Inverter internal communication features are disclosed. A multiple-stage inverter includes DC to DC and DC to AC converter switches in different power domains, which share no common return path connection. Operating parameters for converter switches in both power domains are determined by a single controller, located in one of the power domains. Converter control signals are communicated from the controller across an interface between the power domains. Respective, separate controllers in each power domain are not required. Components on each side of the interface could be integrated into respective integrated circuits. A planar transformer implemented in wiring levels of a Printed Circuit Board (PCB) that carries components of the inverter could be provided to enable communications between the power domains while reducing component count and physical space requirements.