LTC3780 buck-boost controller

Linear Technology has introduced the LTC3780, a buck-boost switching regulator controller that operates from input voltages above, below or equal to the output voltage.

Until now, high power buck-boost circuits have relied on transformers or two DC/DC converters - one for step-up (boost) and the other for step-down (buck) conversion.

This device operates using a single inductor and can deliver output power up to 75 W; a 4-switch synchronous rectification delivers efficiencies up to 97%.

The constant frequency current mode architecture allows a phase-lockable frequency of up to 400 kHz. With a wide 4 to 30 (36 V max) input and 0.8 to 30 V output range and transitions between operating modes, the device is suitable for automotive, telecom and battery-powered systems.

The device uses a proprietary current control architecture for constant frequency operation in buck or boost mode. In addition, fault protection is provided for overvoltage, over current and short circuit conditions in all modes. It offers three operating modes: constant frequency, burst mode operation and discontinuous current.