500mA, 1.25MHz Synchronous Boost Regulator Features Output Disconnect and Soft-Start in a 2mm × 2mm DFN Package

Jan 5 2006 -MILPITAS, CA
  • Linear Technology announces the LTC3427, a 1.25MHz, current mode, synchronous boost DC/DC converter with true output disconnect, inrush current limiting and integrated soft-start capability packaged in a 2mm × 2mm DFN-6. Its internal switches provide a 500mA current limit (min) and deliver output voltages as high as 5.25V from an input voltage range of 1.8V to 5V, making the device compatible with both Li-Ion and dual cell alkaline/NiMH applications. The LTC3427 delivers up to 200mA of continuous output current (at 3.3V) from dual alkaline cells. Its synchronous rectification enables efficiencies of up to 94%. Also, its 1.25MHz constant switching frequency minimizes switching noise and enables the use of a tiny low cost inductor and capacitors. The combination of a 2mm × 2mm DFN and tiny externals provides a very compact, low profile solution footprint required in battery powered handheld applications.

    The LTC3427 uses internal switches with an RDS(ON) of only 0.52 Ω N-Channel) and 0.57 Ω (P-Channel) to deliver efficiencies as high as 94%. The device's true output disconnect feature allows the output to be completely disconnected in shutdown. It also limits the inrush of current during start-up, minimizing surge currents seen by the input supply. Additional features include anti-ringing control, short-circuit protection, programmable soft-start, and thermal protection. The LTC3427 is ideal for boost applications requiring up to 200mA of output current, and where a small solution size and maximum battery run-time are defining factors.

    LTC3427EDC is available from stock in a 6-lead DFN package. 1,000-piece pricing starts at $1.75 each.

    Summary of Features: LTC3427EDC

    • High Efficiency: Up to 94%
    • 3.3V at 200mA from Two Alkaline Cells
    • 5V at 200mA from a Single Li-Ion Cell
    • Inrush Current Limiting and Soft-Start
    • Output Disconnect in Shutdown
    • 1.8V to 5V VIN Range
    • 1.8V to 5.25V VOUT Range
    • 1.25MHz Fixed Frequency, Low Noise PWM
    • Internal Synchronous Rectifier
    • Logic Controlled Shutdown (<1uA)
    • Anti-Ringing Control Minimizes EMI
    • Tiny External Components
    • Short-Circuit Protection
    • Low Profile (0.75mm × 2mm × 2mm) DFN Package
    LTC3427 PR Image

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