bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 System-Side Impedance Track™ Fuel Gauge With Direct Battery Connection FEATURES APPLICATIONS • • • • • • 1 23 • • • • • Battery Fuel Gauge for 1-Series Li-Ion Applications Resides on System Main Board – Works with Embedded or Removable Battery Packs – Uses PACK+, PACK–, and T Battery Terminals – Can be Powered Directly From Battery Pack (no LDO required) Microcontroller Peripheral Provides: – Accurate Battery Fuel Gauging – Battery Low Interrupt Warning – Battery Insertion Indicator – 64 Bytes of Non-Volatile Scratch Pad FLASH Battery Fuel Gauging Based on Patented Impedance Track™ Technology – Models Battery Discharge Curve for Accurate Time-To-Empty Predictions – Automatically Adjusts for Battery Aging, Battery Self-Discharge, and Temperature/Rate Inefficiencies – Low-Value Sense Resistor (10 mΩ or less) I2C™ for Connection to System Microcontroller Port Small 12-pin 2,5 mm × 4 mm SON Package Smartphones PDAs Digital Still and Video Cameras Handheld Terminals MP3 or Multimedia Players DESCRIPTION The Texas Instruments bq27510-G2 system-side Li-Ion battery fuel gauge is a microcontroller peripheral that provides fuel gauging for single-cell Li-Ion battery packs. The device requires little system microcontroller firmware development. The bq27510-G2 resides on the system’s main board and manages an embedded battery (non-removable) or a removable battery pack. The bq27510-G2 uses the patented Impedance Track™ algorithm for fuel gauging, and provides information such as remaining battery capacity (mAh), state-of-charge (%), run-time to empty (min.), battery voltage (mV), and temperature (°C). Battery fuel gauging with the bq27510-G2 requires only PACK+ (P+), PACK– (P–), and Thermistor (T) connections to a removable battery pack or embedded battery. TYPICAL APPLICATION Host System Single-Cell Li-ion Battery Pack VCC REG25 REGIN LDO Battery Voltage Low Sense Warning Power Management Controller 2 IC DATA Temp Sense PACK+ PROTECTION IC T bq27510-G2 Battery Good PACK- FETs CHG DSG Current Sense 1 2 3 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Impedance Track is a trademark of Texas Instruments. I2C is a trademark of Phillips Corporation. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2010, Texas Instruments Incorporated bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. DEVICE INFORMATION AVAILABLE OPTIONS PART NUMBER (1) PACKAGE (2) TA COMMUNICATION FORMAT bq27510DRZR-G2 12-pin, 2,5-mm × 4-mm SON –40°C to 85°C I2C bq27510DRZT-G2 (1) (2) TAPE and REEL QUANTITY 3000 250 For bq27510-G1 users, please refer to "bq27510-G1 to bq27510-G2 CHANGE LIST" (SLUA567) for device change information. For the most current package and ordering information see the Package Option Addendum at the end of this document; or, see the TI website at www.ti.com. PIN DIAGRAM BI/TOUT 1 12 BAT_LOW/BAT_GD REG25 2 11 SCL REGIN 3 10 SDA BAT 4 9 TS Vcc 5 8 SRN Vss 6 7 SRP bq27510-G2 PIN FUNCTIONS PIN NAME TYPE (1) DESCRIPTION Battery-insertion detection input. Power pin for pack thermistor network. Thermistor-multiplexer control pin. Open-drain I/O. Use with pull-up resistor >1MΩ (1.8 MΩ typical). NO. BI/TOUT 1 I/O REG25 2 P 2.5 V output voltage of the internal integrated LDO. REGIN 3 P The input voltage for the internal integrated LDO. BAT 4 I Cell voltage measurement input. ADC input. Vcc 5 P Processor power input. Decouple with 0.1mF ceramic capacitor minimum. Vss 6 P Device ground SRP 7 IA Analog input pin connected to the internal coulomb counter where SRP is nearest the PACK-connection. Connect to 5-mΩ to 20-mΩ sense resistor. SRN 8 IA Analog input pin connected to the internal coulomb counter where SRN is nearest the VSS-connection. Connect to a 5-mΩ to 20-mΩ sense resistor. TS 9 IA Pack thermistor voltage sense (use 103AT-type thermistor). ADC input SDA 10 I/O Slave I2C serial communications data line for communication with system (Master). Open-drain I/O. Use with 10-kΩ pull-up resistor (typical). SCL 11 I Slave I2C serial communications clock input line for communication with system (Master). Use with 10-kΩ pull-up resistor (typical). BAT_LOW/ BAT_GD 12 O Battery-good or Battery-low output indicator. Desired function polarity selected through the Operation Configuration register. Open-drain output (1) 2 I/O = Digital input/output; IA = Analog input; P = Power connection. Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 ELECTRICAL SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) VALUE UNIT –0.3 to 24 V –0.3 to 2.75 V –0.3 to 6 V –0.3 to 6 V –0.3 to VCC + 0.3 V Functional temperature range –40 to 100 °C Storage temperature range –65 to 150 °C VREGIN Regulator input voltage VCC Supply voltage range VIOD Open-drain I/O pins (SDA, SCL, BAT_LOW/BAT_GD) VBAT BAT input pin VI Input voltage range to all other pins (TS, SRP, SRN, BI/TOUT) TF TSTG ESD (1) Human Body Model (HBM), BAT pin 1.5 Human Body Model (HBM), all other pins KV 2 Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. THERMAL INFORMATION bq27510-G2 THERMAL METRIC (1) DRZ (12-PINS) qJA Junction-to-ambient thermal resistance 64.1 qJCtop Junction-to-case (top) thermal resistance 59.8 qJB Junction-to-board thermal resistance 52.7 yJT Junction-to-top characterization parameter 0.3 yJB Junction-to-board characterization parameter 28.3 qJCbot Junction-to-case (bottom) thermal resistance 2.4 (1) UNITS °C/W For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. RECOMMENDED OPERATING CONDITIONS TA = 25°C, VCC = 2.5 V (unless otherwise noted) PARAMETER VREGIN Supply voltage TEST CONDITION No operating restrictions MIN TYP MAX 2.7 5.5 No FLASH writes 2.45 2.7 CREG25 0.47 CREG25 External REG25 capacitor tPUCD Power Up Communication Delay ICC Normal operating mode current Fuel gauge in NORMAL mode, ILOAD > Sleep Current ISLP Low-power operating mode current ISLP+ UNIT V µF 250 ms 103 mA Fuel gauge in SLEEP mode. ILOAD < Sleep Current 18 mA Low-power operating mode current Fuel gauge in SLEEP+ mode. ILOAD < Sleep Current 60 mA IHIB Hibernate operating mode current Fuel gauge in HIBERNATE mode. ILOAD < Hibernate Current 4 mA VOL Output voltage low (SDA, BAT_LOW, BI/TOUT) IOL = 0.5 mA VOH(PP) Output high voltage (BAT_LOW) IOH = –1 mA VCC–0.5 VOH(OD) Output high voltage (SDA, SCL, BI/TOUT) External pull-up resistor connected to Vcc VCC–0.5 VIL Input voltage low (SDA, SCL) Input voltage low (BI/TOUT) VIH(OD) BAT INSERT CHECK MODE active Input voltage high (SDA, SCL) Input voltage high (BI/TOUT) BAT INSERT CHECK MODE active 0.4 V V V –0.3 0.6 –0.3 0.6 1.2 6 1.2 6 V V VA1 Input voltage range (TS) VSS–0.125 2 V VA2 Input voltage range (BAT) VSS–0.125 5 V Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 3 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com RECOMMENDED OPERATING CONDITIONS (continued) TA = 25°C, VCC = 2.5 V (unless otherwise noted) PARAMETER VA3 Input voltage range (SRP, SRN) tPUCD Power-up communication delay TA Operating free-air temperature range 2.5 V LDO TEST CONDITION MIN TYP MAX VSS–0.125 0.125 250 UNIT V ms –40 85 °C (1) TA = 25°C, CREG = 0.47 mF, VREGIN = 3.6 V (unless otherwise noted) PARAMETER MIN NOM MAX 2.7 V ≤ VREGIN ≤ 5.5 V, IOUT ≤ 16mA TEST CONDITION TA = –40°C to 85°C 2.4 2.5 2.6 2.45 V ≤ VREGIN < 2.7 V (low battery), IOUT ≤ 3mA TA = –40°C to 85°C 2.40 2.7 V, IOUT ≤ 16 mA TA = –40°C to 85°C UNIT V VREG25 Regulator output voltage VDO Regulator dropout voltage ΔVREGTEMP Regulator output change with temperature VREGIN = 3.6 V, IOUT = 16 mA ΔVREGLINE Line regulation 2.7 V ≤ VREGIN ≤ 5.5 V, IOUT = 16 mA 11 25 mV ΔVREGLOAD Load regulation 0.2 mA ≤ IO UT ≤ 3 mA, VREGIN = 2.45 V 34 40 mV 3 mA ≤ IOUT ≤ 16 mA, VREGIN = 2.7 V 31 250 mA UNIT ISHORT (1) (2) (2) Short circuit current limit V 280 2.45 V, IOUT ≤ 3 mA mV 50 VREG25 = 0 V TA = –40°C to 85°C 0.3% TA = –40°C to 85°C LDO output current, IOUT, is the sum of internal and external load currents. Assured by design. Not production tested. POWER-ON RESET TA = –40°C to 85°C, typical values at TA = 25°C and VBAT = 3.6 V (unless otherwise noted) PARAMETER VIT+ Positive-going battery voltage input at VCC VHYS Power-on reset hysteresis TEST CONDITIONS MIN TYP MAX 2.05 2.20 2.31 V 45 115 185 mV INTERNAL TEMPERATURE SENSOR CHARACTERISTICS TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER GTEMP TEST CONDITIONS MIN Temperature sensor voltage gain TYP MAX –2 UNIT mV/°C HIGH FREQUENCY OSCILLATOR TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER fOSC fEIO tSXO (1) (2) (3) 4 TEST CONDITIONS MIN Operating frequency Frequency error (1) (2) Start-up time (3) TYP MAX 2.097 UNIT MHz TA = 0°C to 60°C –2.0% 0.38% 2.0% TA = –20°C to 70°C –3.0% 0.38% 3.0% TA = –40°C to 85°C -4.5% 0.38% 4.5% 2.5 5 ms The frequency error is measured from 2.097 MHz. The frequency drift is included and measured from the trimmed frequency at VCC = 2.5 V, TA = 25°C. The startup time is defined as the time it takes for the oscillator output frequency to be ±3% of typical oscillator frequency. Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 LOW FREQUENCY OSCILLATOR TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER fOSC tSXO (1) (2) (3) MIN TYP Operating frequency Frequency error (1) fEIO TEST CONDITIONS Start-up time MAX UNIT 32.768 (2) KHz TA = 0°C to 60°C –1.5% 0.25% 1.5% TA = –20°C to 70°C –2.5% 0.25% 2.5% TA = –40°C to 85°C -4.0% 0.25% 4.0% (3) 500 ms The frequency drift is included and measured from the trimmed frequency at VCC = 2.5 V, TA = 25°C. The frequency error is measured from 32.768 KHz. The startup time is defined as the time it takes for the oscillator output frequency to be ±3% of typical oscillator frequency. INTEGRATING ADC (COULOMB COUNTER) CHARACTERISTICS TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER TEST CONDITIONS VSR_IN Input voltage range, V(SRN) and V(SRP) VSR = V(SRN) – V(SRP) tSR_CONV Conversion time Single conversion MIN MAX UNIT 0.125 V 1 Resolution s 14 VSR_OS Input offset INL Integral nonlinearity error ZSR_IN Effective input resistance (1) ISR_LKG Input leakage current (1) (1) TYP –0.125 15 bits 10 ±0.007 mV ±0.034 %FSR 2.5 MΩ 0.3 mA Assured by design. Not production tested. ADC (TEMPERATURE AND CELL MEASUREMENT) CHARACTERISTICS TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER TEST CONDITIONS VADC_IN Input voltage range tADC_CONV Conversion time Resolution VADC_OS MIN Input offset UNIT V 125 ms 15 bits 1 (1) Effective input resistance (TS) ZADC2 Effective input resistance (BAT) (1) mV 8 bq27510-G2 not measuring cell voltage MΩ 8 bq27510-G2 measuring cell voltage (1) MAX 1 14 ZADC1 IADC_LKG TYP –0.2 MΩ 100 Input leakage current (1) kΩ 0.3 mA Assured by design. Not production tested. DATA FLASH MEMORY CHARACTERISTICS TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER tDR Data retention Flash programming write-cycles tWORDPROG) Word programming time (1) ICCPROG) Flash-write supply current (1) (1) TEST CONDITIONS (1) (1) MIN TYP MAX UNIT 10 Years 20,000 Cycles 5 2 ms 10 mA Assured by design. Not production tested. