter of choice for engineers. Planar transformers also
offer a slimmer mechanical profile that makes them useful in
Planar topologies also present a number of technical
challenges, such as their high inductance values and the
level of isolation the design requires for safety. A solution
to these challenges is the availability of customized planar
flyback transformers. Working with a knowledgeable
component supplier gives designers the ability to offer peak
power supply efficiencies of over 90 percent.
Designing More Efficient HV
Power Supplies Using Planar
Power supply efficiencies exceeding 90 percent
achievable through proper transformer design
By Cathal Sheehan, Technical Market Manager, Bourns, Inc.
Driven by efforts to lower energy costs and to satisfy green environmental initiatives, engineers are seeking to
improve industrial power supply electrical
efficiencies. Energy cost reductions can be
achieved with even small efficiency increases.
These benefits commonly contribute to more
productive, reliable and extended lifecycle
applications. However, as designs become
more complex and highly integrated, power
efficiency enhancements are more difficult to
Figure 1: The PCB-based transformer design
splits the primary winding enclosing the
secondary made from triple insulated wire.
The triple insulated wire on the secondary side
provides the reinforced insulation between
primary and secondary windings.