A 94.4% Peak Efficiency Coupled-Inductor Hybrid Step-Up Converter With Load-Independent Output Voltage Ripple

This article introduces a coupled-inductor hybrid step-up converter (CIHSUC) designed for low-ripple power supply applications in battery-operated devices. The CIHSUC combines the advantages of both a boost converter and a KY converter by proposing a novel hybrid converter topology that connects the input and output terminals of the converter in series with the coupled-inductor, resulting in a high conversion ratio (CR) and load-independent ultra-low output voltage ripple. By utilizing a coupled inductor instead of two discrete inductors, the CIHSUC further reduces inductor current ripple, output voltage ripple, and system size. Furthermore, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V^{2}I_{\text {C}}$ </tex-math></inline-formula> adaptive <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small>-time (AOT) control method is proposed to enhance the transient response and loop stability. Fabricated in a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.18~\mu $ </tex-math></inline-formula>m BCD process, the converter achieves a peak efficiency of 94.4% at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V_{\text {IN}}} =5$ </tex-math></inline-formula> V, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V_{\text {O}}} =12$ </tex-math></inline-formula> V and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I_{\text {Load}}} =300$ </tex-math></inline-formula> mA. Additionally, the measured output voltage ripple remains below 20 mV within the input range of 2–5 V and the output range of 5–15 V, representing up to a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.6\times $ </tex-math></inline-formula> reduction compared to the theoretical optimum of a conventional boost converter.