"Design and implementation of closed loop control for integrated isolated DC/DC converter''

Recently several semiconductor companies have released various products including fully integrated isolated DCDC converters. Output voltage regulation and reasonable light load efficiency are key requirements for these converters. Among existing solutions, output voltage regulation is achieved by means of a burst-mode regulation at primary side or by phase-shifting the secondary side power stage. The former technique usually requires a dedicated isolation channel implemented with isolation capacitors while the latter requires an additional transformer coil for clock reconstruction. On top of the output regulation, a status of the converter outputs is sometimes required on the input side which adds data backward signaling on top of the regulation loop information. Our prototype achieves close-loop regulation and backward data transmission using only the power isolation transformer thus providing a technology independent and cost effective solution. The concept leverages the resonant behavior of these isolated converters by detuning the secondary side power stage and detecting the change in resonance on the primary side.