A Dual-Phase Dual-Path Hybrid Buck-Boost Converter with Offset-Controlled Zero-Current Detection Achieving 95.88% Peak Efficiency

초록

This paper presents a dual-phase dual-path hybrid buck-boost (DPBB) converter with an offset-controlled zero-current detector for Li-ion battery applications. Compared with inductive buck-boost converters, the proposed hybrid converter has a continuous input current, reducing the input voltage (VIN) ripple, which is caused by the parasitic inductance of the bonding wire. The proposed switching operation of the DPBB topology shows a low inductor current ripple with the continuous output delivery current; therefore, the ripple of the output voltage (VOUT) is reduced with the efficiency improvement. Compared with the prior hybrid buck-boost converters, it supports the buck and boost modes only by adjusting the duty cycle, so this addresses the issues of mode transitions. The proposed work utilizes the dual-phase operation to lower the conduction loss and improve the dynamic range. The proposed offset-controlled zero-current detector compensates for the timing error owing to the propagation delay of the control signals to reduce the reverse current from the output. The chip is fabricated using a 180-nm BCD process. It regulates VOUT at 3.3 V with a wide VIN range of 2.8 V to 4.2 V. Peak efficiencies of 95.88% and 93.08% are achieved in the buck and boost modes, respectively, with 140 m Omega of inductor DC resistance.

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