Diodes Incorporated

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300MA Low-Noise CMOS LDO

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The AP139 is a positive voltage linear regulator utilizing CMOS technology. The features that include low quiescent current (45μA typ.), low dropout voltage, and high output voltage accuracy, make it ideal for battery applications. EN input connected to the device will produce a low bias current. The space-saving SOT25 package is attractive for “pocket” and “hand held” applications. This rugged device has both thermal shutdown, and current limit protections to prevent device failure under the “worst” operating conditions. In a low noise, regulated supply application, a 10nF capacitor is necessary to be placed in between Bypass and Ground. The AP139 is stable with a low ESR output capacitor of 1.0μF or greater.


  • Very Low Dropout Voltage
  • Low Current Consumption: Typ. 45μA, max. 60uA
  • Output Voltage: 1.5V, 1.8V, 2.0V, 2.5V, 2.8V, 3.0V 3.3V, and 3.5V
  • Guaranteed 300mA Output
  • Input Range from 2.7 up to 5.5V
  • Thermal Shutdown
  • Current Limiting
  • Stability with Low ESR Capacitors
  • Low Temperature Coefficient
  • Lead Free Package: SOT25
  • SOT25: Available in “Green” Molding Compound (No Br, Sb)
  • Lead Free Finish/RoHS Compliant
  • Application(s)

  • Personal Communication Devices
  • Home Electric/Electronic Appliances
  • PC Peripherals
  • Battery-Powered Devices
  • Product Specifications

    Product Parameters

    Compliance (Only Automotive supports PPAP) Standard
    Output options Fixed
    Iout (A) 0.3
    Vin (Max) (V) 5.5
    Vin (Min) (V) 2.7
    Vout (min) 1.5
    Vout (max) 3.5
    Fixed Vout (V) 1.5, 1.8, 2.0, 2.5, 2.8, 3.0, 3.3, 3.5
    Iq (typ) (µA) 45
    Accuracy 25C 2%
    VDROPOUT (Max) (V) at Max Current and Max Ouput Voltage 0.45
    PSRR (dB) 1kHz 75
    Operating Temperature (Ambient) (°C) -40 to 85 (°C)
    Enable Active H
    Channels 1
    Output Discharge no
    Iq (max)(µA) 60
    VCTL function no

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