LTC3646/LTC3646-1 - 40V, 1A Synchronous Step-Down Converter
Features
- Wide Input Voltage Range: 4.0V to 40V
- 1A Guaranteed Output Current
- High Efficiency: Up to 95%
- Wide Output Voltage Range
LTC3646: 2.0V to 30V
LTC3646-1: 0.6V to 15V - ±1% Accurate Reference Voltage
- Internal or External Compensation
- Switching Frequency Adjustable and Synchronizable: 200kHz to 3MHz
- Selectable High Efficiency Burst Mode® Operation or Forced Continuous Mode
- 14 Lead 3mm × 4mm DFN or Thermally Enhanced
- 16-Lead MSOP Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC®3646 is a high efficiency, step-down DC/DC converter with internal high side and synchronous power FETs. It draws only 140μA typical DC supply current in Burst Mode operation at no load while maintaining output voltage regulation.
The LTC3646 can supply up to a 1A load, and its combination of Burst Mode operation, integrated power switches and low quiescent current provides high efficiency over a broad range of load currents. Alternatively, it can be used in forced continuous mode for ripple sensitive applications.
The LTC3646 has a wide 4.0V to 40V input range and its patented controlled on-time architecture and 0.6V reference voltage allow for large step-down ratios without the risk of output overvoltage. The frequency may be set between 200kHz and 3.0MHz with a program resistor or synchronized to an external clock.
The internal soft-start, short-circuit protection and voltage rating make the LTC3646 a robust part ideal for high voltage applications.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC3646EDE-1#PBF | 4x3 DFN-14 | DE | E | 05-08-1708 | Yes |
| LTC3646EDE-1#TRPBF | 4x3 DFN-14 | DE | E | 05-08-1708 | Yes |
| LTC3646EDE#PBF | 4x3 DFN-14 | DE | E | 05-08-1708 | Yes |
| LTC3646EDE#TRPBF | 4x3 DFN-14 | DE | E | 05-08-1708 | Yes |
| LTC3646EMSE-1#PBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LTC3646EMSE-1#TRPBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LTC3646EMSE#PBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LTC3646EMSE#TRPBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LTC3646HDE-1#PBF | 4x3 DFN-14 | DE | H | 05-08-1708 | Yes |
| LTC3646HDE-1#TRPBF | 4x3 DFN-14 | DE | H | 05-08-1708 | Yes |
| LTC3646HDE#PBF | 4x3 DFN-14 | DE | H | 05-08-1708 | Yes |
| LTC3646HDE#TRPBF | 4x3 DFN-14 | DE | H | 05-08-1708 | Yes |
| LTC3646HMSE-1#PBF | MS-16E | MSE | H | 05-08-1667 | Yes |
| LTC3646HMSE-1#TRPBF | MS-16E | MSE | H | 05-08-1667 | Yes |
| LTC3646HMSE#PBF | MS-16E | MSE | H | 05-08-1667 | Yes |
| LTC3646HMSE#TRPBF | MS-16E | MSE | H | 05-08-1667 | Yes |
| LTC3646IDE-1#PBF | 4x3 DFN-14 | DE | I | 05-08-1708 | Yes |
| LTC3646IDE-1#TRPBF | 4x3 DFN-14 | DE | I | 05-08-1708 | Yes |
| LTC3646IDE#PBF | 4x3 DFN-14 | DE | I | 05-08-1708 | Yes |
| LTC3646IDE#TRPBF | 4x3 DFN-14 | DE | I | 05-08-1708 | Yes |
| LTC3646IMSE-1#PBF | MS-16E | MSE | I | 05-08-1667 | Yes |
| LTC3646IMSE-1#TRPBF | MS-16E | MSE | I | 05-08-1667 | Yes |
| LTC3646IMSE#PBF | MS-16E | MSE | I | 05-08-1667 | Yes |
| LTC3646IMSE#TRPBF | MS-16E | MSE | I | 05-08-1667 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
sales office or authorized distributor.Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1731A-A | LTC3646 Demo Board (DFN) I 4V ≤ VIN ≤ 40V, Vout = 3.3V or 5V @ 1A | $150.00 | |
| DC1731A-B | LTC3646-1 Demo Board (DFN) | 4V ≤ VIN ≤ 40V, Vout = 3.3V or 5V @ 1A | $150.00 | |
| DC1820A-A | LTC3646 Demo Board (MSOP) | 4V ≤ VIN ≤ 40V, Vout = 3.3V or 5V @ 1A | $150.00 | |
| DC1820A-B | LTC3646-1 Demo Board (MSOP) | 4V ≤ VIN ≤ 40V, Vout = 3.3V or 5V @ 1A | Contact Factory | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3646HDE-1#PBF | 4x3 DFN-14 | H | $4.84 | $3.39 | Yes | |
| LTC3646HDE-1#TRPBF | 4x3 DFN-14 | H | $3.45 | Yes | ||
| LTC3646HDE#PBF | 4x3 DFN-14 | H | $4.84 | $3.39 | Yes | |
| LTC3646HDE#TRPBF | 4x3 DFN-14 | H | $3.45 | Yes | ||
| LTC3646IDE-1#PBF | 4x3 DFN-14 | I | $4.49 | $3.14 | Yes | |
| LTC3646IDE-1#TRPBF | 4x3 DFN-14 | I | $3.20 | Yes | ||
| LTC3646IDE#PBF | 4x3 DFN-14 | I | $4.49 | $3.14 | Yes | |
| LTC3646IDE#TRPBF | 4x3 DFN-14 | I | $3.20 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Point of Load Power Supply
- Intermediate Bus Power
- Automotive Applications
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Product Notifications
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
To launch a ready to run LTspice demonstration circuit for this part:
- Step 1: If you have not installed LTspice on this computer, download and install LTspice
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice does not automatically open after clicking the link above, 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
To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice:
LTC3646
LTC3646-1
LTpowerCAD
The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD
To open the project file for this circuit:
- Step 1: If you have not installed LTpowerCAD on this computer, download and install LTpowerCAD
- Step 2: Once LTpowerCAD is installed, click on the link(s) below to open the project file
- Step 3: If LTpowerCAD does not automatically open after clicking the link above, you can open the project file by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTpowerCAD and open the project file by selecting 'Open Project' from the 'File' menu
Design tools for the following parts are available in LTpowerCAD:
LTC3646
LTC3646-1
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
