The LTC6811 is a multicell battery stack monitor that measures up to 12 series connected battery cells with a total measurement error of less than 1.2mV. The cell measurement range of 0V to 5V makes the LTC6811 suitable for most battery chemistries. All 12 cells can be measured in 290µs, and lower data acquisition rates can be selected for high noise reduction.
Multiple LTC6811 devices can be connected in series, permitting simultaneous cell monitoring of long, high voltage battery strings. Each LTC6811 has an isoSPI interface for high speed, RF-immune, long distance communications. Using the LTC6811-1, multiple devices are connected in a daisy chain with one host processor connection for all devices. Using the LTC6811-2, multiple devices are connected in parallel to the host processor, with each device individually addressed.
The LTC6811 can be powered directly from the battery stack or from an isolated supply. The LTC6811 includes passive balancing for each cell, with individual PWM duty cycle control for each cell. Other features include an onboard 5V regulator, five general purpose I/O lines and a sleep mode, where current consumption is reduced to 4µA.
Feature
Pin-Compatible Upgrade from the LTC6804
Measures Up to 12 Battery Cells in Series
1.2mV Maximum Total Measurement Error
Stackable Architecture for High Voltage Systems
Built-in isoSPI™ Interface
1Mb Isolated Serial Communications
Uses a Single Twisted Pair, up to 100 Meters
Low EMI Susceptibility and Emissions
290µs to Measure All Cells in a System
Synchronized Voltage and Current Measurement
16-Bit ADC with Programmable Noise Filter
Engineered for ISO 26262-Compliant Systems
Passive Cell Balancing with Programmable Timer
5 General Purpose Digital I/O or Analog Inputs
Temperature or other Sensor Inputs
Configurable as an I2C or SPI master
4μA Sleep Mode Supply Current
48-Lead SSOP Package
AEC-Q100 Qualified for Automotive Applications
Applications
Catalogue
FPGA / CPLD
Memory
MOS 
MCU 
DSP
OCEP
Secondary 
Other 
