LTC6803-2_15 Datasheet, PDF (1/40 Pages) Linear Technology – Multicell Battery Stack Monitor

FEATURES
n _{Measures Up to 12 Battery Cells in Series}
n _{Stackable Architecture}
n _{Supports Multiple Battery Chemistries}
and Supercapacitors
n _{Individually Addressable Serial Interface}
n _{0.25% Maximum Total Measurement Error}
n _{Engineered for ISO26262 Compliant Systems}
n _{13ms to Measure All Cells in a System}
n _{Passive Cell Balancing:}
– Integrated Cell Balancing MOSFETs
– Ability to Drive External Balancing MOSFETs
n _{Onboard Temperature Sensor and Thermistor Inputs}
n _{1MHz Serial Interface with Packet Error Checking}
n _{Safe with Random Connection of Cells}
n _{Built-In Self Tests}
n _{Delta-Sigma Converter With Built-In Noise Filter}
n _{Open-Wire Connection Fault Detection}
n _{12µA Standby Mode Supply Current}
n _{High EMI Immunity}
n _{44-Lead SSOP Package}
APPLICATIONS
n _{Electric and Hybrid Electric Vehicles}
n _{High Power Portable Equipment}
n _{Backup Battery Systems}
n _{Electric Bicycles, Motorcycles, Scooters}
LTC6803-2/LTC6803-4
Multicell Battery Stack
DESCRIPTION
Monitor
The LTC^®6803 is a 2nd generation, complete battery moni-
toring IC that includes a 12-bit ADC, a precision voltage
reference, a high voltage input multiplexer and a serial
interface. Each LTC6803 can measure up to 12 series
connected battery cells or supercapacitors. Many LTC6803
devices can be stacked to measure the voltage of each cell
in a long battery string. Each LTC6803-2/LTC6803-4 has
an individually addressable serial interface, allowing up
to 16 LTC6803-2/LTC6803-4 devices to interface to one
control processor and operate simultaneously. Each cell
input has an associated MOSFET switch for discharging
overcharged cells. The LTC6803-2 connects the bottom
of the stack to V^– internally. It is pin compatible with the
LTC6802-2, providing a drop-in upgrade. The LTC6803-4
separates the bottom of the stack from V^–, improving
cell 1 measurement accuracy.
The LTC6803 provides a standby mode to reduce supply
current to 12µA. Furthermore, the LTC6803 can be powered
from an isolated supply, providing a technique to reduce
battery stack current draw to zero.
The related LTC6803-1 and LTC6803-3 offer a serial in-
terface that allows the serial ports of multiple LTC6803-1
or LTC6803-3 devices to be daisy chained without opto-
couplers or isolators.
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
+
12-CELL
BATTERY OR ₊
CAPACITOR
STRING
+
NEXT 12-CELL
PACK BELOW
V⁺
LTC6803-4
DIE TEMP
REGISTERS
AND
MUX
CONTROL
12-BIT
∆Σ ADC
SERIAL
DATA
4-BIT
ADDRESS _50V
ISOLATED 12V
DC/DC
CONVERTER
V^–
100k NTC
VOLTAGE
REFERENCE
EXTERNAL
TEMP
100k
680324 TA01a
Supply Current vs Modes of Operation
1mA
100µA
10µA
1µA
100nA
10nA
1nA
HW
SHUTDOWN
STANDBY
MEASURE
680324 TA01b
680324fa
1