BQ27541DRZR

bq27541 www.ti.com SLUS861 – DECEMBER 2008 Single Cell Li-Ion Battery Fuel Gauge for Battery Pack Integration Check for Samples: bq27541 FEATURES APPLICATIONS • • • • • • 1 23 • • • • Battery Fuel Gauge for 1-Series Li-Ion Applications Microcontroller Peripheral Provides: – Accurate Battery Fuel Gauging – Internal Temperature Sensor for System Temperature Reporting – SHA-1/HMAC Authentication – 96 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 (5 mΩ to 20 mΩ) HDQ and I2C™ Interface Formats for Communication with Host System 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 bq27541 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 for accurate battery fuel gauging. The bq27541 resides within the battery pack or on the system’s main-board with an embedded battery (nonremovable). The bq27541 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). The bq27541 also features integrated support for secure battery pack authentication, using the SHA-1/HMAC authentication algorithm. TYPICAL APPLICATION Battery Pack PACK+ Vcc REGIN LDO REG25 BAT SE HDQ bq27541 SDA TS SCL SRP PROTECTION IC Vss SRN PACK– 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 © 2008, Texas Instruments Incorporated bq27541 SLUS861 – DECEMBER 2008 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. DEVICE INFORMATION AVAILABLE OPTIONS PART NUMBER bq27541DRZR bq27541DRZT (1) PACKAGE TA COMMUNICATION FORMAT 12-pin, 2,5-mm × 4-mm SON –40°C to 85°C I2C, HDQ (1) TAPE and REEL QUANTITY 3000 250 bq27541 is shipped in I2C mode bq27541 (TOP VIEW) SE REG25 REGIN BAT Vcc Vss 1 2 3 4 5 6 12 11 10 9 8 7 HDQ SCL SDA TS SRN SRP TERMINAL FUNCTIONS TERMINAL NAME NO. DESCRIPTION TYPE (1) BAT 4 I Cell-voltage measurement input. ADC input. Decouple with 0.1mF capacitor. REG25 2 P 2.5V output voltage of the internal integrated LDO. Connect a minimum 0.47mF ceramic capacitor. REGIN 3 P The input voltage for the internal integrated LDO. Connect a 0.1mF ceramic capacitor. SCL 11 I Slave I2C serial communications clock input line for communication with system (Slave). Use with 10 kΩ pull-up resistor (typical). SDA 10 I/O Slave I2C serial communications data line for communication with system (Slave). Open-drain I/O. Use with 10 kΩ pull-up resistor (typical). SE 1 O Shutdown Enable output. Open-drain. HDQ 12 I/O HDQ serial communications line (Slave). Open-drain. SRN 8 IA Analog input pin connected to the internal coulomb counter where SRN is nearest the PACK- connection. Connect to 5-mΩ to 20-mΩ sense resistor. SRP 7 IA Analog input pin connected to the internal coulomb counter where SRP is nearest the CELL- connection. Connect to 5-mΩ to 20-mΩ sense resistor TS 9 IA Pack thermistor voltage sense (use 103AT-type thermistor). ADC input Vcc 5 P Processor power input. The minimum 0.47mF capacitor connected to REG25 should be close to Vcc. Vss 6 P Device ground (1) 2 I/O = Digital input/output, IA = Analog input, P = Power connection Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 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 Open-drain I/O pins (SDA, SCL, HDQ) –0.3 to 6 V BAT input, (pin 4) –0.3 to 6 V –0.3 to VCC + 0.3 V VI Regulator input, REGIN VCC Supply voltage range VIOD VBAT VI Input voltage range to all others (pins 1, 7, 8, 9) ESD Human Body Model (HBM), BAT pin 1.5 Human Body Model (HBM), all pins 2 kV TF Functional temperature range –40 to 100 °C Tstg Storage temperature range –65 to 150 °C (1) 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. DISSIPATION RATINGS (1) (2) PACKAGE (1) TA ≤ 40°C POWER RATING DERATING FACTOR TA ≤ 40°C RqJA 12-pin DRZ (2) 482 mW 5.67 mW/°C 176°C/W 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. This data is based on using a 4-layer JEDEC high-K board with the exposed die pad connected to a Cu pad on the board. The board pad is connected to the ground plane by a 2- × 2-via matrix. RECOMMENDED OPERATING CONDITIONS TA = -40°C to 85°C; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER Test CONDITION No operating restrictions MIN 2.7 5.5 2.7 Supply voltage, REGIN ICC Normal operating mode current I(SLP) Low-power operating mode current (1) I(FULLSLP) Low-power operating mode current (1) I(HIB) Hibernate operating mode current VOL Output voltage low (HDQ, SDA, SCL, SE) IOL = 3 mA VOH(PP) Output high voltage (SE) IOH = -1 mA VCC–0.5 VOH(OD) Output high voltage (HDQ, SDA, SCL) External pull-up resistor connected to Vcc VCC–0.5 VIL Input voltage low (HDQ, SDA, SCL) VIH Input voltage high (HDQ, SDA, SCL) V(A1) Input voltage range (TS) V(A2) Input voltage range (BAT) V(A3) Input voltage range (SRP, SRN) Ilkg Input leakage current (I/O pins) tPUCD Power-up communication delay (1) Fuel gauge in NORMAL mode. ILOAD > Sleep Current (1) (1) MAX 2.45 VI No FLASH writes TYP UNIT V 131 mA Fuel gauge in SLEEP mode. ILOAD < Sleep Current 60 mA Fuel gauge in FULLSLEEP mode. ILOAD < Sleep Current 21 mA Fuel gauge in HIBERNATE mode. ILOAD < Hibernate Current 6 mA 0.4 V V V –0.3 0.6 V 1.2 6 V VSS–0.125 2 V VSS–0.125 5 V VSS–0.125 0.125 V 0.3 mA 250 ms Specified by design. Not tested in production. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 3 bq27541 SLUS861 – DECEMBER 2008 www.ti.com POWER-ON RESET TA = –40°C to 85°C, C(REG) = 0.47mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER TEST CONDITIONS VIT+ Positive-going battery voltage input at VCC VHYS Power-on reset hysteresis MIN TYP MAX 2.05 2.20 2.31 UNIT V 45 115 185 mV 2.5 V LDO REGULATOR (1) TA = –40°C to 85°C, C(REG) = 0.47 mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER Regulator output voltage, REG25 VO TEST CONDITION MIN NOM MAX UNIT 2.48 2.57 V 2.7 V ≤ V(REGIN) ≤ 5.5 V, IOUT ≤ 16mA TA = –40°C to 85°C 2.42 2.45 V ≤ V(REGIN) < 2.7 V (low battery), IOUT ≤ 3mA TA = –40°C to 85°C 2.4 2.7 V, IOUT ≤ 16 mA V 280 VDO Regulator dropout voltage ΔV(REGTEMP) Regulator output change with temperature V(REGIN) = 3.6 V, IOUT = 16 mA ΔV(REGLINE) Line regulation 2.7 V ≤ V(REGIN) ≤ 5.5 V, IOUT = 16 mA 11 25 ΔV(REGLOAD) Load regulation 0.2 mA ≤ IOUT ≤ 3 mA, V(REGIN) = 2.45 V 34 40 3 mA ≤ IOUT ≤ 16 mA, V(REGIN) = 2.7 V 31 IOS (2) (1) (2) Short circuit current limit 2.45 V, IOUT ≤ 3 mA V(REG25) = 0 V, TA = –40°C to 85°C 50 TA = –40°C to 85°C mV 0.3% TA = –40°C to 85°C 250 mV mV mA LDO output current, IOUT, is the sum of internal and external load currents. Specified by design. Not production tested. INTERNAL TEMPERATURE SENSOR CHARACTERISTICS TA = –40°C to 85°C, C(REG) = 0.47mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER G(TEMP) TEST CONDITIONS MIN TYP Temperature sensor voltage gain MAX –2 UNIT mV/°C HIGH FREQUENCY OSCILLATOR TA = –40°C to 85°C, C(REG) = 0.47mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER fOSC fEIO tSXO (1) (2) (3) 4 TEST CONDITIONS MIN TYP 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 Operating frequency Frequency error (1) Start-up time (2) MAX 2.097 (3) UNIT MHz 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 © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 LOW FREQUENCY OSCILLATOR TA = –40°C to 85°C, C(REG) = 0.47mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER fOSC Frequency error (1) fEIO MIN TYP 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% Start-up time (3) tSXO (1) (2) (3) TEST CONDITIONS Operating frequency 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, C(REG) = 0.47mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER VIN(SR) tCONV(SR) TEST CONDITIONS Input voltage range, V(SRN) and V(SRP) VSR = V(SRN) – V(SRP) Conversion time Single conversion MIN 14 VOS(SR) Input offset INL Integral nonlinearity error ZIN(SR) Effective input resistance (1) Ilkg(SR) Input leakage current (1) MAX UNIT 0.125 V 1 Resolution (1) TYP –0.125 s 15 bits ±0.034 FSR 10 ±0.007 mV 2.5 MΩ 0.3 mA Specified by design. Not production tested. ADC (TEMPERATURE AND CELL MEASUREMENT) CHARACTERISTICS TA = –40°C to 85°C, C(REG) = 0.47mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER VIN(ADC) Input voltage range tCONV(ADC) Conversion time TEST CONDITIONS MIN –0.2 Resolution Input offset Z(ADC1) Effective input resistance (TS) Z(ADC2) Effective input resistance (BAT) (1) (1) UNIT V 125 ms 15 bits 1 (1) mV 8 bq27541 not measuring cell voltage MΩ 8 bq27541 measuring cell voltage Input leakage current MAX 1 14 VOS(ADC) Ilkg(ADC) TYP MΩ 100 (1) kΩ 0.3 mA Specified by design. Not production tested. DATA FLASH MEMORY CHARACTERISTICS TA = –40°C to 85°C, C(REG) = 0.47mF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) PARAMETER TEST CONDITIONS Data retention (1) tDR TYP MAX 10 Flash programming write-cycles (1) Word programming time ICCPROG Flash-write supply current (1) UNIT Years 20,000 Cycles (1) tWORDPROG (1) MIN 5 2 ms 10 mA Specified by design. Not production tested. