12 Channel Multicell Battery Monitor with Addressable Interface, Generation 2

The LTC6803 is a 2nd generation, complete battery monitoring IC that includes a 12-bit ADC, a precision voltage reference, a high voltage input multiplexer and a serial interface. Each LTC6803 can measure up to 12 series connected battery cells or supercapacitors. Many LTC6803 devices can be stacked to measure the voltage of each cell in a long battery string. Each LTC6803-2/LTC6803-4 has an individually addressable serial interface, allowing up to 16 LTC6803-2/LTC6803-4 devices to interface to one control processor and operate simultaneously. Each cell input has an associated MOSFET switch for discharging overcharged cells. The LTC6803-2 connects the bottom of the stack to V– internally. It is pin compatible with the LTC6802-2, providing a drop-in upgrade. The LTC6803-4 separates the bottom of the stack from V–, improving cell 1 measurement accuracy.

The LTC6803 provides a standby mode to reduce supply current to 12μA. Furthermore, the LTC6803 can be powered from an isolated supply, providing a technique to reduce battery stack current draw to zero.

The related LTC6803-1 and LTC6803-3 offer a serial interface that allows the serial ports of multiple LTC6803-1 or LTC6803-3 devices to be daisy chained without optocouplers or isolators.

SPI Interface

Isolated V–

LTC6802 Pin Compatible

LTC6803-1

Daisy Chain

No

Yes

LTC6803-2

Addressable

No

Yes

LTC6803-3

Daisy Chain

Yes

No

LTC6803-4

Addressable

Yes

No

Applications

* Electric and Hybrid Electric Vehicles

* High Power Portable Equipment

* Backup Battery Systems

* Electric Bicycles, Motorcycles, Scooters

* Measures Up to 12 Battery Cells in Series

* Stackable Architecture

* Supports Multiple Battery Chemistries and Supercapacitors

* Individually Addressable Serial Interface

* 0.25% Maximum Total Measurement Error

* Engineered for ISO26262 Compliant Systems

* 13ms to Measure All Cells in a System

* Passive Cell Balancing:

* Integrated Cell Balancing MOSFETs

* Ability to Drive External Balancing MOSFETs