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 5 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com 400 kHz I2C-COMPATIBLE INTERFACE COMMUNICATION TIMING CHARACTERISTICS TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT tr SCL/SDA rise time 300 ns tf SCL/SDA fall time 300 ns tw(H) SCL pulse width (high) 600 ns tw(L) SCL pulse width (low) 1.3 ms tsu(STA) Setup for repeated start 600 ns td(STA) Start to first falling edge of SCL 600 ns tsu(DAT) Data setup time 100 ns th(DAT) Data hold time 0 ns tsu(STOP) Setup time for stop tBUF Bus free time between stop and start fSCL Clock frequency 600 ns 66 ms 400 kHz 100 kHz I2C-COMPATIBLE INTERFACE COMMUNICATION TIMING CHARACTERISTICS TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted) PARAMETER tr SCL/SDA rise time tf SCL/SDA fall time tw(H) SCL pulse width (high) tw(L) TEST CONDITIONS MIN TYP MAX 1 300 UNIT µs ns 4 µs SCL pulse width (low) 4.7 ms tsu(STA) Setup for repeated start 4.7 µs td(STA) Start to first falling edge of SCL 4 µs tsu(DAT) Data setup time 250 ns th(DAT) Data hold time Receive mode 0 ns Transmit mode 300 tsu(STOP) Setup time for stop tBUF Bus free time between stop and start fSCL Clock frequency tBUSERR Bus error timeout tSU(STA) tw(H) tf tw(L) 4 µs 4.7 ms 10 100 kHz 17.3 21.2 s tr t(BUF) SCL SDA td(STA) tsu(STOP) tf tr REPEATED START th(DAT) tsu(DAT) STOP START Figure 1. I2C-Compatible Interface Timing Diagrams 6 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 GENERAL DESCRIPTION The bq27510-G2 accurately predicts the battery capacity and other operational characteristics of a single Li-based rechargeable cell. It can be interrogated by a system processor to provide cell information, such as state-of-charge (SOC), time-to-empty (TTE) and time-to-full (TTF). Information is accessed through a series of commands, called Standard Commands. Further capabilities are provided by the additional Extended Commands set. Both sets of commands, indicated by the general format Command( ), are used to read and write information contained within the bq27510-G2 control and status registers, as well as its data flash locations. Commands are sent from system to gauge using the bq27510-G2’s I2C serial communications engine, and can be executed during application development, pack manufacture, or end-equipment operation. Cell information is stored in the bq27510-G2 in non-volatile flash memory. Many of these data flash locations are accessible during application development. They cannot, generally, be accessed directly during end-equipment operation. Access to these locations is achieved by either use of the bq27510-G2’s companion evaluation software, through individual commands, or through a sequence of data-flash-access commands. To access a desired data flash location, the correct data flash subclass and offset must be known. The bq27510-G2 provides 64 bytes of user-programmable data flash memory, partitioned into two 32-byte blocks: Manufacturer Info Block A and Manufacturer Info Block B. This data space is accessed through a data flash interface. For specifics on accessing the data flash, see section Manufacturer Information Blocks. The key to the bq27510-G2’s high-accuracy gas gauging prediction is Texas Instrument’s proprietary Impedance Track™ algorithm. This algorithm uses cell measurements, characteristics, and properties to create state-of-charge predictions that can achieve high accuracy across a wide variety of operating conditions and over the lifetime of the battery. The bq27510-G2 measures charge/discharge activity by monitoring the voltage across a small-value series sense resistor (5 mΩ to 20 mΩ typ.) located between the system’s Vss and the battery’s PACK– terminal. When a cell is attached to the bq27510-G2, cell impedance is computed, based on cell current, cell open-circuit voltage (OCV), and cell voltage under loading conditions. The bq27510-G2 can use an NTC thermistor (default is Semitec 103AT) for temperature measurement, or can also be configured to use its internal temperature sensor. The bq27510-G2 uses temperature to monitor the battery-pack environment, which is used for fuel gauging and cell protection functionality. To minimize power consumption, the bq27510-G2 has several power modes: NORMAL, SLEEP, HIBERNATE, and BAT INSERT CHECK. The bq27510-G2 passes automatically between these modes, depending upon the occurrence of specific events, though a system processor can initiate some of these modes directly. More details can be found in Section Power Modes. NOTE FORMATTING CONVENTIONS IN THIS DOCUMENT: Commands: italics with parentheses and no breaking spaces, RemainingCapacity( ). Data Flash: italics, bold, and breaking spaces, e.g. Design Capacity. Register bits and flags: brackets and italics, e.g. [TDA] Data flash bits: brackets, italics and bold, e.g: [LED1] Modes and states: ALL CAPITALS, e.g. UNSEALED mode. Copyright © 2010, Texas Instruments Incorporated e.g. Submit Documentation Feedback 7 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com DATA COMMANDS Standard Data Commands The bq27510-G2 uses a series of 2-byte standard commands to enable system reading and writing of battery information. Each standard command has an associated command-code pair, as indicated in Table 1. Because each command consists of two bytes of data, two consecutive I2C transmissions must be executed both to initiate the command function, and to read or write the corresponding two bytes of data. Additional options for transferring data, such as spooling, are described in Section, I2C INTERFACE. Standard commands are accessible in NORMAL operation. Read/Write permissions depend on the active access mode, SEALED or UNSEALED (for details on the SEALED and UNSEALED states, refer to Section Access Modes.) Table 1. Standard Commands NAME Control( ) COMMAND CODE UNITS SEALED ACCESS UNSEALED ACCESS CNTL 0x00 / 0x01 N/A R/W R/W AtRate( ) AR 0x02 / 0x03 mA R/W R/W AtRateTimeToEmpty( ) ARTTE 0x04 / 0x05 Minutes R R Temperature( ) TEMP 0x06 / 0x07 0.1K R R Voltage( ) VOLT 0x08 / 0x09 mV R R Flags( ) FLAGS 0x0a / 0x0b N/A R R NominalAvailableCapacity( ) NAC 0x0c / 0x0d mAh R R FullAvailableCapacity( ) FAC 0x0e / 0x0f mAh R R RemainingCapacity( ) RM 0x10 / 0x11 mAh R R FullChargeCapacity( ) FCC 0x12 / 0x13 mAh R R AI 0x14 / 0x15 mA R R TimeToEmpty( ) TTE 0x16 / 0x17 Minutes R R TimeToFull( ) TTF 0x18 / 0x19 Minutes R R SI 0x1a / 0x1b mA R R STTE 0x1c / 0x1d Minutes R R AverageCurrent( ) StandbyCurrent( ) StandbyTimeToEmpty( ) MaxLoadCurrent( ) MaxLoadTimeToEmpty( ) MLI 0x1e / 0x1f mA R R MLTTE 0x20 / 0x21 Minutes R R AE 0x22 / 0x23 mWhr R R AvailableEnergy( ) AveragePower( ) AP 0x24 / 0x25 mW R R TTEatConstantPower( ) TTECP 0x26 / 0x27 Minutes R R Reserved RSVD 0x28 / 0x29 N/A R R CC 0x2a / 0x2b Counts R R SOC 0x2c / 0x2d % R R CycleCount( ) StateOfCharge( ) Control(): 0x00/0x01 Issuing a Control( ) command requires a subsequent 2-byte subcommand. These additional bytes specify the particular control function desired. The Control( ) command allows the system to control specific features of the bq27510-G2 during normal operation and additional features when the bq27510-G2 is in different access modes, as described in Table 2. Table 2. Control( ) Subcommands CNTL FUNCTION CNTL DATA SEALED ACCESS CONTROL_STATUS 0x0000 Yes Reports the status of DF Checksum, Hibernate, IT, etc. DEVICE_TYPE 0x0001 Yes Reports the device type (0x0510) FW_VERSION 0x0002 Yes Reports the firmware version on the device type HW_VERSION 0x0003 Yes Reports the hardware version of the device type DF_CHECKSUM 0x0004 No Enables a data flash checksum to be generated and reports on a read RESET_DATA 0x0005 No Returns reset data 8 Submit Documentation Feedback DESCRIPTION Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 Table 2. Control( ) Subcommands (continued) CNTL FUNCTION CNTL DATA SEALED ACCESS DESCRIPTION Reserved 0x0006 No Not to be used PREV_MACWRITE 0x0007 No Returns previous MAC command code CHEM_ID 0x0008 Yes Reports the chemical identifier of the Impedance Track™ configuration BOARD_OFFSET 0x0009 No Forces the device to measure and store the board offset SET_HIBERNATE 0x0011 Yes Forces CONTROL_STATUS [HIBERNATE] to 1 CLEAR_HIBERNATE 0x0012 Yes Forces CONTROL_STATUS [HIBERNATE] to 0 SET_SLEEP+ 0x0013 Yes Forces CONTROL_STATUS [SNOOZE] to 1 CLEAR_SLEEP+ 0x0014 YES Forces CONTROL_STATUS [SNOOZE] to 0 SEALED 0x0020 No Places the bq27510-G2 in SEALED access mode IT_ENABLE 0x0021 No Enables the Impedance Track™ algorithm IF_CHECKSUM 0x0022 No Reports the instruction flash checksum CAL_MODE 0x0040 No Places the bq27510-G2 in calibration mode RESET 0x0041 No Forces a full reset of the bq27510-G2 CONTROL_STATUS: 0x0000 Instructs the fuel gauge to return status information to control addresses 0x00/0x01. The status word includes the following information. Table 3. CONTROL_STATUS Bit Definitions bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 High Byte – FAS SS CSV CCA BCA – – Low Byte – HIBERNATE SNOOZE SLEEP LDMD RUP_DIS VOK QEN FAS = Status bit indicating the bq27510-G2 is in FULL ACCESS SEALED state. Active when set. SS = Status bit indicating the bq27510-G2 is in the SEALED State. Active when set. CSV = Status bit indicating a valid data flash checksum has been generated. Active when set. CCA = Status bit indicating the bq27510-G2 coulomb counter calibration routine is active. Active when set. BCA = Status bit indicating the bq27510-G2 board calibration routine is active. Active when set. HIBERNATE = Status bit indicating a request for entry into HIBERNATE from SLEEP mode. True when set. Default is 0. SNOOZE = Status bit indicating the bq27510-G2 SLEEP+ mode is enabled. True when set. SLEEP = Status bit indicating the bq27510-G2 is in SLEEP mode. True when set. LDMD = Status bit indicating the bq27510-G2 Impedance Track™ algorithm using constant-power mode. True when set. Default is 0 (constant-current mode). RUP_DIS = Status bit indicating the bq27510-G2 Ra table update status. Updates disabled when set.. VOK = Status bit indicating cell voltages are OK for Qmax updates. True when set. QEN = Status bit indicating the bq27510-G2 Qmax updates enabled. True when set. DEVICE_TYPE: 0x0001 Instructs the fuel gauge to return the device type to addresses 0x00/0x01. FW_VERSION: 0x0002 Instructs the fuel gauge to return the firmware version to addresses 0x00/0x01. HW_VERSION: 0x0003 Instructs the fuel gauge to return the hardware version to addresses 0x00/0x01. