Overview
Features and Benefits
- 1 mm height profile
- Compact PCB footprint
- Seamless transition between modes
- 38 μA typical quiescent current
- 2.5 MHz operation enables 1.5 μH inductor
- Input voltage: 2.3 V to 5.5 V
- Fixed output voltage: 2.8 V to 5.0 V
- See data sheet for additional features
Product Details
The ADP2503/ADP2504 are high efficiency, low quiescent current step-up/step-down dc-to-dc converters that can operate at input voltages greater than, less than, or equal to the regulated output voltage. The power switches and synchronous rectifiers are internal to minimize external part count. At high load currents, the ADP2503/ADP2504 use a current-mode, fixed frequency pulse-width modulation (PWM) control scheme for optimal stability and transient response. To ensure the longest battery life in portable applications, the ADP2503/ADP2504 have an optional power save mode that reduces the switching frequency under light load conditions. For wireless and other low noise applications where variable frequency power save mode may cause interference, the logic control input sync forces fixed frequency PWM operation under all load conditions.The ADP2503/ADP2504 can run from input voltages between 2.3 V and 5.5 V, allowing single lithium or lithium polymer cell, multiple alkaline or NiMH cells, PCMCIA, USB, and other standard power sources. The ADP2503/ADP2504 have fixed output options, or using the adjustable model, the output voltage can be programmed through an external resistor divider. Compensation is internal to minimize the number of external components.
During logic-controlled shutdown, the input is disconnected from the output and draws less than 1 μA from the input source. Operating as boost converters, the ADP2503/ADP2504 feature a true load disconnect function that isolates the load from the power source. Other key features include undervoltage lockout to prevent deep battery discharge, and soft start to prevent input current overshoot at startup.
Applications
Data Sheet, Rev. A, 08/09
Product Categories
Markets & Technology
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Healthcare
- Clinical Monitoring
- ECG Patient Monitoring
- EEG Measurement
- Medical Isolation and Patient Safety
- NiBP based on BCG and PPG
- NiBP based on ECG and PPG
- Respiration Measurement
- SpO2
- Health, Wellness and Fitness
- Portable Blood Analyzer
- Body Composition Measurement
- Body-Worn Insulin Pump
- Motion Sensing/Fall Detection
- Sport Watch
- Wearable Health Monitor
Product Lifecycle
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)
Documentation
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.

Models for the following parts are available in LTspice:
Design Tools
ADIsimPower is the fastest and most accurate Power Management design tool. ADI's Design Center lets you design your power circuits in three easy steps.
Microsoft Excel download tool from ADIsimPower to generate a power supply design complete with a schematic, bill of materials, and performance specifications.
Reference Designs (1)
Reference Materials
Informational (1)
Circuit Notes (1)
Technical Articles (1)
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.
PCN-PDN Information
Discussions
ADP2503 Discussions

Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.