Automotive battery stack monitor achieves 0.04% measurement accuracy

Linear Technology has released the LTC6811 high voltage battery stack monitor, a drop-in replacement for the LTC6804, and claimed to feature higher performance and 25% lower price.

The LTC6811 is a complete battery measuring IC for hybrid/electric vehicles that incorporates a deep buried Zener voltage reference, high voltage multiplexers, 16-bit delta-sigma ADCs and a 1Mbps isolated serial interface.An LTC6811 is said to measure up to 12 series-connected battery cell voltages with better than 0.04% accuracy.In the fastest ADC mode, it is claimed that all cells can be measured within 290µsec.

For large battery packs, multiple LTC6811s can be interconnected and operated simultaneously, using Linear’s 2-wire isoSPI interface.This built-in interface is said to provide electrically isolated, high RF noise immune communication for data rates up to 1Mbit/ps.Using twisted pair, many LTC6811s can be connected in a daisy chain to one host processor, said to enable the measurement of hundreds of cells in high voltage battery stacks.

The LTC6811 is available in an 8 x 12mm surface mount SSOP package and operates across a temperature range from -40 to 125°C.