A Single-Link Multi-Domain-Output (SLiMDO) Isolated DC-DC Converter with Passive Magnetic Flux Sharing for Local Energy Distribution and Rx Behavior Sensing-Based Global Power Modulation

Galvanically isolated DC-DC converters are gaining more attention in industry for industrial automation and electrical vehicles (e.g., motor drives, battery management systems), consumer electronics (e.g., power adapters, gate drivers for hybrid converters), grid-tied devices, and medical applications. They are used to provide protection between domains while being able to transmit power through the isolation barrier. With the increase of system complexity, multiple outputs with each operating at a dedicated domain are widely used, e.g. for high-/low-side/floating gate drivers for converters or motor drivers, and sensor/control/communication circuits at different modules/packs for battery management systems, etc. Only [1] can provide two outputs with a single micro-transformer, however, its outputs are at the same domain. For miniaturization, recent research has led to developing in-package solutions with micro-transformers [1]–[10]. The transformer designs in [2]–[6] require special process, increasing the cost, while the power efficiency is limited due to the relatively low quality and inductance, thus leading to higher conduction and switching losses (>100MHz for [3], [8]). In terms of closed-loop control, early designs [2]–[5] typically utilized Pulse Width Modulation (PWM) or Pulse Frequency Modulation (PFM) for power regulation. However, additional digital isolators are required to transmit control signals between the transmitter (Tx) and the receiver (Rx). The work in [1] introduced discrete frequency modulation (DFM) with Rx output rotation for Tx power control and Rx voltage regulation. However, the rotation relied on communications between the two Rx outputs within the same domain, and digital isolators were also required between Tx and Rx.