12 Channel Multicell Battery Monitor with Addressable Interface, Generaion 1

The LTC6802-2 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 LTC6802-2 can measure 12 series connected battery cells, with a total input voltage up to 60V. The voltage on all 12 input channels can be measured within 13ms.

Many LTC6802-2 devices can be stacked to measure the voltage of each cell in a long battery string. Each LTC6802-2 has an individually addressable serial interface, allowing up to 16 LTC6802-2 devices to interface to one control processor and operate simultaneously.

To minimize power, the LTC6802-2 offers a measure mode to monitor each cell for overvoltage and undervoltage conditions. A standby mode is also provided to reduce supply current to 50µA.

Each cell input has an associated MOSFET switch that can discharge any overcharged cell.

The related LTC6802-1 offers a serial interface that allows the serial ports of multiple LTC6802-1 devices to be daisy chained without opto-couplers or isolators.

SPI Interface

Features

LTC6802-1

Daisy Chain

Multiple devices can be connected in serial fashion without digital isolation.

LTC6802-2

Addressable

Parallel addressed SPI interface - each device in a chain communicates with a control processor in parallel via external digital isolators.

Applications

* Electric and Hybrid Electric Vehicles

* High Power Portable Equipment

* Backup Battery Systems

* High Voltage Data Acquisition Systems

* Qualified for Automotive Applications

* Measures Up to 12 Li-Ion Cells in Series (60V Max)

* Stackable Architecture Enables Monitoring High Voltage Battery Stacks

* Individually Addressable with 4-Bit Address

* 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