Battery fault

Battery stack fault monitor provides independent supervision of high voltage Li-Ion Strings


Linear Technology has announced the LTC®6801, a high voltage battery stack fault monitor that operates without a microprocessor, and without the need for optocouplers or isolators. An LTC6801 can monitor up to 12 series-connected battery cells for overvoltage and undervoltage conditions. Multiple LTC6801 devices can be daisy chained, providing a method to monitor each individual cell in very long battery strings. When connected in a daisy-chain, a single differential clock output confirms that all cells in the stack are within the defined operating range. This clock interface provides high noise immunity and ensures that fault conditions are not hidden by frozen bits or short circuit conditions. The result is a reliable and simple design that can serve as a complete monitoring or redundant circuit. The LTC6801 is a low cost companion to the LTC6802 precision battery measurement and cell balancing IC, providing a backup circuit for hybrid electric battery packs, battery backup systems, and other high powered Li-Ion battery systems.

A wide range of overvoltage and undervoltage thresholds can be set via pin connections and the LTC6801 offers selectable threshold hysteresis and adjustable update rates. The LTC6801 is fully specified for operation from -40°C to 85°C and two temperature sensor inputs are monitored for over-temperature faults.
“The LTC6801 incorporates a number of important reliability features, including a comprehensive self-test to guarantee accuracy,” stated Mike Kultgen, design manager for Linear Technology. “These features will prove invaluable for high reliability battery management systems.”

Samples, demonstration boards and the data sheet for the LTC6801 are now available. Prices start at $US 4.48 each in 1,000-piece quantities. The product will be available in production quantities in the first calendar quarter 2010.