Abstract: Some of the key challenges in solar Photovoltaic (PV) power system are temperature variation, semiconductor characteristics of individual modules and irradiation variation. In practice, individual solar modules normally operate at different temperatures and electronic characteristics, therefore resulting in the modules experiencing individual thermal and irradiation conditions that adversely affect the output power to the load. This paper presents a microprocessor-based modular DC-DC converter that regulates the bus voltage which in turn tracks the maximum power point of the array.