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 9 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com DF_CHECKSUM: 0x0004 Instructs the fuel gauge to compute the checksum of the data flash memory. The checksum value is written and returned to addresses 0x00/0x01 (UNSEALED mode only). The checksum will not be calculated in SEALED mode; however, the checksum value can still be read. RESET_DATA: 0x0005 Instructs the fuel gauge to return the reset data to addresses 0x00/0x01, with the low byte (0x00) being the number of full resets and the high byte (0x01) the number of partial resets. PREV_MACWRITE: 0x0007 Instructs the fuel gauge to return the previous command written to addresses 0x00/0x01. The value returned is limited to less than 0x0015. CHEM_ID: 0x0008 Instructs the fuel gauge to return the chemical identifier for the Impedance Track™ configuration to addresses 0x00/0x01. BOARD_OFFSET: 0x0009 Instructs the fuel gauge to compute the coulomb counter offset with internal short and then without internal short applied across the SR inputs. The difference between the two measurements is the board offset. After a delay of approximately 32 seconds, this offset value is returned to addresses 0x00/0x01 and written to data flash. The CONTROL STATUS [BCA] is also set. The user must prevent any charge or discharge current from flowing during the process. This function is only available when the fuel gauge is UNSEALED. When SEALED, this command only reads back the board-offset value stored in data flash. SET_HIBERNATE: 0x0011 Instructs the fuel gauge to force the CONTROL_STATUS [HIBERNATE] bit to 1. This allows the gauge to enter the HIBERNATE power mode after the transition to SLEEP power state is detected. The [HIBERNATE] bit is automatically cleared upon exiting from HIBERNATE mode. CLEAR_HIBERNATE: 0x0012 Instructs the fuel gauge to force the CONTROL_STATUS [HIBERNATE] bit to 0. This prevents the gauge from entering the HIBERNATE power mode after the transition to SLEEP power state is detected. It can also be used to force the gauge out of HIBERNATE mode. SET_SLEEP+ : 0X0013 Instructs the fuel gauge to set the CONTROL_STATUS [SNOOZE] bit to 1. This enables the SLEEP+ mode. The gauge enters SLEEP+ power mode after the transition conditions are met. CLEAR_SLEEP+ MODE: 0X0014 Instructs the fuel gauge to set the CONTROL_STATUS [SNOOZE] bit to 0. This disables the SLEEP+ mode. The gauge exits from the SLEEP+ power mode after the SNOOZE bit is cleared. SEALED: 0x0020 Instructs the fuel gauge to transition from UNSEALED state to SEALED state. The fuel gauge should always be set to SEALED state for use in end equipment. IT_ENABLE: 0x0021 This command forces the fuel gauge to begin the Impedance Track™ algorithm, sets the bit 2 of UpdateStatus and causes the [VOK] and [QEN] flags to be set in the CONTROL_STATUS register. [VOK] is cleared if the voltages are not suitable for a Qmax update. Once set, [QEN] cannot be cleared. This command is only available when the fuel gauge is UNSEALED. 10 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 CAL_MODE: 0x0040 This command instructs the fuel gauge to enter calibration mode. This command is only available when the fuel gauge is UNSEALED. RESET : 0x0041 This command instructs the fuel gauge to perform a full reset. This command is only available when the fuel gauge is UNSEALED. AtRate( ): 0x02/0x03 The AtRate( ) read-/write-word function is the first half of a two-function command set used to set the AtRate value used in calculations made by the AtRateTimeToEmpty( ) function. The AtRate( ) units are in mA. The AtRate( ) value is a signed integer, with negative values interpreted as a discharge current value. The AtRateTimeToEmpty( ) function returns the predicted operating time at the AtRate value of discharge. The default value for AtRate( ) is zero and will force AtRate( ) to return 65,535. Both the AtRate( ) and AtRateTimeToEmpty( ) commands should only be used in NORMAL mode. AtRateTimeToEmpty( ): 0x04/0x05 This read-word function returns an unsigned integer value of the predicted remaining operating time if the battery is discharged at the AtRate( ) value in minutes with a range of 0 to 65,534. A value of 65,535 indicates AtRate( ) = 0. The fuel gauge updates AtRateTimeToEmpty( ) within 1 s after the system sets the AtRate( ) value. The fuel gauge automatically updates AtRateTimeToEmpty( ) based on the AtRate( ) value every 1s. Both the AtRate( ) and AtRateTimeToEmpty( ) commands should only be used in NORMAL mode. Temperature( ): 0x06/0x07 This read-word function returns an unsigned integer value of the battery temperature in units of 0.1K measured by the fuel gauge and has a range of 0 to 6553.5K. Voltage( ): 0x08/0x09 This read-word function returns an unsigned integer value of the measured cell-pack voltage in mV with a range of 0 to 6000 mV. Flags( ): 0x0a/0x0b This read-word function returns the contents of the gas-gauge status register, depicting the current operating status. Table 4. Flags Bit Definitions bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 High Byte OTC OTD – – CHG_INH XCHG FC CHG Low Byte – – OCV_GD WAIT_ID BAT_DET SOC1 SOCF DSG OTC = Over-Temperature in charge condition is detected. True when set. OTD = Over-Temperature in discharge condition is detected. True when set. CHG_INH = Charge Inhibit: unable to begin charging (temp outside the range [Charge Inhibit Temp Low, Charge Inhibit Temp High]). True when set. XCHG = Charge Suspend Alert (temp outside the range [Suspend Temperature Low, Suspend Temperature High]). True when set. FC = Full-charged condition reached. True when set. CHG = (Fast) charging allowed. True when set. OCV_GD = Good OCV measurement taken. True when set. WAIT_ID = Waiting to identify inserted battery. True when set. BAT_DET = Battery detected. True when set. SOC1 = State-of-Charge-Threshold 1 (SOC1 Set) reached. True when set. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 11 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com SOCF = State-of-Charge-Threshold Final (SOCF Set %) reached. True when set. DSG = Discharging detected. True when set. NominalAvailableCapacity( ): 0x0c/0x0d This read-only command pair returns the uncompensated (no load or light load) battery capacity remaining. Units are mAh. FullAvailableCapacity( ): 0x0e/0x0f This read-only command pair returns the uncompensated (no load or light load) capacity of the battery when fully charged. Units are mAh. FullAvailableCapacity( ) is updated at regular intervals, as specified by the IT algorithm. RemainingCapacity( ): 0x10/0x11 This read-only command pair returns the compensated battery capacity remaining. Units are mAh per bit. FullChargeCapacity( ): 0x12/13 This read-only command pair returns the compensated capacity of the battery when fully charged. Units are mAh per bit. FullChargeCapacity( ) is updated at regular intervals, as specified by the IT algorithm. AverageCurrent( ): 0x14/0x15 This read-only command pair returns a signed integer value that is the average current flow through the sense resistor. It is updated every 1 second. Units are mA per bit. TimeToEmpty( ): 0x16/0x17 This read-only function returns an unsigned integer value of the predicted remaining battery life at the present rate of discharge, in minutes. A value of 65,535 indicates battery is not being discharged. TimeToFull( ): 0x18/0x19 This read-only function returns an unsigned integer value of predicted remaining time until the battery reaches full charge, in minutes, based upon AverageCurrent( ). The computation accounts for the taper current time extension from the linear TTF computation based on a fixed AverageCurrent( ) rate of charge accumulation. A value of 65,535 indicates the battery is not being charged. StandbyCurrent( ): 0x1a/0x1b This read-only function returns a signed integer value of the measured standby current through the sense resistor. The StandbyCurrent( ) is an adaptive measurement. Initially it reports the standby current programmed in Initial Standby, and after spending some time in standby, reports the measured standby current. The register value is updated every 1 second when the measured current is above the Deadband (3mA default) and is less than or equal to 2 x Initial Standby. The first and last values that meet this criteria are not averaged in, since they may not be stable values. To approximate a 1-minute time constant, each new StandbyCurrent( ) value is computed as follows: StandbyCurrent( )NEW = (239/256) × StandbyCurrent( )OLD + (17/256) × AverageCurrent( ). StandbyTimeToEmpty( ): 0x1c/0x1d This read-only function returns an unsigned integer value of the predicted remaining battery life at the standby rate of discharge, in minutes. The computation uses Nominal Available Capacity (NAC), the uncompensated remaining capacity, for this computation. A value of 65,535 indicates battery is not being discharged. 12 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 MaxLoadCurrent( ): 0x1e/0x1f This read-only function returns a signed integer value, in units of mA, of the maximum load conditions. The MaxLoadCurrent( ) is an adaptive measurement which is initially reported as the maximum load current programmed in Initial Max Load Current. If the measured current is ever greater than Initial Max Load Current, then MaxLoadCurrent( ) updates to the new current. MaxLoadCurrent( ) is reduced to the average of the previous value and Initial Max Load Current whenever the battery is charged to full after a previous discharge to an SOC less than 50%. This prevents the reported value from maintaining an unusually high value. MaxLoadTimeToEmpty( ): 0x20/0x21 This read-only function returns an unsigned integer value of the predicted remaining battery life at the maximum load current discharge rate, in minutes. A value of 65,535 indicates that the battery is not being discharged. AvailableEnergy( ): 0x22/0x23 This read-only function returns an unsigned integer value of the predicted charge or energy remaining in the battery. The value is reported in units of 10mWh. AveragePower( ): 0x24/0x25 This read-only function returns a signed integer value of the average power of the current discharge. It is negative during discharge and positive during charge. A value of 0 indicates that the battery is not being discharged. The value is reported in units of mW. TimeToEmptyAtConstantPower( ): 0x26/0x27 This read-only function returns an unsigned integer value of the predicted remaining operating time if the battery is discharged at the AveragePower( ) value in minutes. A value of 65,535 indicates AveragePower( ) = 0. The fuel gauge automatically updates TimeToEmptyatContantPower( ) based on the AveragePower( ) value every 1 s. CycleCount( ): 0x2a/0x2b This read-only function returns an unsigned integer value of the number of cycles the battery has experienced with a range of 0 to 65,535. One cycle occurs when accumulated discharge ≥ CC Threshold. StateOfCharge( ): 0x2c/0x2d This read-only function returns an unsigned integer value of the predicted remaining battery capacity expressed as a percentage of FullChargeCapacity( ), with a range of 0 to 100%. Extended Data Commands Extended commands offer additional functionality beyond the standard set of commands. They are used in the same manner; however unlike standard commands, extended commands are not limited to 2-byte words. The number of command bytes for a given extended command ranges in size from single to multiple bytes, as specified in Table 5. For details on the SEALED and UNSEALED states, see Section Access Modes. Table 5. Extended Commands NAME COMMAND CODE UNITS SEALED ACCESS (1) (2) UNSEALED ACCESS (1) (2) R Reserved RSVD 0x34…0x3b N/A R DesignCapacity( ) DCAP 0x3c / 0x3d mAh R R DataFlashClass( ) (2) DFCLS 0x3e N/A N/A R/W DataFlashBlock( ) (2) DFBLK 0x3f N/A R/W R/W BlockData( ) DFD 0x40…0x5f N/A R R/W BlockDataCheckSum( ) DFDCKS 0x60 N/A R/W R/W BlockDataControl( ) DFDCNTL 0x61 N/A N/A R/W (1) (2) SEALED and UNSEALED states are entered via commands to Control( ) 0x00/0x01 In sealed mode, data flash CANNOT be accessed through commands 0x3e and 0x3f. