Abstract: Disclosed is a phase-controller and method of hysteretic control of a phase of a decoupled multiphase resonant converter, using a hysteretic window offset control parameter, the method comprising: determining a minimum 50% duty cycle (50% DC) operating frequency, fmin, from a set consisting of the respective 50% DC operating frequency of each phase of the multiphase resonant converter; in response to the 50% duty cycle operating frequency of the phase being different from fmin, adjusting the hysteretic window offset of the phase to change a current operating frequency of the phase towards fmin; and, in response to a change of an operating condition of the phase: re-adjusting the hysteretic window offset of the phase to change the operating frequency of the phase towards fmn; and in the event that a new 50% dc operating frequency of the phase, f*min, is less than fmin; replacing fmin by f*min, and communicating f*min as a new minimum 50% dc operating frequency to each other phase.

Abstract: Disclosed is a multi-phase coupled-LLC, CLLC, resonant converter, and controller therefor, the converter having a plurality of primary-side LLC circuits, each comprising a series-arrangement of a capacitance and two inductances between a respective input and a common node, wherein each input is switchable between a first supply voltage level and a second supply voltage level, the controller comprising: a hysteretic controller; and a finite state machine; wherein the hysteretic controller is configured to trigger a change of state of the FSM in response to a voltage level of a resonant capacitor of a one of the LLC circuits crossing a trigger voltage level; and wherein the FSM is configured to change between a plurality of states, wherein each state corresponds to a different combination of states for each of the LLC circuits of the multiphase CLLC. Corresponding methods are also disclosed.

Abstract: One example discloses a degradation circuit, including: a first set of structures configured to be coupled to a semiconductor package; a second set of structures, coupled to the first set of structures, and configured to be coupled to the package; wherein together the first and second set of structures form a Wheatstone bridge within a degradation detection element; and a controller, coupled to the degradation detection element, and configured to set an operational state of an integrated circuit (IC) within the package based on the degradation detection element.