Stand-alone or I²C-controlled 70-V bidirectional buck-boost charge controller with MPPT

The BQ25756 is a wide input voltage, switched-mode buck-boost Li-Ion, Li-polymer, or LiFePO 4 battery charge controller with bidirectional power flow support. The device offers high-efficiency battery charging over a wide voltage range with accurate charge current and charge voltage regulation, in addition to automatic charge preconditioning, termination, and charge status indication. The device integrates all the loop compensation for the buck-boost converter, thereby providing a high density solution with ease of use. In reverse mode, the device draws power from the battery and regulates the input terminal voltage with an added constant current loop for protection, supporting USB-PD EPR power profile.

Besides the I 2C host-controlled charging mode, the device also supports standalone charging mode via resistor programmable limits. Input current, charge current and charge voltage regulation targets can be set via the ILIMHIZ, ICHG and FB pins, respectively.