GENERAL DESCRIPTION

The ADBMS68211 (single) and ADBMS68221 (dual) provide bidirectional

isolated serial port interface (isoSPI?) communications

between two isolated devices through a single twisted pair connection

for each data link. Each transceiver encodes logic states into

signals that are transmitted across an isolation barrier to another

transceiver. The receiving device decodes the transmission and

drives the slave bus to the appropriate logic states. The isolation

barrier can be bridged by capacitors or by a pulse transformer to

achieve hundreds of volts of isolation.

The ADBMS6821/ADBMS6822 transceivers drive differential signals

using matched source and sink currents, eliminating the requirement

for a transformer center tap and reducing electromagnetic

interference (EMI). Precision window comparators in the receiver

detect the differential signals.

The transceivers can be paired with advanced Analog Devices,

Inc., battery stack monitors to enable cell voltage and sensor monitoring

even while the system controller is powered down (low power

cell monitoring, or LPCM). The transceivers provide a timeout

function that wake up or alert the system when a pass heartbeat

message has not been received in the programmed time period.

Throughout this data sheet, all pin names refer to both transceivers

on the ADBMS6822. For example, VDD refers to both VDD and VDD2.

FEATURES

? Up to 2 Mbps isolated bidirectional serial data communications

? Drop in compatible: single (ADBMS6821) and dual

(ADBMS6822)

? Fully independent dual transceivers (ADBMS6822)

? Simple galvanic isolation using capacitors or transformers

? Bidirectional interface over a single twisted pair

? Supports cable lengths up to 100 meters

? Very low EMI susceptibility and emissions

? LPCM support for Analog Devices battery monitors

? Interrupt output for LPCM system wake-up

? 4 Mbps unidirectional mode

? Requires no software changes in most SPI systems

? Ultralow idle current

? Automatic interface wake-up detection

? Operating temperature range: –40°C to +125°C

? 3.0 V to 5.5 V isoSPI driver power supply

? 1.7 V to 5.5 V interface to microcontrollers

? 3.0 V to 30 V input for powering wake-up and monitoring functions

(12 V battery compatible)

? 32-lead, side solderable LFCSP

? AEC-Q100 qualified for automotive applications

APPLICATIONS

? Electric and hybrid electric vehicles

? Backup battery systems

? Industrial networking

? Remote sensors