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

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

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
Typical Application
LTC3780 Typical Application
LTC3780 Typical Application
Applications
  • Automotive Systems
  • Telecom Systems
  • DC Power Distribution Systems
  • High Power Battery-Operated Devices
  • Industrial Control
Packaging
LTC3780 Package Drawing
LTC3780 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC3780EG#PBFSSOP-24E$6.64$4.65
LTC3780EG#TRPBFSSOP-24E$4.75
LTC3780EUH#PBF5x5 QFN-32E$6.64$4.65
LTC3780EUH#TRPBF5x5 QFN-32E$4.75
LTC3780IG#PBFSSOP-24I$7.64$5.35
LTC3780IG#TRPBFSSOP-24I$5.45
LTC3780IUH#PBF5x5 QFN-32I$7.64$5.35
LTC3780IUH#TRPBF5x5 QFN-32I$5.45
LTC3780MPGSSOP-24MP$10.34$7.24
LTC3780MPG#PBFSSOP-24MP$10.34$7.24
LTC3780MPG#TRSSOP-24MP$7.30
LTC3780MPG#TRPBFSSOP-24MP$7.30
Demo Boards
Part NumberDescriptionPrice
DC1046ALTC3780EG/LTC4440ES6 Demo Board | Buck-Boost, Vin: 36V to 72V, Vout 48V/5A$225.00
DC1155ALTC3780EUH Demo Board | 6V ≤ VIN ≤ 32V, VOUT = 12V @ 2A$200.00
DC686ALTC3780EG Demo Board | Buck-Boost, 5V to 32Vin, Vout = 12V @ 5A max$150.00
Datasheet
Design Note
Reliability Data
LT Journal
Press Release
CAD Symbol
LTspice
LTpowerCAD
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