CAT3606

CAT3606 6-Channel Low Noise Charge Pump White LED Driver Description The CAT3606 controls up to four LEDs for the main display and two LEDs for the sub-display in cellular phones. The device is capable of operating in either 1x (LDO) mode or 1.5x charge pump mode. All LED pin currents are regulated and tightly matched to achieve uniformity of brightness across the LCD backlight. An external resistor (RSET) sets the nominal output current. The device can deliver as much as 20 mA per channel during low voltage operation (3 V), and 30 mA per channel during nominal operation (3.3 V). A constant high-frequency switching scheme (1 MHz) provides low noise and allows the use of very small value ceramic capacitors. A “zero” quiescent current mode can be achieved via the chip enable pin EN. The Main and Sub LEDs each have their own dedicated ON/OFF control pins ENM, ENS. Dimming can be achieved using either a DC voltage to control the RSET pin current, or by applying a PWM signal on the ENM and ENS pins. The device is available in a 16−pad TQFN package with a max height of 0.8 mm. Features Drives up to 4 Main LEDs and 2 Sub LEDs Separate Control for Main and Sub LEDs Compatible with Supply Voltage of 3 V to 5.5 V Power Efficiency up to 90% Output Current up to 30 mA per LED High−frequency Operation at 1 MHz 2 Modes of Operation 1x and 1.5x White LED Detect Circuitry on All Channels Shutdown Current less than 1 mA Small Ceramic Capacitors Soft Start and Current Li...