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.