A Transformer Class E Amplifier

Abstract

In a high-efficiency Class E ZVS resonant amplifier a matching and isolation transformer can replace some or even all inductive components of the amplifier thus simplifying the circuit and reducing its cost. In the paper a theoretical analysis, a design example and its experimental verification for a transformer Class E amplifier are presented. In the experimental amplifier with a transformer as the only inductive component in the circuit high efficiency ηMAX = 0.95 was achieved for supply voltage VI = 36 V, maximum output power POMAX = 100 W and the switching frequency f = 300 kHz. Measured parameters and waveforms showed a good agreement with theoretical predictions. Moreover, the relative bandwidth of the switching frequency was only 19% to obtain output power control from 4.8 W to POMAX with efficiency not less than 0.9 in the regulation range.

Single-Switch High-Frequency DC–DC Converter Using Parasitic Components

“…Another major benefit of this converter is that the resonant network absorbs the parasitic components such as leakage inductances of the transformer and the junction capacitance of the switch. Parasitic absorption has actually been widely used in many topologies [17], [26]. Especially in [26], not only leakage inductances are absorbed to the resonant network but also they entirely replace some inductive components, which simplifies the circuit and lowers the cost.…”

“…Parasitic absorption has actually been widely used in many topologies [17], [26]. Especially in [26], not only leakage inductances are absorbed to the resonant network but also they entirely replace some inductive components, which simplifies the circuit and lowers the cost. The proposed design scheme also includes the condition to replace several resonant elements by the parasitic components.…”