Towards Chip-Scale Power Management: A Circuits Perspective

Full integration of power management circuits has been a vision and a goal of the power electronics and integrated circuits communities for many years, if not decades. However, while exponential semiconductor scaling has had a profound impact on data processing, storage, and communications, the same has not been true for circuits that process and delivery energy. On one hand, this is because power delivery circuits are constrained by the size and efficiency of passive components – inductors and capacitors – and thus by Maxwell’s equations and fundamental material properties. Yet, a host of applications, spanning portable computing, IOT, automotive, and renewable energy demand small, lighter, cheaper, and more efficient solutions.

This talk will address some of the current trends relating to advances in active and passive components, as well as new circuit architectures and design paradigms that are positioned to open the pathway to mm-scale in monolithically-integrated power conversion. A particular focus will be on the switched capacitor approach – more specifically on switched capacitor circuits and architectures that can be operated in resonant modes or hybridized with a small inductive impedance. These circuits leverage the fundamental advantages of capacitors compared to inductors, such as much higher energy-density and better scalability. Yet, compared to a pure SC approach, the use of a small amount of magnetic energy storage can dramatically improve power-density, efficiency, and add capabilities for variable regulation.

The talk will present a generalized framework for comparison of arbitrary converter topologies based on a charge-multiplier approach. This will be used to highlight which topologies – some well-known, some yet to be explored – have good prospects for high-density integration. Several past integrated circuit prototypes will be highlighted that achieved records for efficiency and power density in bulk CMOS.