Automotive-qualified CAN transceiver offers galvanic isolation

March 21, 2013 // By Christoph Hammerschmidt
Hybrid electric and electric vehicles have one thing in common: They have batteries with several hundred volts. In order to implement measurement and control circuitry, designers have to separate areas with high and low voltage levels. NXP addresses this demand with an the ISO11898-2 compliant CAN transceiver - the first product of its kind to offer this level of integration at AEC-Q100 automotive grade quality.

The TJA1052i is designed for all types of CAN networks where high- and low-voltage networks co-exist and require galvanic isolation for safety reasons. Adding isolation to the CAN transceiver simplifies the design effort to safely bridge between high and low voltage levels. The TJA1052i provides protection against electric shocks, overvoltage, ground offset and reverse current, while improving signal integrity in noisy electromagnetic environments.

By integrating an existing market accepted CAN transceiver with a Galvanic Isolator in one package, this solution ensures matching dynamic parameters, reduces board space, improves signal performance, and increases overall reliability and cost-effectiveness. Historically, automotive OEMs and Tier 1 suppliers have used expensive Opto Couplers to isolate the CAN transceiver, with performance in such a standalone solution tending to degrade over time.

The TJA1052i is well-suited for the growing market of hybrid and full electric vehicles (H/EVs), where high and low voltage levels co-exist. H/EVs are equipped with multiple battery modules – typically controlled via CAN by the Battery Management System – which together can supply up to 500 Volts and also power other high-voltage applications such as Inverter, Start/Stop, DC/DC Converter, Charger and Air Conditioning systems. These systems need to communicate with other Electronic Control Units (ECUs) via the CAN Bus, and are typically operated from the 12V board net.

Isolated CAN products are also needed in industrial applications where ECUs controlling high voltage applications and other ECUs need to be connected to each other via the CAN bus. Application examples for the TJA1052i in non-automotive areas are industrial equipment, energy storage systems, building automation and H/EV charging stations.

The TJA1052i is ramping up in production with immediate effect.

For more information visit http://www.nxp.com/pip/TJA1052IT