200mA, Synchronous Buck-Boost DC/DC Converter Offers Extended Battery Run-Time for Handheld Applications

Dec 29 2005 -MILPITAS, CA
  • Linear Technology announces the LTC3531/–3.3/–3.0, a synchronous buck-boost converter that delivers up to 200mA of output current to a fixed regulated output with inputs above, below or equal to the output voltage. The topology incorporated in the LTC3531/–3.3/–3.0 provides continuous transitions through all of the operating modes, making it ideal 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 only three tiny externals and a 3mm × 3mm DFN or ThinSOT package provide a small and low profile solution footprint, typically required in battery powered handheld applications.


    The LTC3531/–3.3/–3.0 implements a four switch, single inductor architecture to deliver efficiencies over 90%. Burst Mode® operation delivers quiescent current of only 16uA and shutdown current is less than 1uA, further extending battery run-time. Other features include current limiting, thermal shutdown and output disconnect.


    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 package. Pricing for all versions is $1.95 each for 1,000-piece quantities.


    Summary of Features: LTC3531/-3.0/-3.3


    • Regulated Output with Input Above, Below or Equal to the Output
    • Single Inductor
    • Up to 90% Efficiency
    • VIN Range: 1.8V to 5.5V
    • 200mA at 3.3VOUT from 3.6V Input
    • 125mA at 3VOUT from 2.5V Input
    • Fixed VOUT Versions (TSOT, DFN): 3.3V, 3.0V
    • Adjustable VOUT Version (DFN): 2V to 5V
    • Burst Mode Operation
    • No External Compensation Required
    • Ultra Low Quiescent Current: 16uA, Shutdown Current <1uA
    • Only 3 External Components Required
    • Short-Circuit Protection
    • Output Disconnect in Shutdown
    • Available in 6-Pin ThinSOT and 3mm × 3mm DFN Packages
    LTC3531 PR Image

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