LTC6813 Multi-Cell Battery Monitor

Analog Devices' LTC6813 is a multi-cell battery stack monitor. This device can measure up to 18 series connected battery cells with a total measurement error of less than 2.2 mV. The cell measurement range of 0 V to 5 V makes the LTC6813 suitable for most battery chemistries. All 18 cells can be measured in 290 μs, and lower data acquisition rates can be selected for high noise reduction.

Multiple LTC6813 parts can be connected in series, permitting simultaneous cell monitoring of long, high voltage battery strings. Each device has an isoSPI™ interface for high speed, RF immune, long-distance communications. Multiple devices are connected in a daisy chain with one host processor connection for all devices. This daisy chain can be operated bidirectionally, ensuring communication integrity, even in the event of a fault along the communication path.

The LTC6813 can be powered directly from the battery stack or an isolated supply. This monitor includes passive balancing for each cell, with individual PWM duty cycle control for each cell. Other features include an on-board 5 V regulator, nine general purpose I/O lines and a sleep mode, where current consumption is reduced to 6 μA. The LTC6813 is ideal for electric/hybrid vehicles, battery backup systems, and high-power battery systems.

Features
Measures up to 18 battery cells in a series Stackable architecture supports 100s of cells Built-in isoSPI interface 1 Mb isolated serial communications Uses a single twisted pair, up to 100 meters Low EMI susceptibility and emissions Bidirectional for broken wire protection 290 µs to measure all cells in a system		Synchronized voltage and current measurement 16-bit delta-sigma ADC For ISO 26262-compliant systems 64-lead LQFP package 6 µA sleep mode supply current 9 general purpose digital I/O or analog inputs Passive cell balancing up to 200 mA (max.) with programmable pulse width modulation
Applications
Electric, hybrid vehicles Backup battery systems		Grid energy storage High power portable equipment