Bidirectional PolyPhase Synchronous Buck or Boost Controller

The LTC3871/LTC3871-1 is a high performance bidirectional buck or boost switching regulator controller that operates in either buck or boost mode on demand. It regulates in buck mode from VHIGH-to-VLOW and boost mode from VLOW-to-VHIGH depending on a control signal, making it ideal for 48V/12V automotive dual battery systems. An accurate current programming loop regulates the maximum current that can be delivered in either direction. The LTC3871/LTC3871-1 allows both batteries to supply energy to the load simultaneously by converting energy from one battery to the other.

Its proprietary constant-frequency current mode architecture enhances the signal-to-noise ratio enabling low noise operation and provides excellent current matching between phases. Additional features include discontinuous or continuous mode of operation, OV/UV monitors, independent loop compensation for buck and boost operation, accurate output current monitoring and overcurrent protection. The LTC3871 and LTC3871-1 have different current limit foldback characteristics.

Applications

* Automotive 48V/12V Dual Battery Systems

* Backup Power Systems

* Unique Architecture Allows Dynamic Regulation of Input Voltage, Output Voltage or Current

* VHIGH Voltages Up to 100V

* VLOW Voltages Up to 30V

* Synchronous Rectification: Up to 97% Efficiency

* ADI-Proprietary Advanced Current Mode Control

* ±1% Voltage Regulation Accuracy Over Temperature

* Accurate, Programmable Output Current Monitoring and Regulation for Both Buck and Boost Operation