Battery sensor supports vehicle reliability with AEC-Q100

Freescale Semiconductor has launched what it boasts as the industry's first general market AEC-Q100 qualified intelligent battery sensor that combines three measurement channels, a 16/32bit MCU, and a CAN protocol module in a single package.

The MM9Z1J638 battery sensor supports both conventional and emerging battery chemistries for automotive and industrial applications, the MM9Z1J638 battery sensor measures key battery parameters for monitoring state of health, state of charge and state of function for early failure prediction.

A flexible four-cell front end architecture supports conventional 12V lead acid batteries as well as emerging battery applications, such as 14V stacked cell Li-Ion, high voltage junction boxes, and 24V truck batteries.

Integrating a 16/32 bit S12Z microcontroller with 128K Flash, 8K RAM and 4K EEPROM together with a CAN protocol module, LIN interface and a three-channel analogue measurement front end, the battery sensor combines analogue, processor and communication functions in a single package to help lower total bill of materials and accommodate advanced battery monitoring algorithms. The analogue front end includes a two-channel, 16bit sigma delta (ΣΔ) analogue-to-digital converter (ADC) for simultaneous measurement of battery voltage and current, as well as a third 16bit ΣΔ ADC for temperature monitoring using the integrated sensor and redundant measurement plausibility checks to support functional safety.

The sensor's input battery voltage measurement capability supports a wide range up to 52V directly to the device as well as much higher voltage battery configurations when used with external voltage dividers. Its low operating duty cycle enables operation in low-power mode for a majority of the time to help lower average system power consumption. It is fully AEC-Q100 automotive qualified and designed to meet stringent automotive standards for ESD, EMC and zero defect quality levels.

Battery failure is one of the leading causes of vehicle breakdowns due to electrical system errors. Rising levels of electrical load in vehicles are placing increased strain on batteries as new, mission-critical requirements such as engine start-stop functionality become increasingly common. Start-stop requirements, together with others such as regenerative braking and intelligent alternator control, are driving demand for more precise sensing of the battery's state to provide early failure warnings.

"Our introduction of the industry's first single-package, automotive-qualified intelligent battery sensor with MCU and CAN components will help automakers cope with increasing algorithm complexity and data communication demands as cars become more connected and intelligent," said James Bates, senior vice president and general manager for Freescale's Analogue & Sensors Group.

Reference designs with integrated hardware and software support for the sensor enable development of new applications, including energy storage systems, uninterruptible power supplies, hospital equipment and alarm systems. Low-level drivers and BMS utility libraries are available to support custom battery modelling and shorten development cycles. The KIT9Z1J638EVM evaluation board is priced at $188.80 and demonstrates key features of the battery sensor. Reference design RD9Z1-638-4Li is priced at$220.80 and demonstrates product capabilities for 4-cell Li-Ion battery applications.

The battery sensor costs $3.61 in 10,000-unit quantities.

- Graham Prophet
??EE Times Europe