16-cell integrated Li-ion monitor and protector for high-power battery packs

December 22, 2015 // By Graham Prophet
Texas Instruments’ Highly integrated battery management IC monitors up to 256 cells in series; TI says it is the first integrated battery monitor and protector to measure 16 battery cells at one time. The bq76PL455A-Q1 provides highly accurate cell-voltage monitoring for large batteries and can enable a more intelligent battery management in electric vehicles, hybrid electric vehicles, and grid energy storage systems.

The bq76PL455A-Q1 enables accurate computation of a battery pack's state of charge and state of health by precisely measuring cell voltage and also provides active and passive cell-balancing support to extract the maximum amount of energy from the battery. Passive cell balancing compensates for charging voltage mismatches, while active cell balancing maximises the amount of each charge. For hybrid and electric vehicles, this can lead to a decreased production cost for manufacturers while supporting an increased mileage range for drivers.

System integrators use the bq76PL455A-Q1 to develop innovative battery management systems including considerations for efficiencies and safety. "Preh was pleased to work with TI to implement design features that differentiate our battery management system offering," said Dr. Joachim Wagner, Head of Product Management and Pre-Development, Preh GmbH . "We intend to use our solution in several automotive and non-automotive applications."

Features of the bq76PL455A-Q1 include;

Monitors 16 stacked cells: Allows the accurate monitoring and protection of large battery packs with up to 256 cells in a series. The bq76PL455A-Q1's isolated differential UART also enables designers to eliminate the need for expensive controller area network (CAN) and isolators, further reducing bill of materials.

Reduces printed circuit board (PCB) size and system cost: The high integration features of the bq76PL455A-Q1 allows designers to use a single device, while other solutions could require as many as four devices for a 48V system.

Features highly accurate cell-voltage monitoring: Enables accurate computation of state of charge and state of health.

Helps system integrators to achieve system level functional safety (e.g. ISO26262) goals: Overvoltage/under-voltage comparators with a separate voltage reference and built-in self-tests for defined internal functions, open-wire detection, etc. Safety documentation is available on www.ti.com.

Increases battery lifetime and range: The bq76PL455A-Q1 provides support for both passive and active balancing (in conjunction with TI's EMB1428Q switch-matrix gate driver and EMB1499Q bidirectional current DC/DC converter.)

The bq76PL455A-Q1 evaluation module ( bq76PL455EVM) and bq76PL455A-Q1-EVM-GUI-SW graphical