High-voltage battery sensor extends Li-ion battery life

October 04, 2012 // By Christoph Hammerschmidt
Lithium-ion batteries are difficult to handle; they need to be constantly monitored. Chipmaker Maxim Integrated Products has introduced the fourth generation of its high-voltage sensor for drivetrain batteries in e-cars. The MAX17823 features a full package of integrated safety diagnosis functions according to the safety standard ISO26262. The device contributes to extending the driving range of electric vehicles while at the same time optimizing the safety and reliability of batteries and fuel cells.

The device is also equipped with a proprietary UART communication interface with differential PHY. With this interface, the chip offers excellent EMI behaviour as required for automotive environments. It does away with expensive digital isolators or optocouplers and facilitates uninterrupted cell monitoring even when the battery is disconnected for maintenance. An innovative switch-off system puts all downstream devices into sleep mode with power consumption of less than 1µA if the power supply to the host microcontroller is disconnected. ASIL D safety requirements are met through the precise measurements of up to 96 cells in an extremely fast cycle of 100 measurements per second. The hot-plug capability at the battery connections guarantees highest levels of reliability for design and production of battery management systems (BMS).

The device measures the voltages at an accuracy of 2mV or better. Comprehensive intelligent diagnosis functions prevent the system from premature shutdown. The daisy-chain design of the UART supports cable lengths of up to 3 meters and meets highest industrial and automotive EMI requirements. The operating temperature range covers the span from -40°C to +105°C. The device comes in an LQFP package.

For more information, visit http://www.maximintegrated.com/datasheet/index.mvp/id/7816