ISBN 978-3-8439-5779-3

978-3-8439-5779-3, Reihe Elektrotechnik

Michael Hanhart
A Contribution to the Integration of DC/DC Switching Converters

314 Seiten, Dissertation Rheinisch-Westfälische Technische Hochschule Aachen (2025), Hardcover, A5

Zusammenfassung / Abstract

This work summarizes a novel concept for a 4-channel multi-color output LED driver for tunable white luminaires in conjunction with the achievements made in the field of DC/DC converters for photovoltaic (PV) applications. The LED driver ASIC is as a follow-up project of a previously developed low-effort topology, aiming to significantly improve performance, ease the silicon integration, and enable usage in a real application example. The biggest drawbacks of the existing solution must be addressed: the need for special LDMOS transistors, an additional low-impedance, current-sinking power supply, and poor color-mixing performance under low-light conditions. The second part of the thesis describes the design process of a maximum-power-point (MPP) tracking boost converter for submodule PV applications. Traditionally, PV panels have been connected in series, making the resulting string arrangement susceptible to partial shading. Thus, bypass diodes are used to short shaded substrings/modules. To overcome losses caused by fixed string currents, microinverters have been used for each PV-panel instead of a central string inverter. While they offer individual MPP tracking, they suffer from a large solution size with bulky components and a complex circuitry for DC/AC conversion. Based on these requirements, a DC/DC converter will be designed to tackle the challenges of micro-granular MPP tracking and complexity. Both ASICs were designed in 0.18 μm HV BCD processes with Cadence Virtuoso. Analog and mixed signal simulations were used to verify the electrical performance parameters before tapeout. The silicon has been validated by extensive measurements in the laboratory as well as in a PV panel in the field.