DC1265A-B: 360mA @ 5.1V Max, 2.9 ~ 5.5V in

Demonstration circuit DC1265A-B is a 360mA Universal 18-Channel LED Driver with twelve white LEDs and two RGB LEDs featuring the LTC3220-1.

The LTC3220-1 is a low noise charge pump designed to drive 18 universal LED (ULED) current sources. The LTC3220-1 requires only five small ceramic capacitors to form a complete LED power supply and current controller.

The maximum display currents are set with an internal precision current reference. On/Off blinking, gradation, intensity, and a software controlled shutdown are accomplished via an I2C serial interface. See the LTC3220-1 data sheet for more information on this process. There are 64 dimming states available for the universal LEDs.

The charge pump optimizes efficiency based on the voltage across the LED current sources. The part powers up in 1x mode and will automatically switch to boost mode whenever any enabled LED current source begins to drop out. The first dropout switches the part to 1.5x mode and a subsequent dropout switches the part into 2x mode. The part resets to 1x mode whenever a data byte is updated via the I2C port.