One LED White LED Driver for Lighting

Circuit has been designed to provide 3 to 5Vin boost to White LEDs at approximately 4V output at 1.5Amps.High efficiency and 3-5Volt input dictated the choice of the controller and external components. In order to reduce the reference voltage to a low 150mV and improve efficiency, an additional IC Op-Amp (LMV321) was used to amplify the reference to 1.2V feedback voltage. The SP6121 is the synchronous buck controller that is being used as a buck/boost DC/DC controller