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 13 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com Table 5. Extended Commands (continued) NAME DeviceNameLength( ) DeviceName( ) ApplicationStatus( ) Reserved COMMAND CODE UNITS SEALED ACCESS (1) (2) UNSEALED ACCESS (1) (2) DNAMELEN 0x62 N/A R R DNAME 0x63...0x69 N/A R R APPSTAT 0x6a N/A R R RSVD 0x6b...0x7f N/A R R DesignCapacity( ): 0x3c/0x3d SEALED and UNSEALED Access: This command returns the value is stored in Design Capacity and is expressed in mAh. This is intended to be the theoretical or nominal capacity of a new pack, but has no bearing on the operation of the fuel gauge functionality DataFlashClass( ): 0x3e UNSEALED Access: This command sets the data flash class to be accessed. The class to be accessed should be entered in hexadecimal. SEALED Access: This command is not available in SEALED mode. DataFlashBlock( ): 0x3f UNSEALED Access: This command sets the data flash block to be accessed. When 0x00 is written to BlockDataControl( ), DataFlashBlock( ) holds the block number of the data flash to be read or written. Example: writing a 0x00 to DataFlashBlock( ) specifies access to the first 32 byte block and a 0x01 specifies access to the second 32 byte block, and so on. SEALED Access: This command directs which data flash block will be accessed by the BlockData( ) command. Writing a 0x01 or 0x02 to DataFlashBlock( ) specifies the BlockData( ) command will transfer Manufacturer Info Block A or B, respectively. BlockData( ): 0x40…0x5f UNSEALED Access: This data block is the remainder of the 32 byte data block when accessing data flash. SEALED Access: This data block is the remainder of the 32 byte data block when accessing Manufacturer Block Info A or B. BlockDataChecksum( ): 0x60 UNSEALED Access: This byte contains the checksum on the 32 bytes of block data read or written to data flash. The least-significant byte of the sum of the data bytes written must be complemented ( [255 – x] , for x the least-significant byte) before being written to 0x60. SEALED Access: This byte contains the checksum for the 32 bytes of block data written to Manufacturer Info Block A or B. The least-significant byte of the sum of the data bytes written must be complemented ( [255 – x] , for x the least-significant byte) before being written to 0x60. BlockDataControl( ): 0x61 UNSEALED Access: This command is used to control data flash access mode. Writing 0x00 to this command enables BlockData( ) to access general data flash. Writing a 0x01 to this command enables SEALED mode operation of DataFlashBlock( ). SEALED Access: This command is not available in SEALED mode. DeviceNameLength( ): 0x62 UNSEALED and SEALED Access: This byte contains the length of the Device Name. DeviceName( ): 0x63…0x69 UNSEALED and SEALED Access: This block contains the device name that is programmed in Device Name 14 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 ApplicationStatus( ): 0x6a This byte function allows the system to read the bq27510-G2 Application Status data flash location. Refer to Table 6 for specific bit definitions. Reserved – 0x6b – 0x7f DATA FLASH INTERFACE Accessing the Data Flash The bq27510-G2 data flash is a non-volatile memory that contains bq27510-G2 initialization, default, cell status, calibration, configuration, and user information. The data flash can be accessed in several different ways, depending on what mode the bq27510-G2 is operating in and what data is being accessed. Commonly accessed data flash memory locations, frequently read by a system, are conveniently accessed through specific instructions, already described in Section Data Commands. These commands are available when the bq27510-G2 is either in UNSEALED or SEALED modes. Most data flash locations, however, are only accessible in UNSEALED mode by use of the bq27510-G2 evaluation software or by data flash block transfers. These locations should be optimized and/or fixed during the development and manufacture processes. They become part of a golden image file and can then be written to multiple battery packs. Once established, the values generally remain unchanged during end-equipment operation. To access data flash locations individually, the block containing the desired data flash location(s) must be transferred to the command register locations, where they can be read to the system or changed directly. This is accomplished by sending the set-up command BlockDataControl( ) (0x61) with data 0x00. Up to 32 bytes of data can be read directly from the BlockData( ) (0x40…0x5f), externally altered, then rewritten to the BlockData( ) command space. Alternatively, specific locations can be read, altered, and rewritten if their corresponding offsets are used to index into the BlockData( ) command space. Finally, the data residing in the command space is transferred to data flash, once the correct checksum for the whole block is written to BlockDataChecksum( ) (0x60). Occasionally, a data flash CLASS will be larger than the 32-byte block size. In this case, the DataFlashBlock( ) command is used to designate which 32-byte block the desired locations reside in. The correct command address is then given by 0x40 + offset modulo 32. For example, to access Terminate Voltage in the Gas Gauging class, DataFlashClass( ) is issued 80 (0x50) to set the class. Because the offset is 48, it must reside in the second 32-byte block. Hence, DataFlashBlock( ) is issued 0x01 to set the block offset, and the offset used to index into the BlockData( ) memory area is 0x40 + 48 modulo 32 = 0x40 + 16 = 0x40 + 0x10 = 0x50. Reading and writing subclass data are block operations up to 32 bytes in length. If during a write the data length exceeds the maximum block size, then the data is ignored. None of the data written to memory are bounded by the bq27510-G2– the values are not rejected by the fuel gauge. Writing an incorrect value may result in hardware failure due to firmware program interpretation of the invalid data. The written data is persistent, so a power-on reset does resolve the fault. MANUFACTURER INFORMATION BLOCKS The bq27510-G2 contains 64 bytes of user programmable data flash storage: Manufacturer Info Block A and Manufacturer Info Block B. The method for accessing these memory locations is slightly different, depending on whether the device is in UNSEALED or SEALED modes. When in UNSEALED mode, and when 0x00 has been written to BlockDataControl( ), accessing the Manufacturer Info Blocks is identical to accessing general data flash locations. First, a DataFlashClass( ) command is used to set the subclass, then a DataFlashBlock( ) command sets the offset for the first data flash address within the subclass. The BlockData( ) command codes contain the referenced data flash data. When writing the data flash, a checksum is expected to be received by BlockDataChecksum( ). Only when the checksum is received and verified is the data actually written to data flash. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 15 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com As an example, the data flash location for Manufacturer Info Block B is defined as having a Subclass = 58 and an Offset = 32 through 63 (32 byte block). The specification of Class = System Data is not needed to address Manufacturer Info Block B, but is used instead for grouping purposes when viewing data flash info in the bq27510-G2 evaluation software. When in SEALED mode or when 0x01 BlockDataControl( ) does not contain 0x00, data flash is no longer available in the manner used in UNSEALED mode. Rather than issuing subclass information, a designated Manufacturer Information Block is selected with the DataFlashBlock( ) command. Issuing a 0x01, 0x02, or 0x03 with this command causes the corresponding information block (A, B, or C, respectively) to be transferred to the command space 0x40…0x5f for editing or reading by the system. Upon successful writing of checksum information to BlockDataChecksum( ), the modified block is returned to data flash. Note: Manufacturer Info Block A is read-only when in SEALED mode. ACCESS MODES The bq27510-G2 provides three security modes (FULL ACCESS, UNSEALED, and SEALED) that control data flash access permissions according to Table 6. Public Access refers Data flash to those data flash locations, specified in Table 7, that are accessible to the user. Private Access refers to reserved data flash locations used by the bq27510-G2 system. Care should be taken to avoid writing to Private data flash locations when performing block writes in Full Access mode, by following the procedure outlined in ACCESSING THE DATAFLASH. Table 6. Data Flash Access Security Mode DF – Public Access DF – Private Access FULL ACCESS R/W R/W UNSEALED R/W R/W SEALED R N/A Although FULL ACCESS and UNSEALED modes appear identical, only FULL ACCESS mode allows the bq27510-G2 to write access-mode transition keys. SEALING/UNSEALING DATA FLASH The bq27510-G2 implements a key-access scheme to transition between SEALED, UNSEALED, and FULL-ACCESS modes. Each transition requires that a unique set of two keys be sent to the bq27510-G2 via the Control( ) control command. The keys must be sent consecutively, with no other data being written to the Control( ) register in between. Note that to avoid conflict, the keys must be different from the codes presented in the CNTL DATA column of Table 2 subcommands. When in SEALED mode the [SS] bit of CONTROL_STATUS is set, but when the UNSEAL keys are correctly received by the bq27510-G2, the [SS] bit is cleared. When the full-access keys are correctly received then the CONTROL_STATUS [FAS] bit is cleared. Both the sets of keys for each level are 2 bytes each in length and are stored in data flash. The UNSEAL key (stored at Unseal Key 0 and Unseal Key 1) and the FULL-ACCESS key (stored at Full Access Key 0 and Full Access Key 1) can only be updated when in FULL-ACCESS mode. The order of the bytes entered through the Control( ) command is the reverse of what is read from the part. For