Linear Technology's LTC3531/-3.3/-3.0 is a synchronous buck-boost converter that delivers up to 200 mA of output current to a fixed regulated output with inputs above, below, or equal to the output voltage. The topology incorporated in the converter provides continuous transitions through all of the operating modes, making it suitable for single cell Li-Ion or dual cell alkaline/NiCad/NiMH applications that must maintain a constant output voltage even as the battery voltage declines below the output. In many cases, this can add up to 25% more battery run-time. The combination of three tiny externals and a 3- by 3-mm DFN or ThinSOT package provide a low-profile footprint.
The LTC3531/-3.3/-3.0 implements a four switch, single inductor architecture to deliver efficiencies over 90%. Burst-mode operation delivers a 16-ΜA quiescent current, while shutdown current is below 1 ΜA. Other features include current limiting, thermal shutdown, and output disconnect.
The LTC3531 is available from stock in an 8-lead DFN package. The LTC3531-3.0 or LTC3531-3.3 is available in either an 8-lead DFN or 6-lead ThinSOT. Pricing for all versions is $1.95 for 1000-piece quantities. For more information, visit www.linear.com.