Synchronous Buck Converter Flicker Reduction

The patent introduces a current decay phase that periodically reduces current amplitude to zero or near-zero values during each switching cycle. This periodic action creates a dual-phase operation: a main phase with higher current for efficient power transfer, and a decay phase with reduced current to eliminate flickering. The decay phase is timed to occur before the light source can respond visually to current variations, effectively suppressing flicker while maintaining overall system efficiency.

The patent dynamically adjusts the current waveform by introducing a controllable decay phase where the current amplitude is reduced to zero or near-zero. This dynamic modification allows the system to adapt the current profile within each switching cycle, creating a time-varying current amplitude that prevents sustained high current levels that cause flickering while maintaining efficient power conversion during the active phase.

The patent employs periodic current decay phases interspersed with high-current power transfer phases. During the decay phase, current is reduced to eliminate flickering, while during the subsequent active phase, current is restored to high levels for efficient power transfer. This periodic alternation ensures that energy efficiency is maintained over the complete cycle while flickering is suppressed during the decay portion.

The patent maintains continuous power transfer by seamlessly transitioning between the current decay phase and the active power transfer phase. The decay phase does not represent a complete interruption but rather a controlled reduction that prepares for the next efficient power transfer cycle. This continuous operation ensures that useful power transfer action is maintained throughout the switching cycle while periodically eliminating flickering conditions.