Survey on Integrated High-Power Low-EmissionOutput Stages for Drivers of Low-FrequencyResonant Loads

To drive low-frequency resonant loads with highoutput power and low emission, Class-AB push-pull stagesare state of the art. But their theoretically superior emissionperformance is often sacrificed for efficiency. A differential Class-D concept is a promising alternative, because it can combineboth excellent power efficiency and low emissions. This work isa survey on the main sources of distortions for both amplifiertopologies with basic considerations to internal power losses andefficiency. The investigations are based on simple circuits andcompared to measurement results of two integrated circuits.