Document
FEATURES
nn Qualified for Automotive Applications nn Measures Up to 12 Li-Ion Cells in Series (60V Max) nn Stackable Architecture Enables Monitoring High
Voltage Battery Stacks nn Individually Addressable with 4-Bit Address nn 0.25% Maximum Total Measurement Error nn 13ms to Measure All Cells in a System nn Cell Balancing:
nn On-Chip Passive Cell Balancing Switches nn Provision for Off-Chip Passive Balancing nn Two Thermistor Inputs Plus Onboard Temperature Sensor nn 1MHz Serial Interface with Packet Error Checking nn High EMI Immunity nn Delta-Sigma Converter with Built-In Noise Filter nn Open-Wire Connection Fault Detection nn Low Power Modes nn 44-Lead SSOP Package
APPLICATIONS
nn Electric and Hybrid Electric Vehicles nn High Power Portable Equipment nn Backup Battery Systems nn High Voltage Data Acquisition Systems
LTC6802-2 Multicell Addressable Battery Stack Monitor
DESCRIPTION
The LTC®6802-2 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 LTC6802-2 can measure 12 series connected battery cells, with a total input voltage up to 60V. The voltage on all 12 input channels can be measured within 13ms. Many LTC6802-2 devices can be stacked to measure the voltage of each cell in a long battery string. Each LTC6802-2 has an individually addressable serial interface, allowing up to 16 LTC6802-2 devices to interface to one control processor and operate simultaneously. To minimize power, the LTC6802-2 offers a measure mode to monitor each cell for overvoltage and undervoltage conditions. A standby mode is also provided to reduce supply current to 50µA. Each cell input has an associated MOSFET switch that can discharge any overcharged cell. The related LTC6802-1 offers a serial interface that allows the serial ports of multiple LTC6802-1 devices to be daisy chained without opto-couplers or isolators.
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TYPICAL APPLICATION
NEXT 12-CELL PACK ABOVE
+
12-CELL BATTERY STRING
+
+
NEXT 12-CELL PACK BELOW
V+ LTC6802-2 DIE TEMP
REGISTERS AND
CONTROL MUX
SERIAL DATA 4-BIT ADDRESS
V– 100k NTC
12-BIT ∆∑ ADC
EXTERNAL TEMP
VOLTAGE REFERENCE
68022 TA01a
100k
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MEASUREMENT ERROR (%)
Measurement Error Over Extended Temperature
0.30 0.25
7 REPRESENTATIVE UNITS VS = 43.2V
0.20 CELL VOLTAGE 3.6V
0.15
0.10
0.05
0
–0.05
–0.10
–0.15
–0.20
–0.25
–0.30 –50 –25
0 25 50 75 TEMPERATURE (°C)
100 125
68022 TA01b
Rev. B
1
LTC6802-2
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Total Supply Voltage (V+ to V–)..................................60V Input Voltage (Relative to V–)
C1............................................................. –0.3V to 9V C12........................................... V+ – 0.6V to V+ + 0.3V Cn (Note 5).......................... –0.3V to Min (9 • n, 60V) Sn (Note 5).......................... –0.3V to Min (9 • n, 60V) All Other Pins............................................ –0.3V to 7V Voltage Between Inputs Cn to Cn – 1.............................................. –0.3V to 9V Sn to Cn – 1.............................................. –0.3V to 9V C12 to C8................................................ –0.3V to 25V C8 to C4.................................................. –0.3V to 25V C4 to V–.................................................. –0.3V to 25V Operating Temperature Range..................–40°C to 85°C Specified Temperature Range...................–40°C to 85°C Junction Temperature............................................ 150°C Storage Temperature Range................... –65°C to 150°C *n = 1 to 12
PIN CONFIGURATION
V+ 1 C12 2 S12 3 C11 4 S11 5 C10 6 S10 7 C9 8 S9 9 C8 10 S8 11 C7 12 S7 13 C6 14 S6 15 C5 16 S5 17 C4 18 S4 19 C3 20 S3 21 C2 22
TOP VIEW
44 CSBI 43 SDO 42 SDI 41 SCKI 40 A3 39 A2 38 A1 37 A0 36 GPIO2 35 GPIO1 34 WDTB 33 MMB 32 TOS 31 VREG 30 VREF 29 VTEMP2 28 VTEMP1 27 NC 26 V– 25 S1 24 C1 23 S2
G PACKAGE 44-LEAD PLASTIC SSOP TJMAX = 150°C, θJA = 70°C/W
ORDER INFORMATION
TUBE
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION SPECIFID TEMPERATURE RANGE
LTC6802IG-2#PBF
LTC6802IG-2#TRPBF
LTC6802G-2
44-Lead Plastic SSOP
–40°C to 85°C
LTC6802IG-2#3ZZPBF
LTC6802IG-2#3ZZTRPBF LTC6802G-2
44-Lead Plastic SSOP
–40°C to 85°C
Contact the factory for parts specified with wider operating temperature ranges.
Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
Versions of the LTC6802-2 models are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. These models are available with #WTRPBF, #WPBF or #ZZPBF suffix and are listed in ADI’s ARPL.
Note that these automotive models may hav.