Design and Verification of Speed-Independent Multiphase Buck Controller

Power regulators and converters impose high requirements on the latency and resilience of their control circuitry. In this paper we design a speed-independent multiphase buck controller based on a novel lazy token ring architecture, that allows overlapping the charging cycles of multiple phases as well as simultaneous activation of all phases to handle the sudden power demand. The advantages over traditional synchronous designs include reliable handling of asynchronous inputs from sensors, low-latency reaction to the changes in power demand (under-voltage, over-current, zero-crossing and high-load conditions), and more balanced utilisation of charging phases. The essential correctness properties of the developed controller have been formally verified, and the whole buck has been validated in the industrial settings using exhaustive simulation.