Single-ended primary-inductor converter (SEPIC)

The single-ended primary-inductor converter (SEPIC) is a DC/DC converter topology that allows the electrical potential (voltage) at its output to be greater than, less than, or equal to that at its input. The output of the SEPIC is controlled by the duty cycle of the control switch. Essentially similar to a traditional buck-boost converter, but with three primary advantages. It has a non-inverted output (the output has the same voltage polarity as the input), uses a series capacitor to couple energy from the input to the output (and thus can respond more gracefully to a short-circuit output), and is capable of true shutdown.

Block diagram

Design challenges

  • Economical, single MOSFET design – low QG(tot) and low FOM for best efficiency

MOSFET and GaN FET Handbook

Drawing on over 20 years’ of experience, the MOSFET and GaN FET Application Handbook: A Power Design Engineer’s Guide brings together a comprehensive set of learning and reference materials relating to the use of MOSFETs and GaN FETs in real world systems.

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