LTC3615 - Dual 4MHz, 3A Synchronous Step-Down DC/DC Converter
Features
- High Efficiency: Up to 94%
- Dual Outputs with 2 × 3A Output Current Capability
- Low Output Ripple Burst Mode® Operation: IQ = 130μA
- 2.25V to 5.5V Input Voltage Range
- ±1% Output Voltage Accuracy
- Output Voltages Down to 0.6V
- Programmable Slew Rate at Switch Pins
- Low Dropout Operation: 100% Duty Cycle
- Shutdown Current ≤1μA
- Adjustable Switching Frequency Up to 4MHz
- Internal or External Compensation
- Selectable Pulse-Skipping/Forced Continuous/ Burst Mode Operation with Adjustable Burst Clamp
- Optional Active Voltage Positioning (AVP) with Internal Compensation
- Selectable 0°/90°/180° (LTC3615) or selectable 140°/180° (LTC3615-1) Phase Shift Between Channels
- Fixed Internal and Programmable External Soft-Start
- Accurate Start-Up Tracking Capability
- DDR Memory Mode IOUT = ±1.5A
- Available in 4mm × 4mm QFN-24 and eTSSOP-24 Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3615/LTC3615-1 are dual 3A synchronous stepdown regulators using a current mode, constant-frequency architecture. The DC supply current is only 130μA (Burst Mode operation at no-load) while maintaining the output voltages, dropping to zero current in shutdown. The 2.25V to 5.5V input supply range makes the parts ideally suited for single Li-Ion applications. 100% duty cycle capability provides low dropout operation, which extends operating time in battery-operated systems.
The operating frequency is externally programmable up to 4MHz, allowing the use of small surface mount inductors. 0°, 90°, or 180° (LTC3615) or 140°/180° (LTC3615-1) of phase shift between the two channels can be selected to minimize input current ripple and output voltage ripple in a dual 3A or single 6A output configuration. Programmable slew rate limiting reduces EMI, and external synchronization can be applied up to 4MHz.
The internal synchronous switches increase efficiency and eliminate the need for external catch diodes, saving external components and board space.
The LTC3615/LTC3615-1 are offered in leadless 24-pin 4mm × 4mm QFN and thermally enhanced 24-pin eTSSOP packages.
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 |
|---|---|---|---|---|---|
| LTC3615EFE-1#PBF | TSSOP-24 | FE | E | 05-08-1771 | Yes |
| LTC3615EFE-1#TRPBF | TSSOP-24 | FE | E | 05-08-1771 | Yes |
| LTC3615EFE#PBF | TSSOP-24 | FE | E | 05-08-1771 | Yes |
| LTC3615EFE#TRPBF | TSSOP-24 | FE | E | 05-08-1771 | Yes |
| LTC3615EUF-1#PBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
| LTC3615EUF-1#TRPBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
| LTC3615EUF#PBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
| LTC3615EUF#TRPBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
| LTC3615HFE-1#PBF | TSSOP-24 | FE | H | 05-08-1771 | Yes |
| LTC3615HFE-1#TRPBF | TSSOP-24 | FE | H | 05-08-1771 | Yes |
| LTC3615HFE#PBF | TSSOP-24 | FE | H | 05-08-1771 | Yes |
| LTC3615HFE#TRPBF | TSSOP-24 | FE | H | 05-08-1771 | Yes |
| LTC3615HUF-1#PBF | 4x4 QFN-24 | UF | H | 05-08-1697 | Yes |
| LTC3615HUF-1#TRPBF | 4x4 QFN-24 | UF | H | 05-08-1697 | Yes |
| LTC3615HUF#PBF | 4x4 QFN-24 | UF | H | 05-08-1697 | Yes |
| LTC3615HUF#TRPBF | 4x4 QFN-24 | UF | H | 05-08-1697 | Yes |
| LTC3615IFE-1#PBF | TSSOP-24 | FE | I | 05-08-1771 | Yes |
| LTC3615IFE-1#TRPBF | TSSOP-24 | FE | I | 05-08-1771 | Yes |
| LTC3615IFE#PBF | TSSOP-24 | FE | I | 05-08-1771 | Yes |
| LTC3615IFE#TRPBF | TSSOP-24 | FE | I | 05-08-1771 | Yes |
| LTC3615IUF-1#PBF | 4x4 QFN-24 | UF | I | 05-08-1697 | Yes |
| LTC3615IUF-1#TRPBF | 4x4 QFN-24 | UF | I | 05-08-1697 | Yes |
| LTC3615IUF#PBF | 4x4 QFN-24 | UF | I | 05-08-1697 | Yes |
| LTC3615IUF#TRPBF | 4x4 QFN-24 | UF | I | 05-08-1697 | Yes |
| LTC3615MPFE-1#PBF | TSSOP-24 | FE | MP | 05-08-1771 | Yes |
| LTC3615MPFE-1#TRPBF | TSSOP-24 | FE | MP | 05-08-1771 | Yes |
| LTC3615MPFE#PBF | TSSOP-24 | FE | MP | 05-08-1771 | Yes |
| LTC3615MPFE#TRPBF | TSSOP-24 | FE | MP | 05-08-1771 | Yes |
| LTC3615MPUF-1#PBF | 4x4 QFN-24 | UF | MP | 05-08-1697 | Yes |
| LTC3615MPUF-1#TRPBF | 4x4 QFN-24 | UF | MP | 05-08-1697 | Yes |
| LTC3615MPUF#PBF | 4x4 QFN-24 | UF | MP | 05-08-1697 | Yes |
| LTC3615MPUF#TRPBF | 4x4 QFN-24 | UF | MP | 05-08-1697 | 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 |
|---|---|---|---|
| DC1435A | LTC3615EUF Demo Board (QFN) | 2.25V ≤ VIN ≤ 5.5V, VOUT1 = 1.8V to 3.3V @ 3A, VOUT2 = 1.2V to 1.8V @ 3A | Contact Factory | |
| DC1572A | LTC3615EFE Demo Board (TSSOP)| 2.25V ≤ VIN ≤ 5.5V, VOUT1 = 1.8V to 3.3V @ 3A, VOUT2 = 1.2V to 1.8V @ 3A | 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 pagesales office or authorized distributor.
Applications
- Point-of-Load Supplies
- Distributed Power Supplies
- Portable Computer Systems
- DDR Memory Termination
- Handheld Devices
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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:
LTC3615
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:
LTC3615
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.
