Compact Galvanically Isolated Architectures for Low-Power DC-DC Converters with Data Transmission

Abstract

This paper reviews state-of-the-art architectures for galvanically isolated DC–DC converters with data transmission for low-power applications. Such applications do not have stringent requirements, in terms of power efficiency, but ask for very compact, highly integrated implementations. To this aim, architecture simplicity is crucial, especially when data transmission and/or output power regulation are required. Since the bottleneck of galvanically isolated systems is the isolation device (i.e., typically a stacked thick oxide or polyimide transformer), the reduction of the number of isolated links, while preserving both power and data functionalities, is the more effective strategy to increase the level of integration, reduce the form factor, and have a lower cost per channel. Specifically, this review compares the pros and cons of different architectures that address this challenge differently from traditional solutions.

Fully Integrated Galvanic Isolation Interface in GaN Technology

“…6. Proper aspect ratio (i.e., ratio of the longer to shorter side), metal width, and turn ratio between antennas were set to achieve a good trade-off between contrasting requirements such as the coupling factor (k), the quality factor (Q), the self-resonant frequency (SRF), and the chip size [36], [37].…”

“…This requirement, along with the introduction of a reinforced galvanic isolation standard at 10 kV, can well be faced with the package-scale isolation approach [32], [33]. Indeed, this approach can be exploited using RF-coupled planar microantennas to implement a highly isolated data communication interface [34], [35], [36], [37]. These works show interesting performance, but they are all in CMOS/BCD technologies while no GaN fully integrated implementations are available.…”