The NCL30081 is a PWM current mode controller targeting isolated flyback and non-isolated buck-boost constant current topologies. The controller operates in a quasi-resonant mode to provide high efficiency. Thanks to a novel control method, the device is able to precisely regulate a constant LED current from the primary side. This removes the need for secondary side feedback circuitry, biasing and an optocoupler. This controller has integrated 5 step log dimming which allows and LED bulb to be dimming from a standard wall switch.