Overview
Features and Benefits
- Dynamically Adjustable Output from 0.3V to 3.5V
- 600mA Output Current
- Internal 0.08Ω P-Channel MOSFET Bypass Transistor
- High Efficiency: Up to 96%
- 1.5MHz Constant Frequency Operation
- No Schottky Diode Required
- Low Dropout Operation: 100% Duty Cycle
- 2.5V to 5V Input Voltage Range
- Shutdown Mode Draws <1µA Supply Current
- Current Mode Operation for Excellent Line and Load Transient Response
- Overtemperature Protected
- Available in 8-Lead 3mm x 3mm DFN Package
Product Details
The LTC3408 is a high efficiency monolithic synchronous buck regulator optimized for WCDMA power amplifier applications. The output voltage can be dynamically programmed from 0.3V to 3.5V. At VOUT > 3.6V an internal 0.08Ω bypass P-channel MOSFET connects VOUT directly to VIN, eliminating power loss through the inductor.
The input voltage range is 2.5V to 5V making the LTC3408 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.
Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode.
The LTC3408 is available in a low profile (0.75mm) 8-lead 3mm × 3mm DFN package.
Applications
- WCDMA Cell Phone Power Amplifiers
- Wireless Modems
Product Categories
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 & Resources
-
R415 Reliability Data3/23/2018
-
DC645A - Demo Manual9/24/2009
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:
Product Recommendations
LTC3408 Companion Parts
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.View our quality and reliability program and certifications for more information.
Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
---|---|---|---|---|
LTC3408EDD#PBF | Material Declaration | Reliability Data | 8-Lead DFN (3mm x 3mm x 0.75mm w/ EP) | |
LTC3408EDD#TRPBF | Material Declaration | Reliability Data | 8-Lead DFN (3mm x 3mm x 0.75mm w/ EP) | |
Wafer Fabrication Data | R415 Reliability Data |
Support & Discussions
Sample & Buy
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Buy Now Pricing
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List Pricing
(*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
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Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.