Overview
Features and Benefits
- High Efficiency Dual Step-Down Outputs: Up to 96%
- 300mA Output Current per Channel at VIN = 3V
- Automatic Low Ripple Burst Mode Operation (20mVP-P).
- Only 40µA Quiescent Current During Operation (Both Channels)
- 2.25MHz Constant-Frequency Operation
- 2.5V to 5.5V Input Voltage Range
- Low Dropout Operation: 100% Duty Cycle
- Internally Compensated for All Ceramic Capacitors
- Independent Internal Soft-Start for Each Channel
- Current Mode Operation for Excellent Line and Load Transient Response
- 0.6V Reference Allows Low Output Voltages
- Short-Circuit Protected
- Ultralow Shutdown Current: IQ < 1µA
- Low Profi le (0.75mm) 8-Lead 3mm × 2mm DFN Package
Product Details
The LTC3547 is a dual, 2.25MHz, constant-frequency, synchronous step-down DC/DC converter in a tiny 3mm × 2mm DFN package. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Low output voltages are supported with the 0.6V feedback reference voltage. Each regulator can supply 300mA continuous output current.
The input voltage range is 2.5V to 5.5V, making it ideal for Li-Ion and USB powered applications. Supply current during operation is only 40µA and drops to < 1µA in shutdown. Automatic Burst Mode® operation increases efficiency at light loads, further extending battery life.
An internally set 2.25MHz switching frequency allows the use of tiny surface mount inductors and capacitors. Internal soft-start reduces inrush current during startup. All outputs are internally compensated to work with ceramic capacitors. The LTC3547 is available in a low profile (0.75mm) 3mm × 2mm DFN package.The LTC3547is also available in a fixed output voltage configuration,eliminating the need for the external feedback networks
Applications
- Cellular Telephones
- Digital Still Cameras
- Wireless and DSL Modems
- PDAs/Palmtop PCs
- Portable Media Players
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
-
DC1013A - 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.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
LTC3547
LTC3547-1
LTC3547B
LTC3547B-1
LTpowerCAD
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
To open the project file for this circuit:
Step 1: Download and install LTpowerCAD on your computer.
Step 2: Click on the link(s) in the section below to download part-specific project files.
Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.
Design tools for the following parts are available in LTpowerCAD:
LTC3547
Product Recommendations
LTC3547 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 |
|---|---|---|---|---|
| LTC3547EDDB#TRMPBF | Material Declaration | Reliability Data | 8-Lead DFN (3mm x 2mm w/ EP) | |
| LTC3547EDDB#TRPBF | Material Declaration | Reliability Data | 8-Lead DFN (3mm x 2mm w/ EP) | |
| LTC3547EDDB-1#TRMPBF | Material Declaration | Reliability Data | 8-Lead DFN (3mm x 2mm w/ EP) | |
| LTC3547EDDB-1#TRPBF | Material Declaration | Reliability Data | 8-Lead DFN (3mm x 2mm w/ EP) | |
| Wafer Fabrication Data | R415 Reliability Data |
Support & Discussions
Sample & Buy
Ordering FAQs
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Buy Now Pricing
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List Pricing
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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.