Disclosed herein are various embodiments of coil transducers and galvanic isolators configured to provide high voltage isolation and high voltage breakdown performance characteristics in small packages. A coil transducer is provided across which data or power signals may be transmitted and received by primary and secondary coils disposed on opposing sides thereof without high voltage breakdowns occurring therebetween. At least portions of the coil transducer are formed of an electrically insulating, non-metallic, non-semiconductor, low dielectric loss material. The coil transducer may be formed in a small package using, by way of example, printed circuit board, CMOS-compatible and other fabrication and packaging processes.