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Dual 500-mA LDO regulator with independent inputs provides ultralow noise benefits

Linear Technology Corporation has introduced a dual low noise, low dropout regulator with independent inputs and independent shutdown control for each channel.

The device delivers up to 500 mA per channel of continuous output current with a low dropout voltage of only 300 mV at full load. The LT3029 features a wide input voltage range of 1.8 V to 20 V, delivering output voltages as low as 1.215 V and up to 19.5 V. The device features ultralow noise of only 20 μVRMS across a wide bandwidth of 10 Hz to 100 kHz, and offers tracking/sequencing capability. Its full feature set and low quiescent current of 55 μA per regulator (operating) and <1 μA (in shutdown) make it an excellent choice for battery-powered "keep alive" systems that require optimum run time, in addition to microprocessor core logic supplies, tracking/sequencing supplies and general purpose voltage conversion.

The LT3029 operates with small, low cost, ceramic output capacitors, optimizing stability and transient response. The device is stable with only a 3.3 μF output capacitor versus older linear regulators that require between 10 μF and 100 μF to maintain stability. These tiny external capacitors can be used without the necessary addition of series resistance (ESR) as is common with many other regulators. Internal protection circuitry includes reverse-battery, no reverse current flow from output to input, current limiting with foldback and thermal shutdown. The thermal shutdown circuitry protects both channels if an overload or fault condition on either channel occurs.

Summary of Features: LT3029

  • Output Current: 500 mA per Channel
  • Low Dropout Voltage: 300 mV
  • Low Noise: 20 μVRMS (10 Hz to 100 kHz)
  • Low Quiescent Current: 55 μA per Channel
  • Wide Input Voltage Range: 1.8 V to 20 V
  • Adjustable Output Voltage: 1.215 V to 19.5 V
  • Stable with 3.3 μF Minimum Output Ceramic Capacitor

  • Low Shutdown Current <1 μA
  • Reverse Battery Protection
  • No Reverse Current Flow from Output to Input
  • Thermal Shutdown & Current Limiting with Foldback
  • Thermally Enhanced MSOP-16E & 4 mm x 3 mm DFN-16 Packages.

    Availability and Pricing

    The LT3029's compact packages offer thermal resistances equivalent to much larger conventional packages. The LT3029EMSE, LT3029IMSE, LT3029EDE and LT3029IDE are available from stock in a proprietary 16-lead thermally enhanced MSOP package and a 16-lead 4 mm x 3 mm DFN package, with operating junction temperature of -40 to +125 degrees C. The LT3029HMSE and LT3029MPMSE are available and offered in the MSOP package with extended operating junction temperatures of -40 to +150 degrees C and -55 to +125 degrees C, respectively. Pricing starts at $2.87, $3.13, $3.47, and $7.74 each for the E, I, H and MP grades, respectively, in 1,000-piece quantities.

    Datasheets:

    LT3029

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