No RSENSE Synchronous DC/DC Controller with Output Tracking in a 3mm × 3mm DFN

Sep 20 2005 - MILPITAS, CA
  • Linear Technology Corporation announces the LTC3809-1, a No RSENSE synchronous step-down controller in a 3mm × 3mm DFN-10 (or MSOPE-10). The device's 550KHz frequency and current mode architecture with MOSFET VDS sensing eliminates the need for a current sense resistor while delivering efficiencies as high as 95%. The LTC3809-1's input voltage range of 2.75V to 9.8V makes it ideal for single or dual Li-Ion or multi-cell NiMH/NiCd/Alkaline applications, as well as standard 3.3V and 5V rails to operate in Burst Mode® with only 100uA of quiescent current, or in a pulse skipping or forced continuous mode for low out put voltage ripple.

    The LTC3809-1 off a user-adjustable tracking/soft-start input that smoothly ramps the out put voltage during startup. Other features include default internal soft-start circuitry, an auxiliary winding regulation and output over-voltage protection.

    The LTC3809EDD-1 and LTC3809EMSE-1 are both available from stock in 3mm × 3mm DFN-10 and MSOPE-10 packages, respectively. Pricing starts at $2.50 each in 1,000-piece quantities.

    Summary of Features: LTC3809-1

    • Programmable Output Voltage Tracking
    • No Current Sense Resistor Required
    • Constant Frequency Current Mode Operation for Excellent Line and load Transient Response
    • Wide VIN Range: 2.25V to 9.8V
    • 0.6V + 1.5% Reference
    • Low Dropout Operation: 100% Duty Cycle
    • Selectable Burst Mode®/Pulse Skipping/Forced Continuous Operation
    • Internal Soft-Start Circuitry
    • Selectable Maximum Peak Current Sense Threshold
    • Micropower Shutdown: lQ = 9uA
    • Tiny Thermally Enhanced Leadless (3mm × 3mm) DFN or 10-lead MOSP Package


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