Features and Benefits
- Wide VIN Range: 3.1V to 60V
- Wide VOUT Range: 0V to (VIN – 0.5V)
- Single Resistor VOUT Programming
- Integrated 110mΩ Top N-Channel/50mΩ Bottom N-Channel MOSFETs
- 95% Efficiency with 12VIN and 5VOUT
- Regulated IQ: 440μA, Shutdown IQ: 18μA
- Accurate Current Monitoring (±4%) without Sense Resistor
- Accurate Resistor Programmable Frequency (300kHz to 3MHz) with ±50% Frequency Sync Range
- Accurate Programmable Output Current
- Input Voltage Regulation for MPPT Applications
- ±0.8% Output Voltage Accuracy
- Peak Current Mode Operation
- Programmable Wire Drop Compensation
- Burst Mode® Operation, Forced Continuous Mode
- Internal Compensation and Programmable Soft-Start
- Overtemperature Protection
- Available in Thermally Enhanced 28-Lead (4mm × 5mm) QFN and TSSOP Packages
The LTC3649 is a high efficiency 60V, 4A synchronous monolithic step-down regulator. The regulator features a single resistor programmable output voltage, internal compensation and high efficiencies over a wide VOUT range.
The step-down regulator operates from an input voltage range of 3.1V to 60V and provides an adjustable rail-to-rail output range from (VIN – 0.5V) to ground while delivering up to 4A of output current. The switching frequency is also adjusted with an external resistor. A user-selectable mode input is provided to allow the user to trade off ripple noise for efficiency at light loads; Burst Mode operation provides the highest efficiency at light loads, while forced continuous mode provides low output ripple. The MODE/SYNC pin can also be used to allow the user to synchronize the switching frequency to an external clock.
The LTC3649 operates with a peak current mode architecture that allows for fast transient response with inherent cycle-to-cycle current limit protection. It also features programmable output current limit, current monitoring and input voltage regulation.
- Industrial Applications
- Automotive Applications
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 (2)
Demonstration circuit 2113A is a high input voltage, high efficiency synchronous monolithic buck converter featuring the LTC3649. The DC2113A has wide input voltage range from 3.1V up to 60V. The output voltage of the DC2113A can be set as to 3.3V or 5V. However, “USER SELECT” option of DC2113A allows output voltage to be as high as input voltage minus 0.5V, with certain modifications. DC2113A is capable of delivering up to 4A of output current. DC2113A supports three operation modes: Fixed-Frequency modulation, Burst Mode® operation and the user can synchronize it with external clock also. Fixed-Frequency mode of operation maximizes the output current, reduces output voltage ripple, and yields a low noise switching spectrum. Burst Mode operation employs a variable frequency switching algorithm that minimizes the no-load input quiescent current and improves efficiency at light loads.
Demonstration circuit 2112A is a high input voltage, high efficiency synchronous monolithic buck converter featuring the LTC3649 in a 28-lead UFD package. The DC2112A has wide input voltage range from 3.1V up to 60V. The output voltage of the DC2112A can be set as to 3.3V or 5V. However, the “USER SELECT” option of DC2112A allows output voltage to be as high as input voltage minus 0.5V, with certain modifications. DC2112A is capable of delivering up to 4A of output current. DC2112A supports three operation modes: Fixed-Frequency modulation and Burst Mode, user can synchronize it with an external clock also. Fixed-Frequency mode of operation maximizes the output current, reduces output voltage ripple, and yields a low noise switching spectrum. Burst Mode employs a variable frequency switching algorithm that minimizes the no-load input quiescent current and improves efficiency at light loads.
Design Notes (3)
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.
Design tools for the following parts are available in LTpowerCAD:
LTC3649 Companion Parts
Recommended Related Parts
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.
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.