LTC6810-1/LTC6810-2 6 Channel Battery Stack Monitors FEATURES DESCRIPTION n AEC-Q100 Qualified for Automotive Applications The LTC 6810 is a multicell battery stack monitor. The n Measures Up to 6 Battery Cells in Series LTC6810 measures up to 6 series-connected battery cells n 1.8mV Maximum Total Measurement Error with a total measurement error of less than 1.8mV. The n Stackable Architecture for High Voltage Systems cell measurement range of 0V to 5V makes the LTC6810 n 290s to Measure All Cells in a System. suitable for most battery chemistries. All 6 cells can be n Built-in isoSPI Interface measured in 290s, and lower data acquisition rates can n 1Mb Isolated Serial Communications be selected for high noise reduction. n Uses Single Twisted Pair, Up to 100 Meters Multiple LTC6810-1 devices can be connected in series, n Low EMI Susceptibility and Emissions permitting simultaneous cell monitoring of long, high n Bidirectional for Broken Wire Protection voltage battery strings. Each LTC6810 has an isoSPI n Guaranteed Performance Down to 5V interface for high speed, RF-immune, long distance com- n Performs Redundant Cell Measurements. munications. Using the LTC6810-1, multiple devices are n Engineered for ISO 26262 Compliant Systems connected in a daisy chain with one host processor con- n Passive Cell Balancing with Programmable PWM nection for all devices. The LTC6810-1 supports bidi- n 4 General Purpose Digital I/O or Analog Inputs rectional operation, allowing communication even with n Temperature or Other Sensor Inputs a broken wire. Using the LTC6810-2, multiple devices 2 n Configurable as an I C or SPI master are connected in parallel to the host processor, with each n 4A Sleep Mode Supply Current device individually addressed. n 44-Lead SSOP Package The LTC6810 can be powered directly from the battery stack or from an isolated supply. The LTC6810 includes APPLICATIONS passive balancing for each cell, with PWM duty cycle control for each cell and the ability to perform redundant n Electric and Hybrid Electric Vehicles cell measurements. Other features include an onboard 5V n Backup Battery Systems regulator, 4 general purpose I/O lines and a sleep mode in n Grid Energy Storage which current consumption is reduced to 4A. n High Power Portable Equipment All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION REVERSIBLE LTC6810 + + Measurement Error vs V SERIAL 2.0 isoSPI PORT B 16-BIT WITH MEASUREMENT ERROR OF LOGIC 1.5 PROGRAMMABLE CELL1 WITH 3.3V INPUT, NOISE FILTER V INTERNALLY GENERATED, REG isoSPI SERIAL 1.0 FIGURE 2 PORT A 4-WIRE 0.5 SPI UNIQUE ID 0 MUX OPTIONAL 0.5 EEPROM DIE TEMP 1.0 CURRENT MUX 125C SENSOR 4 GENERAL PURPOSE 1.5 25C ANALOG IN AND 40C DIGITAL IN/OUT 2.0 SECOND 5 10 15 20 25 30 REFERENCE 10k + V (V) 6810 TA01b NTC FIRST REFERENCE 68101 TA01a Rev. A 1 Document Feedback For more information www.analog.com MEASUREMENT ERROR (mV)LTC6810-1/LTC6810-2 TABLE OF CONTENTS Features ............................................................................................................................ 1 Applications ....................................................................................................................... 1 Typical Application ............................................................................................................... 1 Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Pin Configuration ................................................................................................................. 3 Order Information ................................................................................................................. 4 Electrical Characteristics ........................................................................................................ 4 Typical Performance Characteristics .........................................................................................10 Pin Functions .....................................................................................................................17 Block Diagram ....................................................................................................................18 Operation..........................................................................................................................20 State Diagram ....................................................................................................................................................... 20 Core LTC6810 State Descriptions ......................................................................................................................... 20 isoSPI State Descriptions ..................................................................................................................................... 21 Power Consumption ............................................................................................................................................. 22 V Configurations ............................................................................................................................................. 23 REG ADC Operation ...................................................................................................................................................... 24 Data Acquisition System Diagnostics ................................................................................................................... 29 Watchdog and Discharge Timer ............................................................................................................................ 37 Reset Behaviors .................................................................................................................................................... 39 S Pin Pulse Width Modulation for Cell Balancing .................................................................................................. 40 Discharge Timer Monitor ...................................................................................................................................... 40 2 I C/SPI Master on LTC6810 Using GPIOs............................................................................................................. 40 S Pin Muting ......................................................................................................................................................... 44 Serial ID and Authentication ................................................................................................................................. 45 Serial Interface Overview ...................................................................................................................................... 45 4-Wire Serial Peripheral Interface (SPI) Physical Layer ........................................................................................ 45 Data Link Layer ..................................................................................................................................................... 55 Network Layer ....................................................................................................................................................... 55 Applications Information .......................................................................................................70 Providing DC Power .............................................................................................................................................. 70 Internal Protection and Filtering ............................................................................................................................ 71 Cell Balancing ....................................................................................................................................................... 72 Discharge Control During Cell Measurements ...................................................................................................... 74 Digital Communications ........................................................................................................................................ 76 Enhanced Applications .......................................................................................................................................... 86 Reading External Temperature Probes .................................................................................................................. 86 Package Description ............................................................................................................88 Revision History .................................................................................................................89 Typical Application ..............................................................................................................90 Related Parts .....................................................................................................................90 Rev. A 2 For more information www.analog.com