Charge pump

Sipex Corporation has expanded its family of LED drivers with the SP6686, a current regulated buck/boost charge pump delivering 400mA.

Providing two independently adjustable and selectable output current levels for flash and torch modes, the SP6686 has been developed for camera flash applications in cell phones.

Operating at a 2.4 MHz switching frequency, the SP6686 requires only three tiny external capacitors (0.47µF, 1µF, and 2.2µF).

The SP6686 delivers up to 94% efficiency thanks to a proprietary feature that enables the IC to automatically transition from the linear buck mode to the 2x boost mode based on the battery input voltage. This also ensures the current does not depend on the LED forward voltage.

An extremely low output equivalent resistance and reference voltage allows for the highest white LED flash brightness and an ultra low dropout voltage. The SP6686 also features a very low shutdown current of 1µA, an automatic soft-start mode to limit inrush current, as well as over current, over voltage and thermal-shutdown control.