Milpitas, Calif. - Linear Technology's LT3466 is a dual step-up DC/DC converter that can drive up to 20 white LEDs from a (3.6-volt) lithium-ion source. Its high efficiency, current-mode and fixed-frequency operation ensure uniform LED brightness, low noise and maximum battery life, while on-chip Schottky diodes eliminate both the added cost and space requirements of external diodes. Its two independent converters are capable of driving asymmetric LED strings (up to 10 in series per converter) from an input voltage of 2.7 to 24 volts, suiting it to applications from handheld devices to automotives. The step-up converters have independent dimming and shutdown control of each string. Efficiency is as high as 81 percent.
The chip's 3-by-3 mm DFN package and tiny external components provide a very compact footprint for space-constrained handheld applications. Switching frequency can be set between 200 kHz and 2 MHz via a single resistor.
Additional features include internal soft-start/inrush current limiting, and open LED protection. The LT3466 is priced starting at $2.20 each in 1k pieces.