6V DC to DC Single Output Power Supply

Application has been designed to convert a USB input of 5V to a 6V output to use as a battery charger. The 5.0V USB input must limit the input current to less than 500mA even if the 6.0V output is loaded enough to bring the output lower than 6V to as low as 0V. The SP6126 Circuit accomplishes using a Buck-Boost regulator Circuit and an external input current limit Circuit using a rail-to-rail input Op-Amp to sense and control the input current