1. Feedback Loop Analysis and Optimized Compensation Slope of the Current-Mode Buck DC-DC Converter in DCM.
- Author
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Sugimoto, Yasuhiro, Sai, Toru, Watanabe, Kei, and Abe, Mikio
- Subjects
- *
DC-to-DC converters , *DIRECT currents , *CURRENT-mode circuits , *SWITCHING circuits , *BANDWIDTHS , *ELECTRIC potential - Abstract
Frequency characteristics of the total feedback loop of a current-mode buck DC-DC converter in the discontinuous conduction mode (DCM) are examined by formulating an equivalent small-signal transfer function using a proposed block structure that does not suffer direct influence from the current feedback. Utilizing this transfer function, it is clarified that the type of the compensation slope in a current feedback loop affects the loop frequency characteristics in DCM, and in terms of stability, high voltage gain and large 0-dB frequency bandwidth, the quadratic compensation slope is more effective than the linear compensation slope. The validity of the proposed block structure and formulations and the effectiveness of applying a quadratic compensation slope instead of a linear compensation slope in DCM are verified by comparing calculation results, SPICE simulation results and evaluation results using circuit and measurement data from an MOS current-mode buck DC-DC converter IC that had been previously fabricated. More than 10-dB higher voltage gain, three times larger 0-dB frequency bandwidth, more than 10-degree larger phase margin and faster recovery time in load current change are realizable in DCM compared with the case using a linear compensation slope. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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