Demonstration circuit 749 is a multi-display LED controller featuring the LTC3206. The LTC3206 is a highly integrated multi-display LED controller. This device contains a high efficiency, low noise fractional step-up/step-down charge pump to provide power for a main and sub white LED display, plus an RGB color LED display. The LTC3206 requires only four small ceramic capacitors plus two resistors to form a complete 3-panel LED power supply and a current controller. Maximum currents for the main/sub and RGB displays are set independently with a single resistor. Current for each LED is controlled with an internal current source. Dimming control for all displays is achieved via a 2-wire I2C interface. The RGB or Sub panel may be disabled with the ENRGB/S pin. Sixteen dimming states exist for the main panel, sub panel, and the red, green, and blue LEDs resulting in up to 4096 color combinations. The LTC3206 charge pump optimizes efficiency based on VIN and LED forward voltage conditions. The part powers-up in step-down mode and automatically switches to step-up mode once the first LED current source begins to enter dropout. The charge pump can also be programmed to be in step-up mode using the I2C interface. Internal circuitry prevents inrush current and excess input noise during start-up and mode switching.