DC1187A

DC1187A demonstration circuit is a RGB LED driver and charge pump featuring the LTC3212. The LTC3212 is a low noise boost charge pump capable of driving three LEDs at up to 25mA each. This device requires only one flying capacitor, two by-pass capacitors, and one to three programming resistors. Each LED may be turned on individually, in combination with each other, or in white mode using a single wire interface. White mode optimizes the red, green, and blue current settings to provide the best white color. LED currents are regulated using internal low dropout current sources. Automatic mode switching optimizes efficiency by switching modes only when a dropout is detected.

• Input supply voltage range from 2.7 to 5.5V
• 8µA max IVIN shutdown current at LEDEN = LOW
• 0.4mA typ IVIN operating current at ICPO = 0mA, 1X mode
• 5.24mA typ ILED at RISET = 33.87kohm (Not in White Mode)
• 5.24mA typ ILEDG(WHITE MODE) at RISET = 33.87kohm
• 3.93mA typ ILEDB (WHITE MODE) at RISETG = 33.87kohm
• 4.72mA typ ILEDR (WHITE MODE) at RISETG = 33.87kohm
• 150mA typ ILED dropout voltage (VILED) at mode switching threshold, ILED = 15mA
• 5.1V typ charge pump output clamp voltage
• 75mA max ICPO