Time-Multiplexing Current Balance Interleaved Current-Mode Boost DC-DC Converter for Alleviating the Effects of Right-half-plane Zero

Abstract

In the present study, a time-multiplexing current balance (TMCB) current-mode boost converter is proposed to improve the transient performance. Generally, the crossover frequency of a conventional boost converter is limited to half or less than the right-half-plane (RHP) zero to ensure the system stability. The transient performance of a conventional boost converter is degraded due to its limited bandwidth. The proposed TMCB boost converter extends its bandwidth and moves the RHP zero to a higher frequency to improve the transient performance using two inductors in one channel. Besides, the small signal model of dual phase system which considers cross-couple effect and offset correction is presented. The proposed converter requires an extra inductor and a slight increase in the size of the printed circuit board layout and die size. Using time multiplexing, two inductors were operated in an interleaved phase at a switching frequency of 5 MHz rather than a single inductor system operated at a switching of 10 MHz for the same ripple required. Experimental results show that the TMCB technique is effective in correcting the mismatch in the current of the inductors even if the difference between the inductors is large. Furthermore, the proposed converter can improve the settling time from 52 to 22 mu s due to an extended bandwidth.