Alternative Parts


Features and Benefits

  • ±1.2% accuracy over line and load regulations @ 25°C
  • Ultralow dropout voltage: 120 mV typical @ 100 mA
  • Requires only COUT = 0.47 μF for stability
  • anyCAP LDOs are stable with all types of capacitors (including MLCC)
  • Current and thermal limiting
  • Low noise
  • Low shutdown current: 1 μA
  • 2.8 V to 12 V supply range
  • −20°C to +85°C ambient temperature range
  • Several fixed voltage options
  • Ultrasmall 5-lead SOT-23 package
  • Excellent line and load regulations

Product Details

The ADP3309 is a member of the ADP330x family of precision low dropout anyCAP voltage regulators. It is pin-for-pin and functionally compatible with National’s LP2981, but offers performance advantages. The ADP3309 stands out from conventional LDOs with a novel architecture and an enhanced process. Its patented design requires only a 0.47 μF output capacitor for stability. This device is stable with any type of capacitor regardless of its equivalent series resistance (ESR) value, including ceramic types for space restricted applications. The ADP3309 achieves ±1.2% accuracy at room temperature and ±2.2% overall accuracy over temperature, line, and load regulations. The dropout voltage of the ADP3309 is only 120 mV (typical) at 100 mA. This device also includes a current limit and a shutdown feature. In shutdown mode, the ground current is reduced to ~1 μA.

The ADP3309 operates with a wide input voltage range from 2.8 V to 12 V and delivers a load current in excess of 100 mA. The ADP3309 anyCAP LDO offers a wide range of output voltages.


  • Cellular telephones
  • Notebook, palmtop computers
  • Battery-powered systems
  • PCMCIA regulator
  • Bar code scanners
  • Camcorders, cameras

Product Lifecycle icon-not-recommended Not Recommended for New Designs

This designates products ADI does not recommend broadly for new designs.

Tools & Simulations

Design Tools

ADI Linear Regulator Design Tool and Parametric Search

Microsoft Excel download tool from ADIsimPower to generate a power supply design complete with a schematic, bill of materials, and performance specifications.

Design Resources

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PCN-PDN Information

Sample & Buy

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