A Four-Phase Hybrid Step-UpDown Converter With RMS Inductor Current Reduction and Delay-Based Zero-Current Detection

Abstract

In this letter, a four-phase hybrid step-upx002F;step-down dcx2013;dc converter with a delay-based zero-current detector (ZCD) is proposed. The proposed power stage operates in step-up or step-down mode depending on the target output voltage. It utilizes hybrid switched-inductor-capacitor and dual-path topologies with multiphase operation to reduce conduction loss due to the dc resistance of the inductor by reducing the rms inductor current (<italic>I<sub>L</sub></italic>). The delay-based ZCD determines the zero-current point of <italic>I<sub>L</sub></italic> with a five-bit binary signal to compensate for the propagation delay between the control and the output signals of the driver. The system is fabricated using 180-nm CMOS technology. The power density is 1.838x00A0;Ax002F;mm(2), and the peak efficiency is measured at 89.49x0025; and 86.83x0025; in the step-down and step-up mode, respectively, with a load current range of up to 2x00A0;A.