Overview

Features and Benefits

  • Peak efficiency: 95%
  • Discharge switch function
  • Fixed frequency operation: 3 MHz
  • Typical quiescent current: 18 μA
  • Maximum load current: 600 mA
  • Input voltage: 2.3 V to 5.5 V
  • Uses tiny multilayer inductors and capacitors
  • Current mode architecture for fast load and line transient response
  • 100% duty-cycle low-dropout mode
  • Internal synchronous rectifier
  • Internal compensation
  • For additional features please see the data sheet

Product Details

The ADP2109 is a high efficiency, low quiescent current stepdown dc-to-dc converter with an internal discharge switch that allows automatic discharge of the output capacitor in an ultra small 5-ball WLCSP package.

The total solution only requires three tiny external components. It uses a proprietary high-speed current mode, constant frequency PWM control scheme for excellent stability and transient response. To ensure the longest battery life in portable applications, the ADP2109 has a power save mode that reduces the switching frequency under light load conditions.

The ADP2109 runs on input voltages of 2.3 V to 5.5 V, which allow for single lithium or lithium polymer cell, multiple alkaline or NiMH cells, PCMCIA, USB, and other standard power sources. The maximum load current of 600 mA is achievable across the input voltage range.

The ADP2109 is available in fixed output voltages of 1.8 V, 1.2 V, and 1.0 V. All versions include an internal power switch and synchronous rectifier for minimal external part count and high efficiency. The ADP2109 has an internal soft start and internal compensation. During logic-controlled shutdown, the input is disconnected from the output and the ADP2109 draws less than 1 μA from the input source.

Other key features include undervoltage lockout to prevent deep battery discharge and soft start to prevent input current overshoot at startup. The ADP2109 is available in a 5-ball WLCSP.

Other key features include undervoltage lockout to prevent deep battery discharge and soft start to prevent input current overshoot at startup. The ADP2109 is available in a 5-ball WLCSP.

The ADP2108 provides the same features and operations as the ADP2109 without the discharge switch and is available in both WLCSP and TSOT packages.


Applications
  • PDAs and palmtop computers
  • Wireless handsets
  • Digital audio, portable media players
  • Digital cameras, GPS navigation units

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Evaluation Kits (1)

Tools & Simulations

LTspice

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

LTspice

Models for the following parts are available in LTspice:

adp2109-1
ADP2109-1.0
ADP2109-1.1
ADP2109-1.2
ADP2109-1.3
ADP2109-1.5
ADP2109-1.8
ADP2109-1.82
adp2109-2
ADP2109-2.3
ADP2109-2.5
adp2109-3
ADP2109-3.0
ADP2109-3.3

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Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.