AD8280 Datasheet, PDF (1/24 Pages) Analog Devices – Lithium Ion Battery Safety Monitor

Lithium Ion Battery Safety Monitor
AD8280
FEATURES
GENERAL DESCRIPTION
Wide supply voltage range: 6.0 V to 30.0 V
Multiple inputs can monitor 3 to 6 cell voltages
and 2 temperatures
Adjustable threshold levels: overvoltage, undervoltage,
overtemperature
Alarm options: separate or shared alarms
Extended temperature range performance
−40°C ≤ TA ≤ +105°C
Can be daisy-chained
Internal reference
Powered from battery stack
LDO available to power isolator
Qualified for automotive applications
Extensive self-test feature aids in meeting ASIL/SIL
requirements
APPLICATIONS
Lithium ion battery backup monitor and threshold detection
Electric and hybrid electric vehicle
Industrial vehicle
Uninterruptible power supply
Wind and solar
The AD8280 is a hardware-only safety monitor for lithium ion
battery stacks. The part has inputs to monitor six battery cells
and two temperature sensors (either NTC or PTC thermistors).
The part is designed to be daisy-chained with other AD8280
devices to monitor a stack of significantly more than six cells
without the need for numerous isolators. Its output can be con-
figured for an independent or shared alarm state.
The AD8280 functions independently from a primary monitor
and contains its own reference and LDO, both of which are
powered completely from the battery cell stack. The reference, in
conjunction with external resistor dividers, is used to establish
trip points for the overvoltages and undervoltages. Each cell
channel contains programmable deglitching circuitry to prevent
alarms from transient input levels.
The AD8280 also has two digital pins that can be used to select
various combinations of inputs in the case where fewer than six
cells are to be monitored. Most important, it has a self-test feature,
making it suitable for high reliability applications, such as auto-
motive hybrid electric vehicles or higher voltage industrial usage,
such as uninterruptible power supplies. The AD8280 can function
over a temperature range of −40°C to +105°C.
FUNCTIONAL BLOCK DIAGRAM
OT
VTOP LDO
LDOS REF FB
AIINOV AIINUV AIINOT ENBO
UV OV
TESTO
VTOPS
VBOT2
VBOT2S
VBOT1
VBOT1S
VIN6
VIN5
VIN4
VIN3
LDO
LEVEL
SHIFTER
REF
C6O
DE-
GLITCHING
C6U
DE-
GLITCHING
I/V
CONVERTER
LEVEL
SHIFTER
DGT0
DGT1
DGT2
GND2
SELF-
TEST
GENERATOR
GND1
VCC
VCCS
TOP
BOT
VIN2
VIN1
VIN0
LEVEL
SHIFTER
VT1
VT2
AD8280
C1O
DE-
GLITCHING
C1U
DE-
GLITCHING
CT1
DE-
GLITCHING
DE-
CT2 _GLITCHING
ALARM
LOGIC
V/I
CONVERTER
SEL0
SEL 1
AVOUTOV
AVOUTUV
AVOUTOT
NPTC
ALRMSEL
OT
AIOUTOV
AIOUTUV AIOUTOT
ENBI TESTI
OT
Figure 1.
Rev. C
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