Class E resonant inverters can deliver any power with nearly 100% efficiency at high frequencies, achieving over 95% practical efficiency, particularly useful in portable lighting applications. They utilize zero voltage switching to exploit LCR resonance for AC power delivery, allowing for flexible load configurations. The design incorporates sub-optimal operation without significant efficiency loss, harnessing the characteristics of the switching device.

1. CLASS E RESONANT
INVERTERS AND RECTIFIERS

2. • Class E Resonant Inverters are theoretically
capable of delivering any power to a load and
achieve 100% efficiency at any frequency of
operation.
• In practice efficiency in the “high 90's” can be
achieved into megahertz frequencies regardless
of inverter output powers.
• The topology also allows the manipulation of
output power through sub-optimal operation, with
a negligible efficiency penalty.
• Class E topology for use in the growing market
for portable, battery powered lighting.
• It exhibits a peak recorded power efficiently of
over 98%, and a conservatively measured
efficiency of 95% across a range of dimming

3. • Class E Zero Voltage Switching (ZVS) Inverter
exploits LCR resonance to deliver AC power to a
load.
• A series resonant circuit is excited from a DC
source via a large inductance Lf through a switching
IGBT.
• Provided Lf is large enough, the input to the IGBT
and resonant circuit appears as a current source.
• The series resonant circuit generates voltage gain
of magnitude equal to its quality factor.
• A load may make up any part of the LCR circuit, as
do the parasitic characteristics inherent in the
switching device.
• The body diode of the IGBT is exploited to allow for
so-called sub-optimum mode operation
• for a load with a a variable resistance. Describes