Description
The NCL30100 is a compact switching regulator controller intended for space constrained constant current high−brightness LED driver applications where efficiency and small size are important. The controller is based on a peak current, quasi fixed−off time control architecture optimized for continuous conduction mode step−down (buck) operation. This allows the output filter capacitor to be eliminated. In this configuration, a reverse buck topology is used to control a cost effective N−type MOSFET. Moreover, this controller employs negative current sensing thus minimizing power dissipation in the current sense resistor. The off time is user adjustable through the selection of a small external capacitor, thus allowing the design to be optimized for a given switching frequency range. The control loop isdesigned to operate up to 700 kHz allowing the designer the flexibility to use a very small inductor for space constrained applications.The device has been optimized to provide a flexible inductive step−down converter to drive one or more high power LED(s). The controller can also be used to implement non−isolated buck−boost driver topologies.