Dual 2.25MHz Synchronous Step-Down DC/DC Converter in 3mm × 3mm DFN Delivers up to 600mA per Channel

May 23 2007 - MILPITAS, CA
  • Linear Technology announces the LTC3419/-1, a dual output, high efficiency, 2.25 MHz synchronous buck regulator that can deliver up to 600mA of continuous output current from each channel. Using a constant frequency current mode architecture, the LTC3419 operates from an input voltage range of 2.5V to 5.5V, making it ideal for single-cell Li-Ion, multi-cell alkaline or NiMH applications. It can generate two independent output voltages as low as 0.6V, enabling it to power the latest generation of low voltage DSPs and microcontrollers. A fixed output voltage version, the LTC3419-1 is also available with fixed 1.575V and 1.8V outputs. Both versions use a switching frequency of 2.25 MHz, which allows for the utilization of tiny, low cost ceramic capacitors and inductors less than 1 mm in height. The combination of dual architecture, the tiny externals and a 3mm × 3mm DFN (or MSOP-10) package make the LTC3419/-1 a very compact synchronous step-down solution for dual output voltage rails.

    The LTC3419/-1 uses internal switches with an RDS(ON) of only 0.4Ω to deliver efficiencies as high as 96%. It also utilizes low dropout 100% duty cycle operation to allow output voltages equal to VIN, further extending battery run-time. No load quiescent current is only 35uA (both channels), and <1uA in shutdown, ensuring optimal battery life. 

    The LTC3419EDD and LTC3419-1EDD are both available from stock in a DFN-8. The LTC3419EMS and LTC3419EMS-1 are available from stock in an MSOP package. Pricing for all versions starts at $1.95 each for 1,000-piece quantities.

    Summary of Features: LTC3419/-1

    • 600mA Current per Channel at VIN = 3V
    • High Efficiency Dual Step-Down Outputs: Up to 96%
    • Only 35uA Quiescent Current During Operation (Both Channels)
    • 2.25MHz Constant Frequency Operation
    • 2.5V to 5.5V Input Voltage Range
    • Low Dropout Operation: 100% Duty Cycle
    • No Schottky Diodes Required
    • Internally Compensated for All Ceramic Capacitors
    • Independent Internal Soft-Start for Each Channel
    • Available in Fixed Output Versions; 1.8V and 1.575V
    • Current Mode Operation for Excellent Line and Load Transient Response
    • 0.6V Reference Allows Low Output Voltages
    • User-Selectable Burst Mode Operation
    • Short-Circuit Protected
    • Ultralow Shutdown Current: IQ
    • Available in Small MSOP or 3mm × 3mm DFN-8 Packages

    Dual 2.25MHz, 600mA Synchronous Step-Down DC/DC Converter

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