A Li-ion-Battery-Input 1-to-6V-Output Bootstrap-Free Hybrid Buck-or-Boost Converter Without RHP Zero Achieving 97.3% Peak Efficiency 6μs Recovery Time and 1.13μs/V DVS Rate

In today’s mobile devices, buck-boost converters are widely used to convert the Li-ion battery voltage $\left(\mathrm{V}_{1 \mathrm{~N}}\right)$, typically ranging from 2.7 to 4.2 V, to the specific output voltage $\left(V_{0}\right)$ levels required by various modules. While certain modules only need a fixed supply voltage [1–5], others, such as envelope tracking RF power amplifiers (PA), demand a wide range of supply voltages and exhibit fast changes in currents and voltages [6]. At times, the supply voltage of the PA is required to switch from sub-1 V to 6V in a short time. Therefore, the buck-boost converter must handle the wide output voltage ranges and provide fast dynamic voltage scaling (DVS). Recent works in [1–5] only support a fixed $V_{0}$ instead of a wide range. In addition, conventional buck-boost converters and the hybrid converters in [1–3] suffer from the right-half-plane (RHP) zero, resulting in slow dynamic response. The dual-channel 3-level converter in [6] can eliminate the RHP zero and achieve a fast DVS rate. However, its ideal conversion ratio (CR) in the boost mode is limited below 2. In particular, when the battery voltage is close to 2.7V, it fails to provide 6V or even higher. Meanwhile, 10 switches in total are required, increasing the complexity. To address the mentioned issues, this paper proposes a hybrid RHP-zero-free buck-or-boost (BoB) converter which can eliminate the RHP-zero in both buck and boost modes and achieve a theoretically unlimited CR. At the same time, a continuous output delivery current $\left(\mathrm{I}_{\mathrm{D}}\right)$ can be provided to reduce the output voltage ripple $\left(\Delta V_{0}\right)$.