A New Improved Ultra-Fast-Response Low-Transient-Voltage Buck Converter With Transient-Acceleration Loops and V-Cubic Techniques

Jiann-Jong Chen,Joshua Ku,Yuh-Shyan Hwang,Chien-Hung Lai,Wei-Ming Jiang

doi:10.1109/access.2022.3140279

Jiann-Jong Chen, Joshua Ku + Show 3 more

Open Access

https://doi.org/10.1109/access.2022.3140279

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Abstract

This paper presents a new improved ultra-fast-response low-transient-voltage buck converter with transient-acceleration loops and V-cubic techniques. Firstly, the proposed buck converter is based on optimum-damping control, so it is necessary to add a slope-compensation circuit to accelerate the transient response and decrease the transient voltage. Secondly, the proposed converter utilized the adaptive on-time controlled and V-cubic techniques to stabilize the switching frequency and promote the conversion efficiency. Thirdly, we utilized a rail-to-rail operational transconductance amplifier, which was used as a current-sensing circuit, to reach the feature of wide input range, so that it can directly sense the voltage without voltage dividing resistors. The rapid transient response and small transient voltage can be obtained when the load current changes. The proposed converter is fabricated with TSMC <inline-formula> <tex-math notation="LaTeX">$0.18~\mu \text{m}$ </tex-math></inline-formula> 1P6M process. The switching frequency is 3 MHz. The total area of the chip is 1.44 mm<sup>2</sup> (with PADs). The measured results are as follows. When the load current varies between 50 mA and 500 mA, the fastest recovery time is only <inline-formula> <tex-math notation="LaTeX">$1.6 ~\mu \text{s}$ </tex-math></inline-formula>, and the overshoot and undershoot are both 20 mV. The maximum efficiency is 90.1%.

Highlights

The major contributions of this paper are listed in the following: (1) We used a new current-sensing circuit without voltage dividers to design the proposed converter. It can be operated rail-to-rail and improves the dynamic response; (2) The new current-sensing circuit consisted no switches and it is without switching noise; (3) We have proposed a new architecture of fasttransient-response and low-transient-voltage buck converter with transient-acceleration loops and V-cubic techniques
EXPERIMENTAL RESULTS The proposed new improved ultra-fast-response lowtransient-voltage buck converter with transient-acceleration loops and V-cubic techniques is fabricated with TSMC 0.18μm CMOS 1P6M process
The proposed new improved ultra-fast-response lowtransient-voltage buck converter with transient-acceleration loops and V-cubic techniques is implemented with TSMC 0.18μm CMOS 1P6M process with a chip area of 1.44 mm2

Summary

INTRODUCTION

The major contributions of this paper are listed in the following: (1) We used a new current-sensing circuit without voltage dividers to design the proposed converter. It can be operated rail-to-rail and improves the dynamic response; (2) The new current-sensing circuit consisted no switches and it is without switching noise; (3) We have proposed a new architecture of fasttransient-response and low-transient-voltage buck converter with transient-acceleration loops and V-cubic techniques. The power stage includes the power transistors, output inductor and the capacitor, the controller is composed of a type-III compensator, a current-sensing circuit, a dynamic slope generator, an adaptive on-time controller, a non-overlapping circuit, and driver circuits.

COMPENSATOR

Rfb1 C 3

DYNAMIC SLOPE GENERATOR

EXPERIMENTAL RESULTS

CONCLUSION