Datasheet LT8491 (Analog Devices) - 10

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PIN FUNCTIONS FBIR (Pin 1):
A/D Input Pin. Connects to FBIN pin to mea-
SHDN (Pin 11):
Shutdown Pin. In conjunction with the sure input voltage. UVLO (undervoltage lockout) circuit, this pin is used to
CA (Pin 2):
A/D Input Pin. Connects to a resistor divider enable/disable the chip. Do not float this pin. to program the I2C address. This pin is measured during
CSN (Pin 12):
The (–) Input to the Inductor Current Sense the power up sequence. and Reverse Current Detect Amplifier.
TEMPSENSE (Pin 3):
A/D Input Pin. Connects to a therm-
CSP (Pin 13):
The (+) Input to the Inductor Current Sense istor divider network for sensing battery temperature or a and Reverse Current Detect Amplifier. The VC pin voltage resistor divider if unused. This pin is frequently monitored and built-in offsets between the CSP and CSN pins set the for temperature compensation and enforcing temperature inductor current trip threshold. limits.
LDO33 (Pin 14):
3.3V Regulator Output. This pin pro-
VDD (Pin 4):
I2C and Control Logic Power Supply Pin. vides power to the VDD and AVDD pins. Bypass this pin to Connect this pin to LDO33 and AVDD. ground with a minimum 4.7µF ceramic capacitor.
FBOW (Pin 5):
PWM Digital Output Pin. Connects to
FBIN (Pin 15):
Input Feedback Pin. This pin is connected FBOUT through an RCR network to temperature com- to the input error amplifier input. pensate the battery voltage.
FBOUT (Pin 16):
Output Feedback Pin. This pin connects
FBIW (Pin 6):
PWM Digital Output Pin. Connects to FBIN the error amplifier input to an external resistor divider through an RCR network to adjust the solar panel voltage from the output. for MPPT.
IMON_OUT (Pin 17):
Output Current Monitor and Limit
INTVCC (Pin 7):
Internal 6.35V Regulator Output Pin. Pin. The current out of this pin is proportional to the aver- Connects to the GATEVCC pin. INTVCC is powered from age output current. See the Applications Information sec- EXTVCC when the EXTVCC voltage is higher than 6.4V, tion for more information. otherwise INTVCC is powered from VIN. Bypass this pin
V
to ground with a minimum 4.7µF ceramic capacitor. See
C (Pin 18):
Error Amplifier Output Pin. Tie the external compensation network to this pin. HW Config: MODE Pin - Current Conduction Mode for additional details.
SS (Pin 19):
Soft-Start Pin. Place 100nF of capacitance from this pin to ground. Upon start-up, this pin will be
SWEN (Pin 8):
Switch Enable Pin. Tie to the SWENO pin. charged by an internal resistor to 2.5V.
MODE (Pin 9):
Mode Pin. The voltage applied to this pin
CLKOUT (Pin 20):
Switching Regulator Clock Output Pin. sets the operating mode of the switching regulator. Tie CLKOUT will toggle at the same frequency as the switch- this pin to INTVCC to make discontinuous current mode ing regulator oscillator (OSC1 on the Block Diagram) or active. Tie this pin to ground to operate in discontinuous as the SYNC pin but is approximately 180° out-of-phase. current mode for low battery charging currents and con- CLKOUT can also be used as a temperature monitor of the tinuous current mode for high battery charging currents. switching regulator since the CLKOUT duty cycle varies Do not float this pin. See HW Config: MODE Pin - Current linearly with the junction temperature of the switching Conduction Mode for additional details. regulator. It is connected to the CLKDET pin through an
IMON_IN (Pin 10):
Input Current Monitor and Limit Pin. RC filter. The CLKOUT pin can drive capacitive loads up The current out of this pin is proportional to the input cur- to 200pF. rent. See the Applications Information section for more information. Rev. 0 10 For more information www.analog.com 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