45V 100mA LDO Offers 30µVRMS Noise, Programmable Current Limit & Diagnostic Information

Sep 14 2009 - MILPITAS, CA
  • Linear Technology Corporation announces the LT3050, a high voltage, low noise, low dropout voltage linear regulator offering precision, programmable current limit and diagnostic capability. The device delivers up to 100mA output current with a 340mV dropout voltage at full load. The LT3050 features a wide 2V to 45V input voltage range, delivering adjustable output voltages from 0.6V to 44.5V. A single capacitor at the REF/BYP pin provides programmable low noise operation—nly 30µVRMS across a wide bandwidth of 10Hz to 100kHz—and reference soft start functionality, preventing output voltage overshoot at turn-on. Output voltage tolerance is highly accurate at ±2% over line, load and temperature.


    The LT3050 provides several diagnostic and safety functions. A single resistor at the IMAX pin programs current limit, accurate to ±5% over the full input voltage and temperature range. Also, a single resistor at the IMIN pin programs a minimum output current detector, useful for identifying open-circuit conditions. Furthermore, a current monitor function sources current equal to 1/100th of output current, allowing the user to measure output current or calculate the device's power dissipation. A logic Fault pin asserts low if the LT3050 is in current limit, operating below its minimum output current (open-circuit) or is in thermal shutdown. Moreover, the LT3050's internal protection circuitry includes reverse-battery protection, reverse-output protection, reverse-current protection, internal default current limiting and thermal limiting.

    The LT3050 operates with a very small, low cost, 2.2µF ceramic output capacitor, optimizing stability and transient response. This tiny external capacitor can be used without the addition of series resistance (ESR) as is common with many other regulators. The LT3050's wide input and output voltage ranges, fast transient response, low quiescent current of 50µA (operating) and < 1µA (in shutdown) make it an excellent choice for active antenna supplies, industrial power supplies, battery-powered systems requiring optimum run time, and high reliability power supplies requiring diagnostic information and protection functions.

    The LT3050EDDB & LT3050IDDB are housed in the 12-lead 2mm × 3mm DFN package, while the LT3050EMS8E & LT3050IMS8E are available in the 12-lead thermally enhanced MSOP package, all offering a compact footprint. Both "E" and "I" grade versions are available from stock with an operating junction temperature of –40ºC to +125ºC, while the "MP" grade operates from –55ºC to +125ºC (MSOP package only, LT3050MPMS8E) . 1,000 piece pricing starts at $1.55 & $1.75 each for the DFN package E and I grades, respectively, and $1.55, $1.75 and $4.19 each for the MSOP package E, I and MP grades, respectively. For more information, visit www.linear.com.

    Summary of Features: LT3050

    • Output Current: 100mA
    • Dropout Voltage: 340mV
    • Input Voltage Range: 2V to 45V
    • Programmable Precision Current Limit: ±5%
    • Programmable Minimum IOUT Detector
    • Output Current Monitor: 1/100th of IOUT
    • Fault Indicator: Current Limit, Minimum IOUT or Thermal Limit
    • Low Noise: 30µVRMS (10Hz to 100kHz)
    • Adjustable Output (VREF = VOUT(MIN) = 0.6V)
    • Reference Soft Start Capability Prevents Output Voltage Turn-on Overshoot
    • Output Tolerance: ±2% Over Line, Load and Temperature
    • Stable with Low ESR, Ceramic Output Capacitors (2.2µF minimum)
    • Shutdown Current: <1µA
    • Reverse Battery and Reverse Current Protection
    • Thermal Limit Protection
    • 12-Lead 2mm × 3mm DFN & MSOP Packages

    45VIN, 0.6VOUT 100mA Ultralow Noise LDO with Diagnostics


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