Automotive battery monitor-balancer diagnoses to extend driving range
Performance in wired and wireless battery management systems can be improved using the BQ79616-Q1, high-accuracy battery monitor and balancer, says Texas Instruments.
Engineers can diagnose battery failures in high-voltage systems in half the time, achieve ASIL D certification and extend driving range in hybrid and electric vehicles, claims the company.
It has been designed to report high accuracy voltage measurements in systems up to 800V. It also streamlines Automotive Safety Integrity Level (ASIL) D compliance in hybrid electric vehicles (HEVs) and electric vehicles (EVs).
The BQ79616-Q1 address the two key challenges of automotive design, says TI, namely, filtering system level noise to accurately measure battery cell voltage and temperature, and being able to reliably reporting this information to the microcontroller. Achieving this not only improves battery safety but also maximises distance per charge in wired and wireless battery management systems, TI says.
The BQ79616-Q1 battery monitor and balancer is claimed to be the industry’s first to include a patented wake-up-at-fault feature. When paired with the BQ79600-Q1 SPI/UART communication interface, it enables total system shutdown when the vehicle is parked or turned off. This helps design engineers conserve battery power, improve cell balancing and support safety requirements.
The BQ79616-Q1 is the first in a family of battery monitors and balancers to support high accuracy monitoring for a spectrum of battery chemistries, including lithium-iron phosphate (LiFePO4). By enabling automotive manufacturers to more precisely measure battery state-of-charge and state-of-health, the cost of the battery can be reduced. The BQ79616-Q1’s integrated digital low-pass filter and ADC optimise signal measurement accuracy to delivering cell voltage measurements with less than 2mV of error, reports TI.
The monitor and balancer meets component-level requirements of ISO 26262, supporting ASIL D compliance for voltage measurement, temperature measurement and communication. This not only reduces the bill of materials and also software overhead. The BQ79616-Q1 is claimed to have the industry’s fastest time in diagnosing battery failures, at a rate of 100ms in 400V systems, to increase system reliability and battery safety.
Additionally, the BQ79616-Q1 offers robust EMC performance to withstand the harsh, noisy environments of HEVs and EVs without compromising the reliability of daisy-chain communication, says TI. The pin rating enables the monitor-balancer device to withstand high voltage transients and hot plug events and incorporates autonomous cell balancing to simplify thermal management.
The family of monitors and balancers offers multiple channel options in the same package, providing pin-to-pin compatibility and 100 per cent reuse of established software. The BQ79616-Q1 integrates busbar measurement, enabling engineers to maximise channel usage across various combinations of battery module sizes.
Combining the BQ79616-Q1 with the BQ79600-Q1, advises TI, engineers can design their battery management system in a closed-loop configuration with only one communication interface to further reduce component count.
The 16-channel BQ79616-Q1 is available now in a 10 x 10mm, 64-pin thermally enhanced TQFP.
TI also offers the BQ79616-Q1EVM evaluation module.