example, if the 1st and 2nd word of the UnSeal Key 0 returns 0x1234 and 0x5678, then Control( ) should supply 0x3412 and 0x7856 to unseal the part. 16 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 DATA FLASH SUMMARY Table 7 summarizes the data flash locations available to the user, including their default, minimum, and maximum values. Table 7. Data Flash Summary Class Subclass ID Subclass Offset Configuration 2 Safety 0 Configuration 2 Safety 2 Configuration 2 Safety Configuration 2 Configuration 2 Configuration Name Data Type Min Value Max Value Default Value Units OT Chg I2 0 1200 550 0.1°C OT Chg Time U1 0 60 2 s 3 OT Chg Recovery I2 0 1200 500 0.1°C Safety 5 OT Dsg I2 0 1200 600 0.1°C Safety 7 OT Dsg Time U1 0 60 2 s 2 Safety 8 OT Dsg Recovery I2 0 1200 350 0.1°C Configuration 32 Charge Inhibit Config 0 Charge Inhibit Temp Low I2 –400 1200 0 0.1°C Configuration 32 Charge Inhibit Config 2 Charge Inhibit Temp High I2 –400 1200 450 0.1°C Configuration 32 Charge Inhibit Config 4 Temp Hys I2 0 100 50 0.1°C Configuration 34 Charge 2 Charging Voltage I2 0 4600 4200 mV Configuration 34 Charge 4 Delta Temperature I2 0 500 50 0.1°C Configuration 34 Charge 6 Suspend Temperature Low I2 –400 1200 –50 0.1°C Configuration 34 Charge 8 Suspend Temperature High I2 –400 1200 550 0.1°C Configuration 36 Charge Termination 2 Taper Current I2 0 1000 100 mA Configuration 36 Charge 4 Minimum Taper Charge I2 0 1000 25 0.01mAh Configuration 36 Charge Termination 6 Taper Voltage I2 0 1000 100 mV Configuration 36 Charge Termination 8 Current Taper Window U1 0 60 40 s Configuration 36 Charge Termination 7 TCA Set % I1 –1 100 100 % Configuration 36 Charge Termination 8 TCA Clear % I1 –1 100 95 % Configuration 36 Charge Termination 9 FC Set % I1 –1 100 100 % Configuration 36 Charge Termination 10 FC Clear % I1 –1 100 98 % Configuration 48 Data 4 Initial Standby Current I1 –128 0 –10 mA Configuration 48 Data 5 Initial Max Load Current I2 –32,767 0 –500 mA Configuration 48 Data 7 CC Threshold I2 100 32,767 900 mAh Configuration 48 Data 10 Design Capacity I2 0 65,535 1000 mAh Configuration 48 Data 12 Device Name S8 x x bq27510 – Configuration 49 Discharge 0 SOC1 Set Threshold U1 0 255 150 mAh Discharge 1 SOC1 Clear Threshold U1 0 255 175 mAh Configuration 49 Discharge 2 SOCF Set Threshold U1 0 255 75 mAh Configuration 49 Discharge 3 SOCF Clear Threshold U1 0 255 100 mAh System Data 58 Manufacturer Info 0–31 Block A [0–31] H1 0x00 0xff 0x00 – System Data 58 Manufacturer Info 32–63 Block B [0–31] H1 0x00 0xff 0x00 – Configuration 64 Registers 0 Operation Configuration H2 0x0000 0xffff 0x0979 – Configuration 64 Registers 3 Operation Configuration B H1 0x00 0xff 0xC0 – Configuration 64 Registers 4 Batt Insert Delay U2 0 65535 0 – Configuration 64 Registers 6 Sleep Insert Delay U1 0 255 0 – Configuration 68 Power 0 Flash Update OK Voltage I2 0 4200 2800 mV Configuration 68 Power 5 Sleep Current I2 0 100 10 mA Configuration 68 Power 14 Hibernate Current U2 0 700 8 mA Configuration 68 Power 16 Hibernate Voltage U2 2400 3000 2550 mV Gas Gauging 80 IT Cfg 0 Load Select U1 0 255 1 – Gas Gauging 80 IT Cfg 1 Load Mode U1 0 255 0 – Gas Gauging 80 IT Cfg 23 Ra Filter U2 0 1000 800 – Gas Gauging 80 IT Cfg 44 Terminate Voltage I2 0 32,767 3000 mV Gas Gauging 80 IT Cfg 47 ResRelax Time U2 0 65535 200 s Gas Gauging 80 IT Cfg 49 User Rate-mA I2 2000 –100 0 mA Gas Gauging 80 IT Cfg 51 User Rate-mW I2 –7200 –350 0 10mW Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 17 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com Table 7. Data Flash Summary (continued) Class Subclass ID Subclass Offset Gas Gauging 80 IT Cfg 53 Gas Gauging 80 IT Cfg 55 Gas Gauging 80 IT Cfg Gas Gauging 81 Gas Gauging 81 Gas Gauging Name Data Type Min Value Max Value Default Value Reserve Cap-mAh I2 Reserve Cap-mWh I2 60 Ra Max Delta Current Thresholds 0 Current Thresholds 2 81 Current Thresholds Gas Gauging 81 Gas Gauging 0 –2000 –100 mAh 0 14,000 0 10mWh U2 0 65535 44 mohms Dsg Current Threshold I2 0 2000 60 mA Chg Current Threshold I2 0 2000 75 mA 4 Quit Current I2 0 1000 40 mA Current Thresholds 6 Dsg Relax Time U2 0 8191 60 s 81 Current Thresholds 8 Chg Relax Time U1 0 255 60 s Gas Gauging 81 Current Thresholds 9 Quit Relax Time U1 0 63 1 s Gas Gauging 81 Current Thresholds 10 Transient Factor Charge U1 0 255 128 – Gas Gauging 81 Current Thresholds 11 Transient Factor Discharge U1 0 255 128 – Gas Gauging 81 Current Thresholds 12 Max IR Correct U2 0 1000 400 mV Gas Gauging 82 State 0 IT Enable H1 0x00 0xff 0x00 – Gas Gauging 82 State 1 Application Status H1 0x00 0xff 0x00 – Gas Gauging 82 State 2 Qmax 0 I2 0 32,767 1000 mAh Gas Gauging 82 State 4 Cycle Count 0 U2 0 65,535 0 – Gas Gauging 82 State 6 Update Status 0 H1 0x00 0x03 0x00 – Gas Gauging 82 State 7 Qmax 1 I2 0 32,767 1000 mAh Gas Gauging 82 State 9 Cycle Count 1 U2 0 65,535 0 Count Gas Gauging 82 State 11 Update Status 1 H1 0x00 0x03 0x00 – Gas Gauging 82 State 16 Avg I Last Run I2 –32,768 32,767 –300 mA Gas Gauging 82 State 18 Avg P Last Run I2 –32,768 32,767 –1200 mAh Gas Gauging 82 State 24 T Rise U2 0 65535 100 – Gas Gauging 82 State 26 T Time Constant U2 0 65535 1000 – – See (1) See (1) Units Default Ra Tables 87 Def0 Ra 0–18 Default Ra Tables 88 Def1 Ra 0–18 Ra Tables 91 Pack0 Ra 0–18 Ra Tables 92 Pack1 Ra 0–18 Ra Tables 93 Pack0 Rax 0–18 Ra Tables 94 Pack1 Rax 0–18 Calibration 104 Data 0 CC Gain F4 0.1 4 0.47095 Calibration 104 Data 4 CC Delta F4 2,9826 1,193,046 559,538.8 – Calibration 104 Data 8 CC Offset I2 –32768 32767 –1200 mV Calibration 104 Data 10 Board Offset I1 –128 127 0 mV Calibration 104 Data 11 Int Temp Offset I1 –128 127 0 0.1°C Calibration 104 Data 12 Ext Temp Offset I1 –128 127 0 0.1°C Calibration 104 Data 13 Pack V Offset I1 –128 127 0 mV Calibration 106 Temp Model 0–6 See Calibration 107 Current 1 Deadband U1 0 255 5 mA Security 112 Codes 0 Unseal Key 0 H2 0x0000 0xffff 0x3672 – Security 112 Codes 2 Unseal Key 1 H2 0x0000 0xffff 0x0414 – Security 112 Codes 4 Full-Access Key 0 H2 0x0000 0xffff 0xffff – Security 112 Codes 6 Full-Access Key 1 H2 0x0000 0xffff 0xffff – (1) 18 (1) Encoded battery profile information created by bqEasy software. Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 FUNCTIONAL DESCRIPTION FUEL GAUGING The bq27510-G2 measures the cell voltage, temperature, and current to determine battery SOC. The bq27510-G2 monitors charge and discharge activity by sensing the voltage across a small-value resistor (5 mΩ to 20 mΩ typ.) between the SRP and SRN pins and in series with the cell. By integrating charge passing through the battery, the battery’s SOC is adjusted during battery charge or discharge. The total battery capacity is found by comparing states of charge before and after applying the load with the amount of charge passed. When an application load is applied, the impedance of the cell is measured by comparing the OCV obtained from a predefined function for present SOC with the measured voltage under load. Measurements of OCV and charge integration determine chemical state of charge and chemical capacity (Qmax). The initial Qmax values are taken from a cell manufacturers' data sheet multiplied by the number of parallel cells. It is also used for the value in Design Capacity. The bq27510-G2 acquires and updates the battery-impedance profile during normal battery usage. It uses this profile, along with SOC and the Qmax value, to determine FullChargeCapacity( ) and StateOfCharge( ), specifically for the present load and temperature. FullChargeCapacity( ) is reported as capacity available from a fully charged battery under the present load and temperature until Voltage( ) reaches the Term Voltage. NominalAvailableCapacity( ) and FullAvailableCapacity( ) are the uncompensated (no or light load) versions of RemainingCapacity( ) and FullChargeCapacity( ) respectively. The bq27510-G2 has two flags accessed by the Flags( ) function that warns when the battery’s SOC has fallen to critical levels. When RemainingCapacity( ) falls below the first capacity threshold, specified in SOC1 Set Threshold, the [SOC1] (State of Charge Initial) flag is set. The flag is cleared once RemainingCapacity( ) rises above SOC1 Set Threshold. The bq27510-G2’s BAT_LOW pin automatically reflects the status of the [SOC1] flag. All units are in mAh. When RemainingCapacity( ) falls below the second capacity threshold, SOCF Set Threshold, the [SOCF] (State of Charge Final) flag is set, serving as a final discharge warning. If SOCF Set Threshold = –1, the flag is inoperative during discharge. Similarly, when RemainingCapacity( ) rises above SOCF Clear Threshold and the [SOCF] flag has already been set, the [SOCF] flag is cleared. All units are in mAh. IMPEDANCE TRACK™ VARIABLES The bq27510-G2 has several data flash variables that permit the user to customize the Impedance Track™ algorithm for optimized performance. These variables are dependent upon the power characteristics of the application as well as the cell itself. Load Mode Load Mode is used to select either the constant-current or constant-power model for the Impedance Track™ algorithm as used in Load Select (see Load Select). When Load Mode is 0, the Constant Current Model is used (default). When Load Mode is 1, the Constant Power Model is used. The [LDMD] bit of CONTROL_STATUS reflects the status of Load Mode. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 19 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com Load Select Load Select defines the type of power or current model to be used to compute load-compensated capacity in the Impedance Track™ algorithm. If Load Mode = 0 (Constant Current), then the options presented in Table 8 are available. Table 8. Constant-Current Model Used When Load Mode = 0 LoadSelect Value 0 1(default) Current Model Used Average discharge current from previous cycle: There is an internal register that records the average discharge current through each entire discharge cycle. The previous average is stored in this register. Present average discharge current: This is the average discharge current from the beginning of this discharge cycle until present time. 2 Average current: based off the AverageCurrent( ) 3 Current: based off of a low-pass-filtered version of AverageCurrent( ) (t=14s) 4 Design capacity / 5: C Rate based off of Design Capacity /5 or a C / 5 rate in mA. 5 AtRate (mA): Use whatever current is in AtRate( ) 6 User_Rate-mA: Use the value in User_Rate( ). This gives a completely user-configurable method. If Load Mode = 1 (Constant Power) then the following options are available: Table 9. Constant-Power Model Used When Load Mode = 1 LoadSelect Value 0(default) Current Model Used Average discharge power from previous cycle: There is an internal register that records the average discharge power through each entire discharge cycle. The previous average is stored in this register. 