National Semiconductor | High-performance Analog

 

 LM2705   
Micropower Step-up DC/DC Converter with 150mA Peak Current Limit 		Click link to Download

Features

  • 150mA, 0.7Ω, internal switch
  • Uses small surface mount components
  • Adjustable output voltage up to 20V
  • 2.2V to 7V input range
  • Input undervoltage lockout
  • 0.01µA shutdown current
  • Small 5-Lead SOT-23 package

    • Description

    The LM2705 is a micropower step-up DC/DC in a small 5-lead SOT-23 package. A current limited, fixed off-time control scheme conserves operating current resulting in high efficiency over a wide range of load conditions. The 21V switch allows for output voltages as high as 20V. The low 400ns off-time permits the use of tiny, low profile inductors and capacitors to minimize footprint and cost in space-conscious portable applications. The LM2705 is ideal for LCD panels requiring low current and high efficiency as well as white LED applications for cellular phone back-lighting. The LM2705 can drive up to 3 white LEDs from a single Li-Ion battery. The low peak inductor current of the LM2705 makes it ideal for USB applications.


    Applications

  • LCD Bias Supplies
  • White LED Back-Lighting
  • Handheld Devices
  • Digital Cameras
  • Portable Applications

    • Also Recommended
    LM2731Higher Power (1.5A Switch) PWM In SOT-23
    LM3500▲Synchronous Rectification Boost (No External Diode)
    LM3508▲True Shutdown, Smaller Footprint, High PWM Frequency For Brightness Control And Avoiding Audio Band.
    LM2703▲350mA Switch Current Limit Version



    Typical Application
    click for larger image


    		Block Diagram
    click for larger image



    Typical Performance
    click for larger image


    Parameters / ValuesLM2705 LM3500 LM3508 LM2703
    Regulated LEDs3 4 4 4
    Total LED Current40 mA 70 mA 30 mA 60 mA
    Boost TypeInductive Inductive Inductive Inductive
    Efficiency (peak)80 % 85 % 85 % 80 %
    Input Min Voltage2.2 Volt 2.7 Volt 2.7 Volt 2.2 Volt
    Input Max Voltage7 Volt 7 Volt 5.5 Volt 7 Volt
    OutputMax Voltage20 Volt 21, 16 Volt 17.5 Volt 20 Volt
    Boost VoltageUnregulated Regulated Regulated Unregulated
    LED ConfigurationSeries Series Series Series
    Supply Current0.235 mA 1 mA 0.825 mA 0.235 mA
    Switching TypePFM PWM Fixed Freq PFM
    PWM BrightCtrlYes Yes Yes Yes
    Analog-V BrightCtrlNo No No No
    Ambient Light CompensationNo No No No
    RGB-LEDNo No No No
    Temperature Min-40 deg C -40 deg C -30 deg C -40 deg C
    Temperature Max85 deg C 85 deg C 85 deg C 85 deg C
    RegTypeSwitching Regulator WhiteLED Driver WhiteLED Driver Switching Regulator
    PowerWiseNo No Yes No

    Datasheets
    TitleSizeDateOther
    Language
    LM2705 Micropower Step-up DC/DC Converter with 150mA Peak Current Limit635
    Kbytes    		17-Jun-10日本語  

    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM2705MF-ADJ/NOPB

    LM2705MF-ADJ

    RoHS Status

    SOT-23    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide740
    DIGI-KEYWorldwide3342
    FARNELLEurope and Asia1029
    MOUSERWorldwide990
    NEWARKAmericas418
    RS COMPONENTSWorldwide490
    TAYLORAmericas740
    		$0.70 each at 1K+ pcsreel
    of
    1000
    LM2705MFX-ADJ/NOPB

    LM2705MFX-ADJ

    RoHS Status

    SOT-23    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$0.70 each at 1K+ pcsreel
    of
    3000

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM2705.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM2705 is located at RoHS Status.

    Part Number(s)
    (NSID)    		Weight
    (milligrams)    		TypePinsMSL RatingPeak ReflowRoHS
    Status    		CAD SymbolsModelsPackage
    Marking
    Format
    LM2705MF-ADJ/NOPB

    LM2705MF-ADJ
    		14.696
    14.801
    		SOT-2351
    1    		260
    260    		DetailDownloadN/A
    		S59B
    XTT
    LM2705MFX-ADJ/NOPB

    LM2705MFX-ADJ
    		14.696
    14.801
    		SOT-2351
    1    		260
    260    		DetailDownloadN/A
    		S59B
    XTT

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM2705.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM2705 is located at RoHS Status.

    CAD Symbols and Models
    Download LM2705 CAD Symbols
    		 Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM2705MF-ADJABCD15004268000639400011814314958
    LM2705MFX-ADJABCD15004268000639400011814314958

    Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

    For more information on Reliability Metrics, please click here.


    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM2705.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM2705 is located at RoHS Status.

    [Information as of 3-Feb-2012]
    Copyright © 2011 National Semiconductor Corporation