An adaptive sampling method for a highly reliable digital control power converter

Synchronous sampling method is commonly applied to digital control power converter circuits in various applications. However, when the duty ratio of the converter is extremely high or low, this method may be affected by switching noise via current sensors or AD converters, resulting in inaccurate output of the power converter circuit. As a countermeasure, this paper proposes an adaptive sampling method for a digital control power converter circuit on an FPGA (Field Programmable Gate Array). To avoid overshoot and undershoot noises during the switching operations, sampling points of the AD converter will be tuned adaptively regarding the duty ratio of each switching cycle. This paper further illustrates simulation results and experimental results of the proposed method, where successful noise avoidances are verified. In consequence, the reliability of the power converter circuit is improved.