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Battery-Monitoring IC Reduces BMS Cost By 80% In Hybrid, Electric Vehicles
MAXIM INTEGRATED Products introduces the MAX11068, a high-voltage, 12-cell, battery-monitoring IC for hybrid vehicles, electric vehicles, and any system that stacks long series strings of batteries. This highly integrated solution employs a proprietary SMBus(TM)-laddered communication bus that allows multiple MAX11068s to be daisy chained together without expensive isolators. This approach reduces battery-management system (BMS) cost by up to 80%, while simplifying battery pack design and precisely balancing cells for maximum energy delivery.
Offering world-class accuracy, ultra-low power consumption, built-in safety and diagnostic features, and plenty of configurability, the MAX11068 solves the problems associated with safely monitoring large battery stacks and accurately balancing cells. It is well suited for a wide spectrum of battery applications including automotive, industrial, power line, and battery backup.
The MAX11068's analog front-end combines a 12-channel voltage-measurement data-acquisition system with a high-voltage, fault-tolerant switch bank input. A high-speed, 12-bit ADC is used to digitize the cell voltages. The MAX11068 employs a two-phase scanning approach to collect cell measurements and correct them for errors. This technique delivers cell-measurement simultaneously, allowing all cell-measurement samples of a 120-cell pack to be co-sited within 10µs. This ensures high accuracy under extreme system noise. The MAX11068 delivers less than ±0.25% error over normal battery temperature ranges and ±20mV error over the full AEC-Q100 Type 2 temperature range.
Additionally, the MAX11068 offers a 10x reduction in power consumption (100µA, operating mode) to conserve battery life. A unique built-in shutdown feature reduces consumption to an ultra-low 1µA leakage, allowing the pack to be stored for many years without draining the battery.
Maxim Integrated Products
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