As some automakers such as Audi are turning to 48 V electrical systems to facilitate the integration of ever more electronic accessories, Austin, Texas-based Freescale Semiconductor (NYSE: FSL) has introduced a highly integrated 14-cell lithium-ion battery cell controller.
Freescale’s MC33771 battery cell controller and companion MC33664 isolated communications interface include fourteen cell balancing transistors, a current sensor with ±0.5% accuracy from milliamps to kiloamps, and a 2 Mbps communication transceiver interface, all integrated into a single 64-pin QFP package.
The solution’s built-in diagnostics help protect battery packs against critical fault conditions, and its transformer-coupled isolated high-speed transceiver eliminates the need for expensive isolated CAN busses to meet ASIL-C requirements.
“The robust design and comprehensive integration of our new battery cell controller reflects Freescale’s system-level approach to cost-effectively manage battery charging while helping to prevent failures and dangerous conditions,” said Freescale Senior VP James Bates. “This new battery cell controller leverages Freescale’s automotive heritage and history of creating highly integrated solutions to reduce the cost of meeting stringent safety requirements.”
The MC33771 incorporates many critical functions required for controlling a single 48 V battery pack, including the capability to synchronously measure currents and voltages with 2 millivolts of accuracy. Embedded functional verification and fault diagnostics enable compliance with ISO 26262 ASIL-C functional safety standards without additional external circuitry.
The MC33771, in combination with the MC33664 isolated communication device, supports optimal lifecycles for a variety of battery architectures, including centralized, distributed CAN and distributed daisy-chain topologies.
The new devices are sampling now, and versions for the automotive market are planned for production by Q3 2015. The MC33771 will be available for a suggested retail price of $4.86 – $10.95 in 10 kU quantities. The MC33664 will be available for a suggested retail price of $1.65 in 10 kU quantities.