Datasheet LT8491 (Analog Devices)

LT8491 High Voltage Buck-Boost Battery Charge Controller with Maximum Power Point Tracking (MPPT) and I2C
FEATURES DESCRIPTION
n
VIN Range: 6V to 80V
The LT®8491 is a buck-boost switching regulator battery n
VBAT Range: 1.3V to 80V
charger that implements a constant-current constant- n
Single Inductor Allows VIN Above, Below, or Equal
voltage (CCCV) charging profile used for most battery
to VBAT
types, including sealed lead-acid (SLA), flooded, gel and n
Automatic MPPT for Solar Powered Charging
lithium-ion. n
Automatic Temperature Compensation
The device operates from input voltages above, below or n
I2C Telemetry and Configuration
equal to the output voltage and can be powered by a solar n
Internal EEPROM for Configuration Storage
panel or a DC power supply. On-chip logic provides auto- n
Operation from Solar Panel or DC Supply
matic maximum power point tracking (MPPT) for solar n
Four Integrated Feedback Loops
powered applications. The LT8491 can perform automatic n Synchronizable Fixed Frequency: 100kHz to 400kHz temperature compensation by sensing an external therm- n 64-Lead (7mm × 11mm × 0.75mm) QFN Package istor thermally coupled to the battery. The STATUS pin can be used to drive an LED indicator lamp. The device is
APPLICATIONS
available in a low profile (0.75mm) 7mm × 11mm 64-lead n QFN package. Solar Powered Battery Chargers n Multiple Types of Lead-Acid Battery Charging All registered trademarks and trademarks are the property of their respective owners. n Li-Ion Battery Charger n Battery Equipped Industrial or Portable Military Equipment
TYPICAL APPLICATION Simplified Solar Powered Battery Charger Schematic Maximum Power
GATEVCC´ GATEVCC´
Point Tracking
SOLAR PANEL FULL PANEL SCAN LOAD V TG1 BOOST1 SW1 BG1 CSP CSN BG2 SW2 BOOST2 TG2 PANEL VBAT 6V/DIV CSNIN CSPOUT CSPIN PERTURB CSNOUT + – PERTURB AND AND VIN EXTVCC RECHARGABLE OBSERVE OBSERVE
I2C INTERFACE
LT8491 BATTERY IMON_IN TELEMETRY SDA AV 0.2V/DIV DD STATUS CONTROL SCL CONFIGURATION 8491 TA01b 0.5s/DIV GATEV GATEV CC´ CC THERMISTOR TEMPSENSE INTVCC STATUS CA GND AVDD AVDD 8491 TA01a Rev. 0 Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Overview I2C Serial Interface I2C: START and STOP Conditions I2C: ACKnowledge I2C: Chip Addressing I2C: Clock Stretching I2C: Data Transfer Transactions I2C: Powering the Interface I2C Data Data: Memory Regions Data: Bytes, Words and Long Words Data: Min/Max Register Values Data: Access Permissions Startup Sequence Battery Charging Algorithm Stage 0: Trickle Charging Stage 1: Full Constant Current Stage 2: Constant Voltage Stage 3: (Optional) Reduced Constant Voltage Done Charging Charging Faults Maximum Power Point Tracking Telemetry Operation Telemetry: Configuration Settings Telemetry: Acquisition CRC Operation EEPROM Operation EEPROM: Startup EEPROM: Reading EEPROM: Writing I2C Register Map I2C Register Descriptions Telemetry Registers TELE_TBAT TELE_POUT TELE_PIN TELE_EFF TELE_IOUT TELE_IIN TELE_VBAT TELE_VIN TELE_VINR Status Registers STAT_CHARGER STAT_SYSTEM STAT_SUPPLY STAT_TSx_REMAIN STAT_CHRG_FAULTS STAT_VERSION STAT_BOOT_CRC STAT_CFG_CRC Control The EEPROM CTRL_WRT_TO_BOOT CTRL_EE_WRT_EN Control Other Functions CTRL_HALT_STARTUP CTRL_CHRG_EN CTRL_RESTART_CHIP CTRL_RESET_FLAG CTRL_UPDATE_TELEM Configure The Telemetry CFG_RSENSE1 CFG_RIMON_OUT CFG_RSENSE2 CFG_RDACO CFG_RFBOUT1 CFG_RFBOUT2 CFG_RDACI CFG_RFBIN2 CFG_RFBIN1 Configure Initial Charger Enable CFG_INIT_CHRG_EN Configure VBAT for Stages 0, 1 and 3 CFG_VS3_25C CFG_UV_S0 CFG_S0_UV CFG_S0_S1 CFG_S1_S0 Configure Temperature Fault Limits CFG_TBAT_MIN CFG_TBAT_MAX Configure Stage Timeout Limits CFG_TMR_S0 CFG_TMR_S1 CFG_TMR_S2 CFG_TMR_S3 Configure Automatic Restart CFG_RSTRT_IN_FLT CFG_RSTRT_IN_DONEA CFG_RSTRT_IN_DONEB CFG_RSTRT_IN_S3 Configure Charge Termination CFG_TERMINATE Configure Misc. CFG_SCAN_RATE_LP CFG_SCAN_RATE CFG_CHRG_MISC Configure Temperature Compensation CFG_TC3, CFG_TC2, CFG_TC1 Configure User Code CFG_USER_CODE Manufacturer Data MFR_DATA1 MFR_DATA2 MFR_DATA3 Applications Information Hardware Configuration HW Config: Input Voltage Sensing and Modulation HW Config: VINR Pin Connections HW Config: Solar Panel Powered Charging HW Config: DC Supply Powered Charging HW Config: VBAT in Stage 2 (VS2) HW Config: Input Current Sense and Limit HW Config: Output Current Sense and Limit HW Config: Current Sense Filtering HW Config: Battery Temperature and Disconnect Sensing HW Config: SHDN Pin Connections HW Config: MODE Pin – Current Conduction Mode HW Config: Driving an LED with the STATUS Pin HW Config: I2C Chip Address Pin In-Situ Battery Charging Hot-Plugging Considerations STATUS Indicator Pin Lithium-Ion Battery Charging Lead-Acid Battery Charging Optional Features Optional: Low Power Mode Optional: Output Feedback Resistor Disconnect Optional: EXTVCC Disconnect Optional: Remote Battery Voltage Sensing Optional: DC Supply Detection Circuit Board Layout Considerations Design Example Typical Applications Package Description Typical Application Related Parts