Features and Benefits
- 1.6V to 5.5V Input Voltage Range
- Internal Soft-Start
- Selectable 1.7MHz or 2.6MHz Constant Frequency Operation
- Internal Oscillator can be Synchronizable to an External Clock, 1MHz to 3MHz Range
- High Efficiency: Up to 95%
- Very Low Quiescent Current: Only 65µA During Burst Mode® Operation
- 600mA Output Current (VIN = 1.8V, VOUT = 1.2V)
- 750mA Peak Inductor Current
- No Schottky Diode Required
- Low Dropout Operation: 100% Duty Cycle
- 0.613V Reference Voltage
- Stable with Ceramic Capacitors
- Shutdown Mode Draws <1µA Supply Current
- Current Mode Operation for Excellent Line and Load Transient Response
- Overtemperature Protection
- Available in a Low Profile (0.75mm) 8-Lead (3mm × 3mm) DFN Package
The LTC3409 is a high efficiency, monolithic synchronous buck regulator using a constant frequency, current mode architecture. The output voltage is adjusted via an external resistor divider.
Fixed switching frequencies of 1.7MHz and 2.6MHz are supported. Alternatively, an internal PLL will synchronize to an external clock in the frequency range of 1MHz to 3MHz. This range of switching frequencies allows the use of small surface mount inductors and capacitors, including ceramics.
Supply current during Burst Mode operation is only 65µA dropping to <1µA in shutdown. The 1.6V to 5.5V input voltage range makes the LTC3409 ideally suited for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd or NiMH battery-powered applications. 100% duty cycle capability provides low dropout operation, extending battery life in portable systems. Burst Mode operation can be user enabled, increasing efficiency at light loads, further extending battery life.
The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Internal soft-start offers controlled output voltage rise time at start-up without the need for external components.
Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131.
- Cellular Phones
- Digital Cameras
- MP3 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)
Demonstration circuit 828 is a step-down converter using the LTC3409 monolithic synchronous buck regulator. The DC828 has an input voltage range of 1.6V to 5.5V and is capable of delivering up to 600mA of output current at a minimum input voltage of 1.8V. The jumper-selectable output voltage can be set to 1.2V, 1.5V or 1.8V.
Tools & Simulations
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:
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.
LTpowerCAD Project Files
Design tools for the following parts are available in LTpowerCAD:
Technical Articles (2)
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.
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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.