Design of highly efficient affordable power management circuits in high voltage 0 point 35 micro metre technology for automotive applications

Abstract

Efficient power conversion is an extremely important area of research in modern day electronics. Because of wide range of supply voltages in which the ICs operate, the power conversion or the power management IC (PMIC) needs to work from one voltage range and deliver power at different voltage range. An automotive camera module needs to withstand high input voltage range and deliver multiple output voltages and load currents at very high step-down ratio. An affordable, reliable and highly efficient automotive reverse camera system is found to have all the required challenges for a VLSI designer to make it a very interesting research problem for this thesis work. A combination of DC-DC (switching converters) and low-dropout (LDO) regulator, which is known as hybrid regulator, is found to give the best compromise in terms of system efficiency, output voltage ripple while keeping the overall component count to the minimum. This work focusses on a generic system efficiency improvement solution based on the adaptive dropout of the LDO has been proposed. Optimal circuit design architecture with adaptive LDO dropout has been implemented to handle single DC-DC and upto three LDOs with independent voltage and current requirements. AMS 0.35um high-voltage CMOS technology has been used to design the power management circuits. The design of the two PMICs have been successfully completed and fabricated. The packaged ICs have been tested for their functionality. The innovation has been successfully validated in the lab and the experimental results prove the improved efficiency with respect to the conventional hybrid regulator across the 95% of the load current range and IC junction temperature upto 150 degC. The novel contributions of the thesis work is very generic and can be applied to any hybrid voltage regulators with DC-DC and LDO combination newline