LED Driver, Charge Pump, 6-Channel

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 (1MHz) 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