The LTC3780IG 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 LTC3780IG 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.
Feature
- 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
Applications
- Automotive Systems
- Telecom Systems
- DC Power Distribution Systems
- High Power Battery-Operated Devices
- Industrial Control
