Maxim MAX11068 battery-monitoring IC

Maxim has introduced 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. It employs a SMBus-laddered communication bus that allows multiple 11068s to be daisy chained together without isolators.

This reduces battery-management system costs by up to 80%, while simplifying battery-pack design and precisely balancing cells for maximum energy delivery.

Offering accuracy, ultra-low power consumption, built-in safety and diagnostic features and configurability, the device is claimed to solve the problems associated with safely monitoring large battery stacks and accurately balancing cells.

The IC'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 digitise the cell voltages.

The device employs a two-phase scanning approach to collect cell measurements and correct them for errors.

This delivers cell-measurement simultaneity, allowing all cell-measurement samples of a 120-cell pack to be co-sited within 10 µs. This ensures accuracy in the face of extreme system noise.