Transient frequency modulation: A new approach to beat-frequency current sharing issues in multiphase switching regulators

Under high-frequency load transient conditions, conventional multiphase voltage regulators (VRs) suffer from large beat-frequency oscillations of the phase currents. This phenomenon can result in extra electrical and thermal stress on power components, so compromising system reliability. In this paper, a novel multiphase switching regulator topology is proposed, which is composed of a conventional multiphase PWM modulator, a frequency modulator and a load transient detector. The proposed topology, when compared to the conventional multi-phase PWM modulators during repetitive load transients, significantly reduces current oscillations, guaranteeing system reliability and current balancing for any load frequency higher or lower than switching frequency.