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 R 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-down mode with ""zero"" quiescent current.The CAT3604A features short circuit and overcurrent limiting protection. The device is available in a 16-pad TQFN package with a max height of 0.8 mm.
