12-Channel Multicell Battery Monitor

Data Sheet

ADBMS6815

Rev. SpA

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FEATURES

Measures up to 12 battery cells in series

Maximum lifetime total measurement error: 1.5 mV

Stackable architecture for high voltage battery packs

Built-in isoSPI interface

2 Mb isolated serial communications

Uses a single twisted pair, up to 20 meters

Low EMI susceptibility and emissions

Bidirectional for broken wire protection

Capacitor or transformer coupled

Hot plug tolerant without external protection

ADBMS6815WFS models designed for use in ISO 26262

applications for Automotive Safety Integrity Level

Capability D (ASIL D)

Diagnostics for IC and application circuit failure modes

304 μs to measure all cells in a system

16-bit ADC with programmable noise filter

Passive cell balancing up to 300 mA per channel with

programmable PWM

7 GPIO or analog inputs

Temperature or other sensor inputs

Sleep state supply current: 5.5 μA

48-lead LQFP package with exposed pad

AEC-Q100 qualified for automotive applications

APPLICATIONS

Electric and hybrid electric vehicles

Backup battery systems

Grid energy storage

Large portable power banks

TYPICAL APPLICATION CIRCUIT

LTC2949

BATTERY

PACK

MONITOR

isoSPI

PORT

LTC6820

isoSPI

SPI

SPI

LTC6820

isoSPI

BMS CONTROLLER

(SAFETY MICROCONTROLLER)

isoSPI

PORT B

isoSPI

PORT A

isoSPI

PORT B

isoSPI

PORT A

isoSPI

PORT A

isoSPI

PORT B

isoSPI

PORT A

isoSPI

PORT B

UP TO

12

CELLS

+

OPTIONAL

REVERSIBLE

isoSPI

LOOP

4

4

HV–

ADBMS6815

ADBMS6815

ADBMS6815

ADBMS6815

–t°

MODULE 2

MODULE N – 1

MODULE 1

MODULE N

4 MODULES SHOWN

UP TO

12

CELLS

UP TO

12

CELLS

–t°

+

UP TO

12

CELLS

+

–t°

HV+

–t°

+

BAT+

CHASSIS

GND

Figure 1. Typical Application Circuit

GENERAL DESCRIPTION

The ADBMS6815 is a multicell battery stack monitor that

measures up to 12 series connected battery cells with a lifetime

total measurement error (TME) of less than 1.5 mV. The cell

measurement range of 0 V to 5 V makes the ADBMS6815

suitable for most battery chemistries. All 12 cells can be measured

in 304 μs, and lower data acquisition rates can be selected for

high noise reduction.

Multiple ADBMS6815 devices can be connected in series,

permitting simultaneous cell monitoring of long, high voltage

battery strings. Each ADBMS6815 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 ADBMS6815 can be powered directly from the battery

stack or from an isolated supply. The ADBMS6815 includes

passive balancing for each cell, with individual pulse-width

modulation (PWM) duty cycle control for each cell. Other

features include an on-board 5 V regulator, seven general-

purpose input/output (GPIO) lines, and a sleep state, where

current consumption is reduced to 5.5 μA.

The ADBMS6815WFS models are designed for use in

ISO 26262 applications for Automotive Safety Integrity Level

Capability D (ASIL D).

For more information on the ADBMS6815, visit the ADBMS6815 product page.