CAT3604A

CAT3604A 4-Channel Regulated Charge Pump White LED Driver Description The CAT3604A is a charge pump operating in either 1x (LDO) mode or 1.5x fractional mode regulating current through each of the 4 LED pins. Operation at a fixed high frequency of 1 MHz typical allows the use of very small value ceramic capacitors. The CAT3604A drives white light-emitting diodes (LEDs) connected in parallel and provides tightly matched regulated current to achieve uniformity of brightness in LCD backlighting applications. An external resistor RSET controls the output current level. LED currents of up to 30 mA are supported over a range of input supply voltages from 3 V to 5.5 V, making the device ideal for battery-powered applications. LED dimming can be accomplished by several methods including using a DC voltage to set the RSET pin current, applying a PWM signal on the Control signals, or adding a switched resistor in parallel with RSET. The Enable input pin allows the device to be placed in power-d...