1 Present average discharge power: This is the average discharge power from the beginning of this discharge cycle until present time. 2 Average current × voltage: based off the AverageCurrent( ) and Voltage( ). 3 Current × voltage: based off of a low-pass-filtered version of AverageCurrent( ) (t=14s) and Voltage( ). 4 Design energy / 5: C Rate based off of Design Energy /5 or a C / 5 rate in mA. 5 AtRate (10 mW): Use whatever current is in AtRate( ) 6 User_Rate-10 mW: Use the value in User_Rate( ) mW. This gives a completely user-configurable method. Reserve Cap-mAh Reserve Cap-mAh determines how much actual remaining RemainingCapacity( ), before Terminate Voltage is reached. capacity exists after reaching 0 Reserve Cap-mWh Reserve Cap-mWh determines how much actual remaining capacity exists after reaching 0 AvailableEnergy( ), before Terminate Voltage is reached. Dsg Current Threshold This register is used as a threshold by many functions in the bq27510-G2 to determine if actual discharge current is flowing into or out of the cell. The default for this register is 60 mA which should be sufficient for most applications. This threshold should be set low enough to be below any normal application load current but high enough to prevent noise or drift from affecting the measurement. Chg Current Threshold This register is used as a threshold by many functions in the bq27510-G2 to determine if actual charge current is flowing into or out of the cell. The default for this register is 75 mA which should be sufficient for most applications. This threshold should be set low enough to be below any normal charge current but high enough to prevent noise or drift from affecting the measurement. 20 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 Quit Current, Dsg Relax Time, Chg Relax Time, and Quit Relax Time The Quit Current is used as part of the Impedance Track™ algorithm to determine when the bq27510-G2 enters relaxation mode from a current flowing mode in either the charge direction or the discharge direction. The value of Quit Current is set to a default value of 40 mA and should be above the standby current of the system. Either of the following criteria must be met to enter relaxation mode: 1. | AverageCurrent( ) | < | Quit Current | for Dsg Relax Time 2. | AverageCurrent( ) | > | Quit Current | for Chg Relax Time After about 30 minutes in relaxation mode, the bq27510-G2 attempts to take accurate OCV readings. An additional requirement of dV/dt 4 mV/sec is required for the bq27510-G2 to perform Qmax updates. These updates are used in the Impedance Track™ algorithms. It is critical that the battery voltage be relaxed during OCV readings to and that the current is not be higher than C/20 when attempting to go into relaxation mode. Quit Relax Time specifies the minimum time required for AverageCurrent( ) to remain above the QuitCurrent threshold before exiting relaxation mode. Qmax 0 and Qmax 1 Generically called Qmax, these dynamic variables contain the respective maximum chemical capacity of the active cell profiles, and are determined by comparing states of charge before and after applying the load with the amount of charge passed. They also correspond to capacity at very low rate of discharge, such as C/20 rate. For high accuracy, this value is periodically updated by the bq27510-G2 during operation. Based on the battery cell capacity information, the initial value of chemical capacity should be entered in the Qmax n field for each default cell profile. The Impedance Track™ algorithm updates these values and maintains them in the associated actual cell profiles. Update Status 0, Update Status 1 Bit 0 (0x01) of the Update Status n registers indicates that the bq27510-G2 has learned new Qmax parameters and is accurate. The remaining bits are reserved. Bits 0 is a status flag that can be set by the bq27510-G2 although a user can modify it. Bit 0 should never be modified except when creating a golden image file as explained in the application note Preparing Optimized Default Flash Constants for specific Battery Types (SLUA334.pdf). Bit 0 is updated as needed by the bq27510-G2. Avg I Last Run The bq27510-G2 logs the current averaged from the beginning to the end of each discharge cycle. It stores this average current from the previous discharge cycle in this register. This register should never need to be modified. It is only updated by the bq27510-G2 when required. Avg P Last Run The bq27510-G2 logs the power averaged from the beginning to the end of each discharge cycle. It stores this average power from the previous discharge cycle in this register. To get a correct average power reading the bq27510-G2 continuously multiplies instantaneous current times Voltage( ) to get power. It then logs this data to derive the average power. This register should never need to be modified. It is only updated by the bq27510-G2 when required. Delta Voltage The bq27510-G2 stores the maximum difference of Voltage( ) during short load spikes and normal load, so the Impedance Track™ algorithm can calculate remaining capacity for pulsed loads. It is not recommended to change this value. Batt Insert Delay, Sleep Insert Delay The Batt Insert Delay setting delays the bq27510-G2 detection process after battery insertion. Sleep Insert Delay specifies the delay before the gauge enters Sleep Mode after battery insertion. For proper operation, set Sleep Insert Delay greater than Batt Insert Delay. For example, with Batt Insert Delay = 10 ≤ (10,000ms) and Sleep Insert Delay = 15 s, the bq27510-G2 does not enter SLEEP mode before 5 seconds after the battery detection. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 21 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com Default Ra and Ra Tables These tables contain encoded data and, with the exception of the Default Ra Tables, are automatically updated during device operation. No user changes should be made except for reading/writing the values from a pre-learned pack (part of the process for creating golden image files). DETAILED PIN DESCRIPTIONS The Operation Configuration Register Some bq27510-G2 pins are configured via the Operation Configuration data flash register, as indicated in Table 5 3. This register is programmed/read via the methods described in Section Accessing the Data Flash. The register is located at subclass = 64, offset = 0. Table 10. Operation Configuration Bit Definition bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 High Byte RESCAP BATG_OVR I2C_NACK PFC_CFG1 PFC_CFG0 IWAKE RSNS1 RSNS0 Low Byte GNDSEL IDSELEN SLEEP RMFCC BATL_POL BATG_POL BAT_FN TEMPS RESCAP = No-load rate of compensation is applied to the reserve capacity calculation. True when set. Default is 0. BATG_OVR = BAT_GD override bit. If the gauge enters Hibernate only due to the cell voltage, the BAT_GD will not negate. True when set. Default is 0. I2C_NACK = I2C clock stretch control during data flash update. When this bit is set, the I2C engine clock stretch is disabled and NACK commands. When this bit is cleared, the I2C engine clock stretch is enabled. Default is 0. PFC_CFG1/PFC_CFG0 = Pin function code (PFC) mode selection: PFC 0, 1, or 2 selected by 0/0, 0/1, or 1/0, respectively. Default is PFC 1 (0/1). IWAKE/RSNS1/RSNS0 = These bits configure the current wake function (see Table 12). Default is 0/0/1. GNDSEL = The ADC ground select control. The Vss (Pin 6) is selected as ground reference when the bit is clear. Pin 7 is selected when the bit is set. Default is 0. IDSELEN = Enables cell profile selection feature. True when set. Default is 1. SLEEP = The fuel gauge can enter sleep, if operating conditions allow. True when set. Default is 1. RMFCC = RM is updated with the value from FCC, on valid charge termination. True when set. Default is 1 BATL_POL = BAT_LOW pin is active-high. True when set. Default is 1. BATG_POL = BAT_LOW/BAT_GD pin is active-low. True when cleared. Default is 0. BAT_FN = Selects BAT_LOW (bit clear) or /BAT_GD (bit set) function on pin 12. Default is 0. TEMPS = Selects external thermistor for Temperature( ) measurements. True when set. Default is 1. Some bq27510-G2 pins are configured via the Operation Configuration B data flash register, as indicated in Table 11. This register is programmed/read via the methods described in Section 4.2.1: Accessing the Data Flash. The register is located at subclass =64, offset = 0. Table 11. Operation Configuration B Bit Definition bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 RFACTSTEP SLPWKCHG -- -- -- -- -- -- RFACTSTEP = Use min and max res factor to limit resistance change. True when set. SLPWKCHG = Accumulates an extra 10 second x AverageCurrent() coulomb when waking from Sleep due to AverageCurrent() > Sleep Current . True when set. Default is 1. Pin Function Code Descriptions The bq27510-G2 has three possible pin-function variations that can be selected in accordance with the circuit architecture of the end application. Each variation has been assigned a pin function code, or PFC. When the PFC is set to 0, the bq27510-G2 measures battery temperature under all conditions. 22 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 A PFC of 1 is like a PFC of 0, except the BAT_LOW/BAT_GD pin is used to signal temperature thresholds during charge. If charging temperature falls outside of the preset range defined in data flash, a charger can be disabled via the BAT_LOW/BAT_GD pin, until cell temperature recovers. See Charge Inhibit for additional details. Finally when the PFC is set to 2, the battery thermistor can be shared between the fuel gauge and the charger. The charger has full usage of the thermistor during battery charging, while the fuel gauge uses the thermistor exclusively during discharge and battery relaxation. Thus temperature is not measured during charge. Note that removing the battery while charging will not result in BAT_DET clearing if PFC = 2. The PFC is specified in Operation Configuration [PFC_CFG1, PFC_CFG0]. The default is PFC = 1. BAT_LOW/BAT_GD Pin The BAT_LOW/BAT_GD is a multiplex pin. The function is defined by [BAT_FN] as a system processor with an electrical indicator of battery status. It the BAT_LOW function is activated, the signaling on the multiplexed pin follows the status of the [SOC1] bit in the Flags( ) register. Note that the polarity of the pin output can be inverted via the [BATL_POL] bit of the Operation Configuration. The bq27510-G2 must operate in conjunction with other electronics in a system appliance, such as chargers or other ICs and application circuits that draw appreciable power. After a battery is inserted into the system, there should be no charging or discharging current higher than C/20, so that an accurate OCV can be read. The OCV is used for helping determine which battery profile to use, as it constitutes part of the battery impedance measurement. When a battery is inserted into a system, the Impedance Track™ algorithm requires that