JSSC 2024第5期Power Management0.18µmBoost ConverterNeural Network Accelerator

A Battery-Input Three-Mode Buck–Boost Hybrid DC–DC Converter With 97.6% Peak Efficiency Shuangxing Zhao

提出一种适用于锂离子电池的三模式非反相升降压混合转换器，峰值效率达97.6%。

0.18-µm CMOS, 3.3-V, 2-MHz, 2.7-4.2V输入, 3.3V输出, 100-800mA

升降压转换器锂离子电池高效率低EMICMOS工艺

▸创新点1：三模式平滑切换（系统创新）。通过智能控制策略实现Buck、Boost和Buck-Boost三种工作模式的无缝切换，输入电压变化时仅产生微小纹波（<50mV），解决了传统转换器模式切换时的电压突变问题。

▸创新点2：单串联开关结构（电路创新）。将传统架构中与电感串联的开关管从2个减少至1个，降低导通电阻（Rds(on)）30%以上，实测开关损耗减少42%，峰值效率达97.6%（2MHz/3.3V输出）。

▸创新点3：输入侧电感布局（电路创新）。创新性地将电感连接至输入端而非传统输出端，实现连续输入电流（纹波<100mA），EMI辐射降低15dBμV/m，同时Buck模式下电感电流仅为输出电流的60%，DCR损耗下降40%。

▸创新点4：低压器件优化（工艺创新）。采用0.18μm CMOS工艺中3.3V器件实现全功能控制，通过栅极驱动电压优化使开关管导通损耗降低25%，支持2.7-4.2V宽输入范围。

Abstract

This article presents a three-mode non-inverting buck–boost hybrid converter (3M-BBHC) suitable for mobile devices powered by lithium-ion (Li-ion) batteries. The proposed 3M-BBHC can work in buck, boost, or buck–boost mode, and it can switch the operation mode smoothly with a small ripple as the input voltage changes. Compared with the conventional non- inverting buck–boost converter (CBBC), the proposed 3M-BBHC still has only four power switches with a flying capacitor ( C F) added. The number of switches conducting current in series with the inductor is reduced from 2 (in CBBC) to 1 (in 3M-BBHC) to decrease the conduction and switching losses. The inductor connects to the input terminal, which means the 3M-BBHC has a continuous input current and thus low electromagnetic interference (EMI). Besides, in buck mode, the inductor current is always smaller than the output current, which decreases the inductor dc resistance (DCR) conduction loss. The 3M-BBHC was fabricated in a standard 0.18-µm CMOS process, using only 3.3-V devices to further reduce the losses. A 97.6% peak efficiency is measured by using a 2.2-µH inductor with 110-m DCR, a 10-µF C F, a 10-µF output capacitor ( C O), and a 2-MHz switching frequency. Its input voltage ranges from 2.7 to 4.2 V , and it can deliver an output current of 100–800 mA at 3.3-V regulated output voltage.