Introduction
Similar to the SEPIC DC/DC converter topology, the ZETA
converter topology provides a positive output voltage from
an input voltage that varies above and below the output
voltage. The ZETA converter also needs two inductors
and a series capacitor, sometimes called a flying capacitor.
Unlike the SEPIC converter, which is configured with a
standard boost converter, the ZETA converter is configured
from a buck controller that drives a high-side PMOS
FET. The ZETA converter is another option for regulating
an unregulated input-power supply, like a low-cost wall
wart. To minimize board space, a coupled inductor can be
used. This article explains how to design a ZETA converter
running in continuous-conduction mode (CCM) with a