no charging of the battery takes place and that any discharge is limited to less than C/20—these conditions are sufficient for the fuel gauge to take an accurate OCV reading. To disable these functions, the BAT_LOW/BAT_GD pin is merely set high (floating output pulled high). Once an OCV reading has be made, the BAT_LOW/BAT_GD pin is pulled low, thereby enabling battery charging and regular discharge of the battery. The Operation Configuration [BATG_POL] bit can be used to set the polarity of the battery good signal, should the default configuration need to be changed. The flowchart of Figure 2 details how the BAT_LOW/BAT_GD pin functions in the context of battery insertion and removal, as well as NORMAL vs. SLEEP modes when [BAT_FN] is set. In PFC 1, the BAT_LOW/BAT_GD pin is also used to disable battery charging when the bq27510-G2 reads battery temperatures outside the range defined by [Charge Inhibit Temp Low, Charge Inhibit Temp High]. The BAT_LOW/BAT_GD line is returned to "low" once temperature falls within the range [Charge Inhibit Temp Low + Temp Hys, Charge Inhibit Temp High – Temp Hys]. Battery Detection using the BI/TOUT Pin During power-up or hibernate activities, or any other activity where the bq27510-G2 needs to determine whether a battery is connected or not, the fuel gauge applies a test for battery presence. First, the BI/TOUT pin is put into high-Z status. The weak 1.8MΩ pull-up resistor will keep the pin high while no battery is present. When a battery is inserted (or is already inserted) into the system device, the BI/TOUT pin will be pulled low. This state is detected by the fuel gauge, which polls this pin every second when the gauge has power. A battery-disconnected status is assumed when the bq27510-G2 reads a thermistor voltage that is near 2.5V. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 23 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com Start Bq27500 POR No Batt detected? Yes Init (“BAT_GD” disabled, OCV taken, “BAT_GD enabled.) Battery Volt Sufficient to FG? No Yes NORMAL SLEEP Batt Present IT Operations (dsg, chg, rlx) Yes Bad batt detected? Yes No Batt removed? No Batt removed? Icc > Istandby -ORTr > 30min No Yes Yes No Batt Present -OR- bad batt (“BAT_GD” disabled) No Forced SLEEP Mode? Batt detected? No No Yes Yes Bad batt detected? No Yes AC or USB Present? No End Figure 2. BAT_LOW/BAT_GD Pin Operation, Based Upon Battery Presence and bq27510-G2 Operating Mode TEMPERATURE MEASUREMENT The bq27510-G2 measures battery temperature via its TS input, in order to supply battery temperature status information to the fuel gauging algorithm and charger-control sections of the gauge. Alternatively, it can also measure internal temperature via its on-chip temperature sensor, but only if the [TEMPS] bit of Operation Configuration register is cleared. Regardless of which sensor is used for measurement, a system processor can request the current battery temperature by calling the Temperature( ) function (see Standard Data Commands, for specific information). 24 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 The recommended thermistor circuit uses an external 103AT-type thermistor. Additional circuit information for connecting this thermistor to the bq27510-G2 is shown in REFERENCE SCHEMATIC. OVER-TEMPERATURE INDICATION Over-Temperature: Charge If during charging, Temperature( ) reaches the threshold of OT Chg for a period of OT Chg Time and AverageCurrent( ) > Chg Current Threshold, then the [OTC] bit of Flags( ) is set. If OT Chg Time = 0 then feature is completely disabled. When Temperature( ) falls to OT Chg Recovery, the [OTC] bit of Flags( ) is reset. Over-Temperature: Discharge If during discharging, Temperature( ) reaches the threshold of OT Dsg for a period of OT Dsg Time, and AverageCurrent( ) ≤ Dsg Current Threshold, then the [OTD] bit of Flags( ) is set. If OT Dsg Time = 0 then feature is completely disabled. CHARGING AND CHARGE-TERMINATION INDICATORS Detecting Charge Termination For proper bq27510-G2 operation, the cell charging voltage must be specified by the user. The default value for this variable is Charging Voltage = 4200mV. The bq27510-G2 detects charge termination when (1) during 2 consecutive periods of Current Taper Window, the AverageCurrent( ) is < Taper Current, (2) during the same periods, the accumulated change in capacity > 0.25mAh/ / Current Taper Window, and (3) Voltage( ) > Charging Voltage – Taper Voltage. When this occurs, the [CHG] bit of Flags( ) is cleared. Also, if the [RMFCC] bit of Operation Configuration is set, and RemainingCapacity( ) is set equal to FullChargeCapacity( ). Charge Inhibit When PFC = 1, the bq27510-G2 can indicate when battery temperature has fallen below or risen above predefined thresholds (Charge Inhibit Temp Low and Charge Inhibit Temp High, respectively). In this mode, the BAT_LOW/BAT_GD line is made high to indicate this condition, and is returned to its low state, once battery temperature returns to the range [Charge Inhibit Temp Low + Temp Hys, Charge Inhibit Temp High – Temp Hys]. When PFC = 0 or 2, the bq27510-G2 must be queried by the system in order to determine the battery temperature. At that time, the bq27510-G2 will sample the temperature. This saves battery energy when operating from battery, as periodic temperature updates are avoided during charging mode. POWER MODES The bq27510-G2 has four power modes: NORMAL, SLEEP, HIBERNATE and BAT INSERT CHECK. In NORMAL mode, the bq27510-G2 is fully powered and can execute any allowable task. In SLEEP mode the fuel gauge exists in a reduced-power state, periodically taking measurements and performing calculations. In HIBERNATE mode, the fuel gauge is in a very low power state, but can be woken up by communication. Finally, the BAT INSERT CHECK mode is a powered-up, but low-power halted, state, where the bq27510-G2 resides when no battery is inserted into the system. The relationship between these modes is shown in Figure 3. NORMAL Mode The fuel gauge is in NORMAL Mode when not in any other power mode. During this mode, AverageCurrent( ), Voltage( ) and Temperature( ) measurements are taken, and the interface data set is updated. Decisions to change states are also made. This mode is exited by activating a different power mode. Because the gauge consumes the most power in NORMAL mode, the Impedance Track™ algorithm minimizes the time the fuel gauge remains in this mode. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 25 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com SLEEP Mode SLEEP mode is entered automatically if the feature is enabled (Operation Configuration [SLEEP]) = 1) and AverageCurrent( ) is below the programmable level Sleep Current. Once entry into SLEEP mode has been qualified, but prior to entering it, the bq27510-G2performs an ADC autocalibration to minimize offset. During SLEEP mode, the bq27510-G2 periodically takes data measurements and updates its data set. However, a majority of its time is spent in an idle condition. The bq27510-G2 exits SLEEP if any entry condition is broken, specifically when: 1. AverageCurrent( ) rises above Sleep Current, or 2. a current in excess of IWAKE through RSENSE is detected. In the event that a battery is removed from the system while a charger is present (and powering the gauge), Impedance Track™ updates are not necessary. Hence, the fuel gauge enters a state that checks for battery insertion and does not continue executing the Impedance Track™ algorithm. SLEEP+ MODE Compared to the SLEEP mode, SLEEP+ mode has the high frequency oscillator in operation. The communication delay could be eliminated. The SLEEP+ is entered automatically if the feature is enabled (CONTROL STATUS [SNOOZE] = 1) and AverageCurrent( ) is below the programmable level Sleep Current. During SLEEP+ mode, the bq27510-G2 periodically takes data measurements and updates its data set. However, a majority of its time is spent in an idle condition. The bq27510-G2 exits SLEEP+ if any entry condition is broken, specifically when: 1. any communication activity with the gauge, or 2. AverageCurrent( ) rises above Sleep Current, or 3. a current in excess of IWAKE through RSENSE is detected. BAT INSERT CHECK Mode This mode is a halted-CPU state that occurs when an adapter, or other power source, is present to power the bq27510-G2 (and system), yet no battery has been detected. When battery insertion is detected, a series of initialization activities begin, which include: OCV measurement, setting the BAT_GD pin, and selecting the appropriate battery profiles. The setting of BAT_GD pin will experience longer delay (about 2 seconds) if other power source is not present when battery is inserted. Some commands, issued by a system processor, can be processed while the bq27510-G2 is halted in this mode. The gauge wakes up to process the command, then returns to the halted state awaiting battery insertion. 26 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 POR Exit From HIBERNATE Battery Removed BAT INSERT CHECK Exit From HIBERNATE Communication Activity AND Comm address is for bq27510 Check for battery insertion from HALT state. No gauging bq27510 clears Control Status [HIBERNATE ] = 0 Recommend Host also set Control Status [HIBERNATE] = 0 Flags [BAT _DET] = 0 Entry to NORMAL Exit From NORMAL Flags [BAT _DET] = 1 Flags [BAT _DET] = 0 Exit From SLEEP NORMAL Flags [BAT_DET] = 0 Fuel gauging and data updated every 1s HIBERNATE Wakeup From HIBERNATE Communication Activity AND Comm address is NOT for bq27510 Disable all bq27510 subcircuits except GPIO. Negate BAT_GD Exit From SLEEP | AverageCurrent( ) | > Sleep Current OR Current is Detected above IWAKE Entry to SLEEP+ Operation Configuration[SLEEP] = 1 AND Control Status[SNOOZE] = 1 AND | AverageCurrent( ) | ≤ Sleep Current Entry to SLEEP Operation Configuration[SLEEP] = 1 AND | AverageCurrent( ) | ≤ Sleep Current AND Control Status[SNOOZE] = 0 Exit From SLEEP+ Any communication to the gauge OR | AverageCurrent( ) | > Sleep Current OR Current is Detected above I WAKE SLEEP+ Fuel gauging and data updated every 20 seconds Both LFO and HFO are ON Exit From WAIT_HIBERNATE Cell relaxed AND | AverageCurrent() | < Hibernate Current WAIT_HIBERNATE Entry to SLEEP+ Control Status[SNOOZE] = 0 SLEEP OR V CELL Cell relaxed AND < Hibernate Voltage Entry to SLEEP+ Control Status[SNOOZE] = 1 Fuel gauging and data updated every 20 seconds BAT_GD unchanged Exit From WAIT _HIBERNATE Host must set Control Status [HIBERNATE ] = 0 AND VCELL > Hibernate Voltage System Shutdown Fuel gauging and data updated every 20 seconds (LFO ON and HFO OFF) Exit From SLEEP (Host has set Control Status [HIBERNATE] = 1 OR VCELL < Hibernate Voltage System Sleep Figure 3. Power Mode Diagram HIBERNATE Mode HIBERNATE mode could be used when the system equipment needs to enter a very low-power state, and minimal gauge power consumption is required. This mode is ideal when a system equipment is set to its own HIBERNATE, SHUTDOWN, or OFF modes. Before the fuel gauge can enter HIBERNATE mode, the system must set the [HIBERNATE] bit of the CONTROL_STATUS register. The gauge waits to enter HIBERNATE mode until it has taken a valid OCV measurement and the magnitude of the average cell current has fallen below Hibernate Current. The gauge can also enter HIBERNATE mode if the cell voltage falls below Hibernate Voltage. The gauge will remain in HIBERNATE mode until the system issues a direct I2C command to the gauge. I2C Communication that is not directed to the gauge will not wake the gauge (or at least for very long). It is important that BAT_LOW/BAT_GD be set to disable status (no battery charging/discharging). This prevents a charger application from inadvertently charging the battery before an OCV reading can be taken. It is the system’s responsibility to wake the bq27510-G2 after it has gone into HIBERNATE mode. After waking, the gauge can proceed with the initialization of the battery information (OCV, profile selection, etc.) It is suggested to keep the system in the SLEEP mode instead of HIBERNATE mode when a charger is attached. The reason is that charger removal will not wake up the battery from HIBERNATE mode. