LTC6806 36 Channel Fuel Cell Monitor FEATURES DESCRIPTION n 36 Measurement Channels Monitor up to 144 Fuel The LTC 6806 is a fuel cell monitor that measures up to Cells in Series 144 Series Connected Fuel cells with a total measurement n Channel Measurement Range: 5V error of less than 15mV. The LTC6806 includes 36 input n Cell Stack Voltage Range: 80V to 150V channels, each with a 5V measurement range allowing n Operates from a Single 5V Supply each channel to measure from 1 to 4 series-connected n Stackable Architecture Supports Large Fuel Cell Stacks fuel cells. n Built-In isoSPI Interface All 36 inputs can be measured within 6.75ms in fast ADC n 1MB/s Isolated Serial Communications mode. Lower data acquisition rates can be selected for n Uses a Single Twisted Pair, Up to 100 Meters high noise reduction. In the normal ADC mode, all cells n Low EMI Susceptibility and Emissions are measured within 10.3ms, with a total measurement n Bidirectional for Broken Wire Protection error of less than 15mV. n 15mV Total Measurement Error n Each LTC6806 has an isoSPI interface for high speed, RF- 6.75ms to Measure All Cells in a System n immune, long distance communications. Two communica- Delta-Sigma Converter with Built-In Noise Filter n tion modes are available by pin selection: in daisy-chain Six General Purpose Digital I/O or Analog Inputs n mode, multiple devices are connected in a daisy chain with Temperature or Other Sensor Inputs n one host processor connection for all devices in parallel 12A Sleep Mode Supply Current n mode, multiple devices are connected in parallel to the 64-Lead LQFP Package n host processor, with each device individually addressed. AEC-Q100 Qualified for Automotive Applications Multiple LTC6806 devices can be connected in series, permitting simultaneous cell monitoring of very large fuel APPLICATIONS cell stacks. As shown in the typical application, twelve n Fuel Cell Electric and Hybrid Electric Vehicles LTC6806s are connected in series to monitor 432 fuel cells. n Backup Power Systems Alternatively, 432 cells can be monitored using six ICs by n High Power Portable Equipment monitoring groups of two cells, or four ICs by monitoring All registered trademarks and trademarks are the property of their respective owners. Protected groups of three cells. by U.S. patents, including 8908779, 9270133. TYPICAL APPLICATION 432 Fuel Cells Monitored by 4, 6 or 12 LTC6806 ICs LTC6806 LTC6806 LTC6820 P 6806 TA01 Rev 0 1 Document Feedback For more information www.analog.comLTC6806 TABLE OF CONTENTS Features ............................................................................................................................ 1 Applications ....................................................................................................................... 1 Typical Application ............................................................................................................... 1 Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Order Information ................................................................................................................. 3 Pin Configuration ................................................................................................................. 3 Electrical Characteristics ........................................................................................................ 4 Typical Performance Characteristics .........................................................................................10 Pin Functions .....................................................................................................................13 Block Diagram ....................................................................................................................14 Operation..........................................................................................................................15 State Diagram ....................................................................................................................................................... 15 LTC6806 Core State Descriptions ......................................................................................................................... 15 isoSPI State Descriptions ..................................................................................................................................... 16 Sleep Timer ........................................................................................................................................................... 16 Power Consumption ............................................................................................................................................. 16 ADC Operation ...................................................................................................................................................... 17 Continuous Monitoring (MONITOR State) ............................................................................................................ 22 Data Acquisition System Diagnostics ................................................................................................................... 24 Serial Interface Overview ...................................................................................................................................... 28 4-Wire Serial Peripheral Interface (SPI) Physical Layer ........................................................................................ 29 2-Wire Isolated Interface (iso SPI) Physical Layer ................................................................................................. 30 Data Link Layer ..................................................................................................................................................... 38 Network Layer ....................................................................................................................................................... 39 Programming Examples ....................................................................................................................................... 53 Applications Information .......................................................................................................55 Providing DC Power .............................................................................................................................................. 55 Digital Communications ........................................................................................................................................ 56 Configuring isoSPI Hardware ................................................................................................................................ 58 Filtering of Cell and GPIO Inputs ........................................................................................................................... 68 Enhanced Applications .......................................................................................................................................... 70 Package Description ............................................................................................................73 Typical Application ..............................................................................................................74 Related Parts .....................................................................................................................74 Rev 0 2 For more information www.analog.com