LTC3780 - High Efficiency, Synchronous, 4-Switch Buck-Boost Controller


  • 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

Typical Application

LTC3780 Typical Application
LTC3780 Typical Application


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


For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC3780EG SSOP-24 G E 05-08-1640 (G24) RoHS
LTC3780EG#PBF SSOP-24 G E 05-08-1640 (G24) RoHS
LTC3780EG#TR SSOP-24 G E 05-08-1640 (G24) RoHS
LTC3780EG#TRPBF SSOP-24 G E 05-08-1640 (G24) RoHS
LTC3780EUH 5x5 QFN-32 UH E 05-08-1693 RoHS
LTC3780EUH#PBF 5x5 QFN-32 UH E 05-08-1693 RoHS
LTC3780EUH#TR 5x5 QFN-32 UH E 05-08-1693 RoHS
LTC3780EUH#TRPBF 5x5 QFN-32 UH E 05-08-1693 RoHS
LTC3780IG SSOP-24 G I 05-08-1640 (G24) RoHS
LTC3780IG#PBF SSOP-24 G I 05-08-1640 (G24) RoHS
LTC3780IG#TR SSOP-24 G I 05-08-1640 (G24) RoHS
LTC3780IG#TRPBF SSOP-24 G I 05-08-1640 (G24) RoHS
LTC3780IUH 5x5 QFN-32 UH I 05-08-1693 RoHS
LTC3780IUH#PBF 5x5 QFN-32 UH I 05-08-1693 RoHS
LTC3780IUH#TR 5x5 QFN-32 UH I 05-08-1693 RoHS
LTC3780IUH#TRPBF 5x5 QFN-32 UH I 05-08-1693 RoHS
LTC3780MPG SSOP-24 G MP 05-08-1640 (G24) RoHS
LTC3780MPG#PBF SSOP-24 G MP 05-08-1640 (G24) RoHS
LTC3780MPG#TR SSOP-24 G MP 05-08-1640 (G24) RoHS
LTC3780MPG#TRPBF SSOP-24 G MP 05-08-1640 (G24) RoHS

LTC3780 Package Drawing
LTC3780 Package Drawing

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
LTC3780EG SSOP-24 E $13.28 $9.30 No
LTC3780EG#PBF SSOP-24 E $6.64 $4.65 Yes
LTC3780EG#TR SSOP-24 E $9.50 No
LTC3780EG#TRPBF SSOP-24 E $4.75 Yes
LTC3780EUH 5x5 QFN-32 E $13.28 $9.30 No
LTC3780EUH#PBF 5x5 QFN-32 E $6.64 $4.65 Yes
LTC3780EUH#TR 5x5 QFN-32 E $9.50 No
LTC3780EUH#TRPBF 5x5 QFN-32 E $4.75 Yes
LTC3780IG SSOP-24 I $15.28 $10.70 No
LTC3780IG#PBF SSOP-24 I $7.64 $5.35 Yes
LTC3780IG#TR SSOP-24 I $10.90 No
LTC3780IG#TRPBF SSOP-24 I $5.45 Yes
LTC3780IUH 5x5 QFN-32 I $15.28 $10.70 No
LTC3780IUH#PBF 5x5 QFN-32 I $7.64 $5.35 Yes
LTC3780IUH#TR 5x5 QFN-32 I $10.90 No
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
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* 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 Linear Technology 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
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
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  • Automotive Systems
  • Telecom Systems
  • DC Power Distribution Systems
  • High Power Battery-Operated Devices
  • Industrial Control

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