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 27 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com POWER CONTROL Reset Functions When the bq27510-G2 detects a software reset ([RESET] bit of Control( ) initiated), it determines the type of reset and increments the corresponding counter. This information is accessible by issuing the command Control( ) function with the RESET_DATA subcommand. As shown in Figure 4 if a partial reset was detected, a RAM checksum is generated and compared against the previously stored checksum. If the checksum values do not match, the RAM is reinitialized (a Full Reset). The stored checksum is updated every time RAM is altered. DEVICE RESET Generate Active RAM checksum value NO Stored checksum Do the Checksum Values Match? Re-initialize all RAM YES NORMAL OPERATION NO Active RAM changed ? YES Store checksum Generate new checksum value Figure 4. Partial Reset Flow Diagram Wake-Up Comparator The wake up comparator is used to indicate a change in cell current while the bq27510-G2 is in SLEEP mode or HIBERNATE modes. Operation Configuration uses bits [RSNS1–RSNS0] to set the sense resistor selection. Operation Configuration also uses the [IWAKE] bit to select one of two possible voltage threshold ranges for the given sense resistor selection. An internal interrupt is generated when the threshold is breached in either charge or discharge directions. Setting both [RSNS1] and [RSNS0] to 0 disables this feature. 28 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 Table 12. IWAKE Threshold Settings (1) (1) RSNS1 RSNS0 IWAKE Vth(SRP-SRN) 0 0 0 Disabled 0 0 1 Disabled 0 1 0 +1. 25 mV or –1.25 mV 0 1 1 +2.5 mV or –2.5 mV 1 0 0 +2.5 mV or –2.5 mV 1 0 1 +5 mV or –5 mV 1 1 0 +5 mV or –5 mV 1 1 1 +10 mV or –10 mV The actual resistance value versus the setting of the sense resistor is not important; just the actual voltage threshold when calculating the configuration. The voltage thresholds are typical values under room temperature. Flash Updates Data Flash can only be updated if Voltage( ) ≥ Flash Update OK Voltage. Flash programming current can cause an increase in LDO dropout. The value of Flash Update OK Voltage should be selected such that the bq27510-G2 Vcc voltage does not fall below its minimum of 2.4V during Flash write operations. AUTOCALIBRATION The bq27510-G2 provides an autocalibration feature that will measure the voltage offset error across SRP and SRN from time-to-time as operating conditions change. It subtracts the resulting offset error from normal sense resistor voltage, VSR, for maximum measurement accuracy. Autocalibration of the ADC begins on entry to SLEEP mode, except if Temperature( ) is ≤ 5°C or Temperature( ) = 45°C. The fuel gauge also performs a single offset when (1) the condition of AverageCurrent( ) ≤ 100mA and (2) {voltage change since last offset calibration ≥ 256mV} or {temperature change since last offset calibration is greater than 8°C for ≥ 60s}. Capacity and current measurements will continue at the last measured rate during the offset calibration when these measurements cannot be performed. If the battery voltage drops more than 32mV during the offset calibration, the load current has likely increased considerably; hence, the offset calibration will be aborted. APPLICATION-SPECIFIC INFORMATION BATTERY PROFILE STORAGE AND SELECTION Common Profile Aspects When a battery pack is removed from system equipment that implements the bq27510-G2, the fuel gauge maintains some of the battery information, in case it is re-inserted. This way the Impedance Track™ algorithm often has a means of recovering battery-status information, thereby maintaining good state-of-charge (SOC) estimates. Two default battery profiles are available to store battery information. They are used to provide the Impedance Track™ algorithm with the default information on two possible battery types expected to be used with the end-equipment. These default profiles can be used to support batteries of different chemistry, same chemistry but different capacities, or same chemistry but different models. Default profiles are programmed by the end-equipment manufacturer. Note that in the case of bq27510-G2, only one of the default profiles can be selected, and this selection cannot be changed during end-equipment operation. In addition to the default profiles, the bq27510-G2 maintains two active profiles: Cell0 and Cell1. These tables hold dynamic battery data, and keep track of the status for up to two of the most recent batteries used. In most cases the bq27510-G2 can administrate information on two removable battery packs. Copyright © 2010, Texas Instruments Incorporated Submit Documentation Feedback 29 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com Activities Upon Pack Insertion First OCV and Impedance Measurement At power-up the BAT_LOW/BAT_GD pin is inactive, so that the system cannot obtain power from the battery (this depends on actual implementation). In this state, the battery is put in an open-circuit condition. Next, the bq27510-G2 measures its first open-circuit voltage (OCV) via the BAT pin. From the OCV(SOC) table, the SOC of the inserted battery is found. Then the BAT_LOW/BAT_GD pin is made active, and the impedance of the inserted battery is calculated from the measured voltage and the load current: Z(SOC) = ( OCV(SOC) – V ) / I. This impedance is compared with the impedance of the dynamic profiles, Packn, and the default profiles, Defn, for the same SOC (the letter n depicts either a 0 or 1). Reading Application Status The Application Status data flash location contains cell profile status information, and can be read using the ApplicationStatus( ) Extended Command (0x6a). The bit configuration of this function/location is shown in Table 13. Table 13. ApplicationStatus( ) Bit Definitions (1) Application Configuration bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 Byte – – – – – – – LU_ PROF (1) LU_PROF = Last profile used by gas gauge. Cell0. last used when cleared. Cell1 last used when set. Default is 0. APPLICATION-SPECIFIC FLOW AND CONTROL The bq27510-G2 supports only one type of battery profile. This profile is stored in both the Def0 and Def1 profiles. When a battery pack is inserted for the first time, the default profile is copied into the Packn profiles. Then the Impedance Track™ algorithm begins gas gauging, regularly updating Packn as the battery is used. When an existing pack is removed from the bq27510-G2 and a different (or same) pack is inserted, cell impedance is measured immediately after battery detection. The bq27510-G2 chooses the profile which is closest to the measured impedance, starting with the Packn profiles. That is, if the measured impedance matches Pack0, then the Pack0 profile is used. If the measured impedance matches Pack1, then the Pack1 profile is used. If the measured impedance does not match the impedance stored in either Pack0 or Pack1, the battery pack is deemed new (none of the previously used packs). Either Def0/Def1 profile is copied into either the Pack0 or Pack1 profile, overwriting the oldest Packn profile. 30 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated bq27510-G2 www.ti.com SLUS948 – AUGUST 2010 COMMUNICATIONS I2C INTERFACE The fuel gauge supports the standard I2C read, incremental read, one-byte write quick read, and functions. The 7-bit device address (ADDR) is the most significant 7 bits of the hex address and is fixed as 1010101. The 8-bit device address is therefore 0xaa or 0xab for write or read, respectively. Fuel gauge generated Host generated ADDR[6:0] S 0 CMD[7:0] A DATA[7:0] A A P ADDR[6:0] S A 1 (a) 1- byte write ADDR[6:0] S A 0 DATA[7:0] N P N P (b) quick read CMD[7:0] ADDR[6:0] Sr A 1 A DATA[7:0] N P (c) 1 byte read ADDR[6:0] S 0 A CMD[7:0] A ADDR[6:0] Sr 1 DATA[7:0] A ... A DATA[7:0] (d) Incremental read (S = Start, Sr = Repeated Start, A = Acknowledge, N = No Acknowledge, and P = Stop) Figure 5. Supported I2C Formats The "quick read" returns data at the address indicated by the address pointer. The address pointer, a register internal to the I2C communication engine, increments whenever data is acknowledged by the bq27510-G2 or the I2C master. "Quick writes" function in the same manner and are a convenient means of sending multiple bytes to consecutive command locations (such as two-byte commands that require two bytes of data). Attempt to write a read-only address (NACK after data sent by master): S ADDR[6:0] 0 A A CMD[7:0] DATA[7:0] N P Attempt to read an address above 0x6B (NACK command): S 0 ADDR[6:0] CMD[7:0] A N P Attempt at incremental writes (NACK all extra data bytes sent): S ADDR[6:0] 0 A CMD[7:0] DATA[7:0] A A DATA[7:0] N ... N P Incremental read at the maximum allowed read address: S ADDR[6:0] 0 A CMD[7:0] A Address 0x7F Copyright © 2010, Texas Instruments Incorporated Sr ADDR[6:0] 1 A DATA[7:0] A Data from addr 0x7F DATA[7:0] N P Data from addr 0x00 Submit Documentation Feedback 31 bq27510-G2 SLUS948 – AUGUST 2010 www.ti.com REFERENCE SCHEMATIC 32 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated PACKAGE MATERIALS INFORMATION www.ti.com 16-Feb-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant BQ27510DRZR-G2 SON DRZ 12 3000 330.0 12.4 2.8 4.3 1.2 4.0 12.0 Q2 BQ27510DRZT-G2 SON DRZ 12 250 330.0 12.4 2.8 4.3 1.2 4.0 12.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 16-Feb-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) BQ27510DRZR-G2 SON DRZ 12 3000 338.1 338.1 20.6 BQ27510DRZT-G2 SON DRZ 12 250 338.1 338.1 20.6 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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