LTC6802-1 Datasheet

• Qualified for Automotive Applications
• Measures Up to 12 Li-Ion Cells in Series (60V Max)
• Stackable Architecture Enables >1000V Systems
• 0.25% Maximum Total Measurement Error
• 13ms to Measure All Cells in a System
• Cell Balancing:
  • On-Chip Passive Cell Balancing Switches
  • Provision for Off-Chip Passive Balancing
• Two Thermistor Inputs Plus On-Board Temperature Sensor
• 1MHz Daisy-Chainable Serial Interface
• High EMI Immunity
• Delta Sigma Converter with Built-In Noise Filter
• Open Wire Connection Fault Detection
• Low Power Modes
• 44-Lead SSOP Package

• Electric and Hybrid Electric Vehicles
• High Power Portable Equipment
• Backup Battery Systems
• High Voltage Data Acquisition Systems

The LTC6802-1 is a complete battery monitoring IC that includes a 12-bit ADC, a precision voltage reference, a high voltage input multiplexer and a serial interface. Each LTC6802-1 can measure up to 12 series connected battery cells with an input common mode voltage up to 60V. In addition, multiple LTC6802-1 devices can be placed in series to monitor the voltage of each cell in a long battery string. The unique level-shifting serial interface allows the serial ports of these devices to be daisy-chained without optocouplers or isolators.

When multiple LTC6802-1 devices are connected in series they can operate simultaneously, permitting all cell voltages in the stack to be measured within 13ms.

To minimize power, the LTC6802-1 offers a measure mode, which simply monitors each cell for overvoltage and undervoltage conditions. A standby mode is also provided.

Each cell input has an associated MOSFET switch for discharging overcharged cells.

For large battery stack applications requiring individually addressable serial communications, see the LTC6802-2.