LTC3780 - High Efficiency, Synchronous, 4-Switch Buck-Boost Controller
Features
- Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT
- Wide VIN Range: 4V to 36V Operation
- Synchronous Rectification: Up to 98% Efficiency
- Current Mode Control
- ±1% Output Voltage Accuracy: 0.8V < VOUT < 30V
- Phase-Lockable Fixed Frequency: 200kHz to 400kHz
- Power Good Output Voltage Monitor
- Internal LDO for MOSFET Supply
- Quad N-Channel MOSFET Synchronous Drive
- VOUT Disconnected from VIN During Shutdown
- Adjustable Soft-Start Current Ramping
- Foldback Output Current Limiting
- Selectable Low Current Modes
- Output Overvoltage Protection
- Available in 24-Lead SSOP and Exposed Pad
(5mm × 5mm) 32-Lead QFN Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3780 is a high performance buck-boost switching regulator controller that operates from input voltages above, below or equal to the output voltage. The constant frequency current mode architecture allows a phase-lockable frequency of up to 400kHz. With a wide 4V to 30V (36V maximum) input and output range and seamless transfers between operating modes, the LTC3780 is ideal for automotive, telecom and battery-powered systems.
The operating mode of the controller is determined through the FCB pin. For boost operation, the FCB mode pin can select among Burst Mode® operation, Discontinuous mode and Forced Continuous mode. During buck operation, the FCB mode pin can select among Skip-Cycle mode, Discontinuous mode and Forced Continuous mode. Burst Mode operation and Skip-Cycle mode provide high efficiency operation at light loads while forced continuous mode and discontinuous mode operate at a constant frequency.
Fault protection is provided by an output overvoltage comparator and internal foldback current limiting. A Power Good output pin indicates when the output is within 7.5% of its designed set point.
Protected by U.S. Patents, including 5481178, 6304066, 5929620, 5408150, 6580258, patent pending on current mode architecture and protection
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 |
|---|---|---|---|---|---|
| LTC3780EG#PBF | SSOP-24 | G | E | 05-08-1640 (G24) | Yes |
| LTC3780EG#TRPBF | SSOP-24 | G | E | 05-08-1640 (G24) | Yes |
| LTC3780EUH#PBF | 5x5 QFN-32 | UH | E | 05-08-1693 | Yes |
| LTC3780EUH#TRPBF | 5x5 QFN-32 | UH | E | 05-08-1693 | Yes |
| LTC3780IG#PBF | SSOP-24 | G | I | 05-08-1640 (G24) | Yes |
| LTC3780IG#TRPBF | SSOP-24 | G | I | 05-08-1640 (G24) | Yes |
| LTC3780IUH#PBF | 5x5 QFN-32 | UH | I | 05-08-1693 | Yes |
| LTC3780IUH#TRPBF | 5x5 QFN-32 | UH | I | 05-08-1693 | Yes |
| LTC3780MPG | SSOP-24 | G | MP | 05-08-1640 (G24) | No |
| LTC3780MPG#PBF | SSOP-24 | G | MP | 05-08-1640 (G24) | Yes |
| LTC3780MPG#TR | SSOP-24 | G | MP | 05-08-1640 (G24) | No |
| LTC3780MPG#TRPBF | SSOP-24 | G | MP | 05-08-1640 (G24) | 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
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3780EG#PBF | SSOP-24 | E | $6.64 | $4.65 | Yes | |
| LTC3780EG#TRPBF | SSOP-24 | E | $4.75 | Yes | ||
| LTC3780EUH#PBF | 5x5 QFN-32 | E | $6.64 | $4.65 | Yes | |
| LTC3780EUH#TRPBF | 5x5 QFN-32 | E | $4.75 | Yes | ||
| LTC3780IG#PBF | SSOP-24 | I | $7.64 | $5.35 | Yes | |
| LTC3780IG#TRPBF | SSOP-24 | I | $5.45 | Yes | ||
| LTC3780IUH#PBF | 5x5 QFN-32 | I | $7.64 | $5.35 | Yes | |
| LTC3780IUH#TRPBF | 5x5 QFN-32 | I | $5.45 | Yes | ||
| LTC3780MPG | SSOP-24 | MP | $10.34 | $7.24 | No | |
| LTC3780MPG#PBF | SSOP-24 | MP | $10.34 | $7.24 | Yes | |
| LTC3780MPG#TR | SSOP-24 | MP | $7.30 | No | ||
| LTC3780MPG#TRPBF | SSOP-24 | MP | $7.30 | Yes | ||
| Buy Now • Request Samples | ||||||
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 |
|---|---|---|---|
| DC1046A | LTC3780EG/LTC4440ES6 Demo Board | Buck-Boost, Vin: 36V to 72V, Vout 48V/5A | $225.00 | |
| DC1155A | LTC3780EUH Demo Board | 6V ≤ VIN ≤ 32V, VOUT = 12V @ 2A | $200.00 | |
| DC686A | LTC3780EG Demo Board | Buck-Boost, 5V to 32Vin, Vout = 12V @ 5A max | $150.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LTC3780IG#PBF | SSOP-24 | I | $7.64 | $5.35 | Yes | |
| LTC3780IG#TRPBF | SSOP-24 | I | $5.45 | Yes | ||
| LTC3780IUH#PBF | 5x5 QFN-32 | I | $7.64 | $5.35 | Yes | |
| LTC3780IUH#TRPBF | 5x5 QFN-32 | I | $5.45 | Yes | ||
| LTC3780MPG#PBF | SSOP-24 | MP | $10.34 | $7.24 | Yes | |
| LTC3780MPG#TRPBF | SSOP-24 | MP | $7.30 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Automotive Systems
- Telecom Systems
- DC Power Distribution Systems
- High Power Battery-Operated Devices
- Industrial Control
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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:
LTC3780
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:
LTC3780
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.
