Buck-boost battery charging controller works with a variety of chemistries

Analog Devices Inc. has released the LT8491 buck-boost battery charging controller that features automatic maximum power point tracking (MPPT) for solar-powered charging, automatic temperature compensation, and I²C interface for telemetry and control. The LT8491 offers three selectable constant-current constant-voltage (CC-CV) charging profiles, making it suited for charging a variety of battery chemistry types including sealed lead acid, gel and flooded cells, and Li-Ion. All charge termination algorithms are provided onboard, which eliminates the need for software or firmware.

The LT8491 operates over a 6-V to 80-V input range and can produce a 1.3-V to 80-V battery float voltage output using a single inductor with four-switch synchronous rectification. The device is capable of charging currents as high as 10 A depending on the choice of external components, said ADI. The LT8491 may be paralleled with multiple LT8705 (80-V buck-boost controller) devices for higher power operation.

A key feature of the LT8491 is that it can do a sweep of the full operating range of a solar panel, finding the true maximum power point. When found, the LT8491 will operate at that true maximum power point, while using a dithering technique to track slow changes in the maximum point, said ADI.  These methods enable the LT8491 to use nearly all the power generated by a solar panel even in non-ideal operating environments, according to the company

Automatic temperature compensation is achieved by sensing an external thermistor thermally coupled to the battery. The I²C interface provides complete control of the charger as well as input/output voltage, current, and power values. The operating temperature range is -40°C to 125°C.

Applications range from solar-powered battery chargers and battery-equipped industrial or portable military equipment to Li-ion battery chargers to lead-acid battery charging.

Available in production volume, the LT8491 (7 x 11 mm, QFN-64 package) is priced at $10.35 each per 1,000 units. An evaluation kit is available.