LTC6802-1
Multicell
Battery Stack Monitor
FEATURES
DESCRIPTION
n
The LTC®6802-1 is a complete battery monitoring IC that
includes a 12-bit ADC, a precision voltage reference, a
high voltage input multiplexer and a serial interface. Each
LTC6802-1 can measure up to 12 series connected battery cells with an input common mode voltage up to 60V.
In addition, multiple LTC6802-1 devices can be placed in
series to monitor the voltage of each cell in a long battery
string. The unique level-shifting serial interface allows the
serial ports of these devices to be daisy-chained without
optocouplers or isolators.
n
n
n
n
n
n
n
n
n
n
n
Measures up to 12 Li-Ion Cells in Series (60V Max)
Stackable Architecture Enables >1000V Systems
0.25% Maximum Total Measurement Error
13ms to Measure All Cells in a System
Cell Balancing:
On-Chip Passive Cell Balancing Switches
Provision for Off-Chip Passive Balancing
Two Thermistor Inputs Plus On-Board
Temperature Sensor
1MHz Daisy-Chainable Serial Interface
High EMI Immunity
Delta Sigma Converter with Built-In Noise Filter
Open Wire Connection Fault Detection
Low Power Modes
44-Lead SSOP Package
APPLICATIONS
n
n
n
n
When multiple LTC6802-1 devices are connected in series
they can operate simultaneously, permitting all cell voltages
in the stack to be measured within 13ms.
To minimize power, the LTC6802-1 offers a measure mode,
which simply monitors each cell for overvoltage and undervoltage conditions. A standby mode is also provided.
Each cell input has an associated MOSFET switch for
discharging overcharged cells.
Electric and Hybrid Electric Vehicles
High Power Portable Equipment
Backup Battery Systems
High Voltage Data Acquisition Systems
For large battery stack applications requiring individually
addressable serial communications, see the LTC6802-2.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
NEXT 12-CELL
PACK ABOVE
Measurement Error Over
Extended Temperature
LTC6802-1 SERIAL DATA
TO LTC6802-1
ABOVE
DIE TEMP
+
V
0.30
0.25
12-CELL
BATTERY
STRING
MEASUREMENT ERROR (%)
REGISTERS
AND
CONTROL
MUX
12-BIT
Δ∑ ADC
7 REPRESENTATIVE
UNITS
0.20
0.15
0.10
0.05
0
–0.05
–0.10
–0.15
–0.20
V–
NEXT 12-CELL
PACK BELOW
EXTERNAL
TEMP
–0.25
VOLTAGE
REFERENCE
SERIAL DATA
TO LTC6802-1
BELOW
68021 TA01a
–0.30
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
125
68021 TA01b
100k
100k NTC
68021fa
1
