Features and Benefits
- 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
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.
- Electric and Hybrid Electric Vehicles
- Backup Battery Systems
- Grid Energy Storage
- High Power Portable Equipment
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
The demonstration circuit DC2792B is an SPI serial to dual-port isoSPI adapter that uses a pair of multiplexed LTC6820 isoSPI transceivers and miniaturized isoSPI connectors (2 contact DuraClik). The board can functionally replace a DC1941 in cases where isoSPI battery-management (BMS) devices are being evaluated, but provides a second isoSPI master to exercise the reversible isoSPI feature where available. The SPI interface can be provided via the legacy 14-contact ribbon cable from either a DC590 or DC2026 USB adapter, or directly installed on the DC2026 as a Linduino shield. The two isoSPI ports are MAIN and AUXiliary, with activity of each indicated by blue LEDs. For use in place of DC1941 or non-reversible isoSPI networks, the MAIN port must be used. Power for the DC2792B comes indirectly from the USB port of the host computer, via the USB to serial adapter being used.
Demonstration circuit 2259A is a Daisy Chain isoSPI Battery-Stack Monitor featuring the LTC6811-1. Multiple boards can be linked through a 2-wire isolated serial interface to monitor any number of cells on a stack.
Tools & Simulations
Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits. Each Linduino-supported product includes an example main program, defined in the LTSketchbook/Part Number folder and driver code, defined in the LTSketchbook/libraries folder.
Press Releases (1)
Technical Articles (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.