LTC6803-3_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 _{Serial Interface Daisy Chains to Adjacent Devices}
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}
LTC6803-1/LTC6803-3
Multicell Battery Stack
Monitor
DESCRIPTION
The LTC^®6803 is a 2nd generation, complete battery
monitoring 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. Using a
unique level shifting serial interface, multiple LTC6803-1/
LTC6803-3 devices can be connected in series, without
opto-couplers or isolators, allowing for monitoring of every
cell in a long string of series-connected batteries. Each cell
input has an associated MOSFET switch for discharging
overcharged cells. The LTC6803-1 connects the bottom
of the stack to V^– internally. It is pin compatible with the
LTC6802‑1, providing a drop-in upgrade. The LTC6803-3
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.
For applications requiring individually addressable serial
communications, see the LTC6803-2/LTC6803-4.
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
+
+
NEXT 12-CELL
PACK BELOW
V⁺
LTC6803-3
SERIAL DATA
TO LTC6803-3
DIE TEMP
ABOVE
REGISTERS
AND
MUX
CONTROL
12-BIT
∆Σ ADC
50V
ISOLATED
12V
DC/DC
CONVERTER
V^–
100k NTC
VOLTAGE
REFERENCE
EXTERNAL
TEMP
100k
SERIAL DATA
TO LTC6803-3
BELOW
680313 TA01a
Supply Current vs Modes of Operation
1mA
100µA
10µA
1µA
100nA
10nA
1nA
HW
SHUTDOWN
STANDBY
MEASURE
680313 TA01b
680313fa
1