PMP2493.1, Buck Converter with Minimum Component Count to Drive LEDs (45V @ 6A)

PMP2493.1, Buck Converter with Minimum Component Count to Drive LEDs (45V @ 6A). TPS40200 controller can be used as a low-cost LED driver. With an input voltage rating of 4.5 to 52V, it can power LED strings with regulated current and up to a 45 V drop across the string. Current is sensed across a resistor between the cathode of the string and ground and is compared against a 696mV reference to provide regulated current. Because the driver is a buck and not a boost or flyback, an open string will not produce voltages above the input voltage and over-voltage protection is not needed. The driver can operate in either the continuous or discontinuous mode. for output voltages above 35V the discontinuous mode is needed due to duty cycle limitation above 35V. The circuit shown has a Pulse Width Modulator (PWM) input for dimming purposes. Targeted current can be set with jumpers