A maximum power-point tracker without digital signal processing in 0.35μm CMOS for automotive applications

In the upcoming field of e-mobility roof-integrated photovoltaic systems are used to extend the cruising range of electric vehicles. Due to the roof's curvature the solar cells (SC) show different inclination angles to the sunlight, resulting in different maximum power points (MPP) and a lower harvested energy if all SCs are controlled by a centralized MPP-regulated DC/DC converter. A further issue is partial shading. The use of smart modules where a smaller SC number is tied to a module-integrated converter with MPP tracking (MPPT) improves the system efficiency. Current smart module controllers like the SPV1020 [5] use ADCs for voltage and current measurements together with digital processing. Quasi-analog MPPT methods for system-on-chip implementation in this field of application are discussed and tested [1,2] but not realized as ICs. In the field of energy harvesting for micro power applications converters with integrated analogue MPPT are already implemented [3] but the quality of the MPP regulation is too poor for the use in smart modules.