US Patent 7548440 Power and information signal transfer using micro-transformers

A power converter provides power across an isolation barrier, such as through the use of coils. A coil driver has transistors connected in a positive feedback configuration and is coupled to a supply voltage in a controlled manner by measuring the output power and opening or closing a switch as needed between the power supply and the coil driver. An output circuit, such as a FET driver, can be used with or without isolation to provide power and a logic signal.