Step Dimmable Quasi-Resonant Primary Side Current-Mode Controller for LED Lighting with thermal foldback

The NCL30083 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. The device is highly integrated with a minimum number of external components. A robust suite of safety protection is built in to simplify the design. The device supports 5 step log dimming down to 5%. To enhance system lifetime, it has current foldback at a user programmable temperature point. While the NCL30083 has integrated fixed overvoltage protection, the designer has the option to program a lower overvoltage protection level.