CAT3604

The CAT3604 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 1MHz typical allows the use of very small value ceramic capacitors.

The CAT3604 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 evel. LED currents of up to 30mA are supported over a range of input supply voltages from 3V to 5.5V, making the device ideal for battery-powered
applications.

CAT3604 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 CAT3604 features short circuit and overcurrent limiting protection. The device is available in a 16-lead thin QFN package with a max height of 0.8mm.