Distributed Switching and Coupled Passives for High Performance Power Electronics

Combining (1) many distributed switches and (2) coupled passives decouples the switching and passive access frequencies, fundamentally improving power electronics performance. The equality of the switching and passive access frequencies in single-switch power converter cells (e.g. buck) limits the achievable bandwidth and efficiency. Using distributed switches (e.g. multiphase, multilevel) and coupled passives (e.g., coupled inductors, series stacked capacitors, and transformers) together allows the passives to see a higher frequency than the switches; this enables the use of low, efficient switching frequencies and small, fast, high-frequency passives. This paper overviews the principles of a family of scalable power architecture with distributed switching and coupled passives, including frequency multiplication, passive balancing, transient inductance reduction, and internal dynamic consolidation. This theory is applied to design a 64× interleaved coupled inductor Li-Fi transmitter achieving above-switching-frequency communication-over-power with PAPR=1.2 dB and SFDR=35 dB while driving 400 W LEDs with 94.0% efficiency.