Inductorless Multi Mode LED Charge Pump
Linear Technology Corporation announces the LTC3214, a fractional charge pump, high current white LED driver that delivers up to 500 mA of LED current. Its high efficiency multi-mode architecture automatically switches between 1x, 1.5x or 2x boost modes monitoring the voltage across the LED current source and switching modes only when ILED dropout is detected. This enables the LTC3214 to maximize efficiency (up to 94%) throughout the entire Li-Ion operating range. A 900 kHz switching frequency and a low external parts count provide a small footprint well suited for video and Flash applications in camera phones and other portable lighting applications. The LTC3214 employs built-in soft-start circuitry which prevents excessive inrush current during start-up. An ultra low dropout current source maintains accurate LED current as the input voltage approaches the LED forward voltage. The LTC3214 is available in a low profile (0.75 mm), 3 × 3 mm ten-lead DFN package.
Linear Technology Corporation