The LTC3538 from Analog Devices is a Synchronous Buck-Boost DC-DC Converter that converts an input voltage of 2.4 – 5.5 V to an output voltage of 1.8 – 5.25 V. It has a switching frequency of 1 MHz. This converter offers regulated output with input voltages above, below, or equal to the output voltage. It provides a continuous transfer function through all operating modes, making it perfect for single Lithium Ion or multicell Alkaline or NiMH applications. This converter features a continuous output current from a single lithium-ion/polymer cell. It utilizes a single inductor for both buck and boost operations, simplifying the circuit design and reducing component count.

This converter benefits from internal soft-start, short circuit protection, and output disconnect in shutdown. It is available in a surface-mount package that measures 2 x 3 mm and is ideal for miniature hard disk drives, MP3 players, digital cameras, cellular handsets, PDAs, handheld PC, and GPS receiver applications.