DC2732A-C Analog Devices

LTC2949 Current, Voltage, and Charge Monitor for High Voltage Battery Packs FEATURES DESCRIPTION n Measures Battery Stack Voltage, Current and Power The LTC 2949 is a high precision current, voltage, tem- n Indicates Accumulated Battery Charge and Energy perature, charge and energy meter for electrical and hybrid n 20-Bit Current Measurement with <1V Offset vehicles and other isolated current sense applications. It n Built-In Isolated isoSPI or SPI Interface infers charge and energy flowing in and out of the battery n LTC68xx/ADBMS68xx Compatible, Supports pack by monitoring simultaneously the voltage drop over Synchronous Measurements with Cell Monitors up to two sense resistors and the battery pack voltage. n Up to 12 Buffered Voltage Measurement Inputs Low offset ADCs ensure accurate measurement of n Up to 5 GPIOs, Configurable to Drive Ground, Supply voltage and current with insignificant power loss. Con- or Toggling at 400kHz tinuous integration of current and power ensures lossless n High or Low Side Current Sense tracking of charge and energy delivered or received by n 0.3% Current and Voltage Accuracy the battery pack. n 1% Energy and Charge Accuracy n True Average ADCs The built-in serial interface can be configured to support 2 n I C EEPROM Interface to Store Board Calibration Factors isolated isoSPI communication to the host or as SPI n Threshold Registers for all Measured Quantities interface. n Engineered for ISO26262 Compliant Systems The LTC2949 features 12 internally buffered high imped- n Open Wire Detection on Input Pins ance inputs (V1 to V12) for measuring voltages from n Available in 48-Lead LQFP Package external sensors or resistor dividers allowing to measure n AEC-Q100 Qualified for Automotive Applications temperatures, HV-Link voltages, chassis isolation and supervise contactor states. LTC2949 has up to five pro- APPLICATIONS grammable digital outputs which can be set to ground, n Electric and Hybrid Vehicles supply or toggling at 400kHz. n Isolated Current Sensing Programmable threshold and tracking registers reduce n Backup Battery Systems digital traffic to the host. n High Power Portable Equipment All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION Electric Vehicle Battery Meter + + HV 800V HV BAT LINK isoSPI B 3.3M ISOLATION AVCC RESISTANCE 6.5M DVCC LT830x LTC2949 1F 3.3M LINK VOLTAGE V5 GND isoSPI A 6.5M 30k 22k V4 6.5M GPIO1 CELL VREF V1 MONITORS BATP 100k 22k POWER STACK 30k 30k isoSPI B ENERGY VOLTAGE V3 LINK VOLTAGE BATM V2 MASTER LTC6820 CURRENT TEMPERATURE SPI SPI isoSPI 6.5M CHARGE isoSPI I1P I1M GND GND 100k isoSPI A I2P I2M ISOLATED COMMUNICA TION 50 HV LINK HV 2949 TA01 BAT Rev A 1 Document Feedback For more information www.analog.com LTC681x LTC681x CHASSIS-GND STD4NK100ZLTC2949 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 .....................................................................................................................11 Pin Functions .....................................................................................................................12 Block Diagram ....................................................................................................................13 Operation..........................................................................................................................14 Overview ............................................................................................................................................................... 14 Modes of Operation .............................................................................................................................................. 15 Data Acquisition Channels .................................................................................................................................... 16 Power Measurement ............................................................................................................................................. 19 Charge, Energy and Time ...................................................................................................................................... 20 Overcurrent Comparators ..................................................................................................................................... 21 SERIAL INTERFACES ............................................................................................................22 Serial Interfaces Overview .................................................................................................................................... 22 4-Wire Serial Peripheral Interface (SPI) Physical Layer ........................................................................................ 22 2-Wire Isolated Interface (isoSPI) Physical Layer ................................................................................................. 23 Data Link Layer ..................................................................................................................................................... 28 Network Layer ....................................................................................................................................................... 28 REGISTER MAP ...................................................................................................................41 REGISTER Description ..........................................................................................................42 MEMORY MAP AND Paging Mechanism............................................................................................................... 42 Register Map PAGE0 ............................................................................................................................................. 44 Register Map PAGE1 ............................................................................................................................................ 62 Application Information .........................................................................................................68 Temperature Measurement .................................................................................................................................. 68 Sense Resistor Temperature Compensation ......................................................................................................... 69 Current and Voltage Input Filtering ....................................................................................................................... 74 Powering the LTC2949 ......................................................................................................................................... 75 Package Description ............................................................................................................78 Revision History .................................................................................................................79 Typical Application ..............................................................................................................80 Related Parts .....................................................................................................................80 Rev A 2 For more information www.analog.com