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 5 bq27541 SLUS861 – DECEMBER 2008 www.ti.com HDQ COMMUNICATION TIMING CHARACTERISTICS TA = –40°C to 85°C, CREG = 0.47mF, 2.45 V < VREGIN = VBAT < 5.5 V; typical values at TA = 25°C and VREGIN = VBAT = 3.6 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX 205 250 ms 0.5 50 ms 32 50 ms Host sends 0 to bq27541 86 145 ms t(DW0) bq27541 sends 0 to host 80 145 ms t(RSPS) Response time, bq27541 to host 190 320 ms t(B) Break time 190 ms t(BR) Break recovery time 40 ms t(CYCH) Cycle time, host to bq27541 190 t(CYCD) Cycle time, bq27541 to host 190 t(HW1) Host sends 1 to bq27541 t(DW1) bq27541 sends 1 to host t(HW0) t(B) UNIT ms t(BR) (a) Break and Break Recovery t(DW1) t(HW1) t(HW0) t(DW0) t(CYCH) t(CYCD) (c) Gauge Transmit Bit (b) Host Transmitted Bit Break 7 - Bit Address 1-Bit R/W 8 - Bit Data t(RSPS) (d) Gauge to Host Response Figure 1. Timing Diagrams for HDQ Breaking (a), HDQ Host to bq27541 communication (b), bq27541 to Host communication (c), and bq27541 to Host response format (d). 6 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 I2C-COMPATIBLE INTERFACE COMMUNICATION TIMING CHARACTERISTICS TA = –40°C to 85°C, CREG = 0.47mF, 2.45 V < VREGIN = VBAT < 5.5 V; typical values at TA = 25°C and VREGIN = VBAT = 3.6 V (unless otherwise noted) MAX UNIT tr SCL/SDA rise time PARAMETER TEST CONDITIONS MIN TYP 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 1000 ns th(DAT) Data hold time 0 ns tsu(STOP) Setup time for stop 600 ns tBUF Bus free time between stop and start 1.3 fSCL Clock frequency ms 400 tSU(STA) tw(H) tf tw(L) tr kHz t(BUF) SCL SDA td(STA) tsu(STOP) tf tr th(DAT) tsu(DAT) REPEATED START STOP START Figure 2. I2C-Compatible Interface Timing Diagrams Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 7 bq27541 SLUS861 – DECEMBER 2008 www.ti.com GENERAL DESCRIPTION The bq27541 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 bq27541 control and status registers, as well as its data flash locations. Commands are sent from system to gauge using the bq27541’s serial communications engine, and can be executed during application development, pack manufacture, or end-equipment operation. Cell information is stored in the bq27541 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 bq27541’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 bq27541 provides 96 bytes of user-programmable data flash memory, partitioned into 3 32-byte blocks: Manufacturer Info Block A, Manufacturer Info Block B, and Manufacturer Info Block C. 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 bq27541’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 less than 1% error across a wide variety of operating conditions and over the lifetime of the battery. The bq27541 measures charge/discharge activity by monitoring the voltage across a small-value series sense resistor (5 mΩ to 20 mΩ typ.) located between the CELL- and the battery’s PACK- terminal. When a cell is attached to the bq27541, cell impedance is computed, based on cell current, cell open-circuit voltage (OCV), and cell voltage under loading conditions. The bq27501 external temperature sensing is optimized with the use of a high accuracy negative temperature coefficient (NTC) thermistor with R25 = 10KΩ ± 1% and B25/85 = 3435KΩ ± 1% (such as Semitec 103AT for measurement). The bq27501 can also be configured to use its internal temperature sensor. The bq27541 uses temperature to monitor the battery-pack environment, which is used for fuel gauging and cell protection functionality. To minimize power consumption, the bq27541 has different power modes: NORMAL, SLEEP, FULLSLEEP, HIBERNATE, and PRESHUTDOWN. The bq27541 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. e.g. RemainingCapacity( ) Data Flash: italics, bold, and breaking spaces. e.g. Design Capacity Register bits and flags: italics with brackets[]. e.g. [TDA] Data flash bits: italics, bold, and brackets[]. e.g: [LED1] Modes and states: ALL CAPITALS. e.g. UNSEALED mode 8 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 STANDARD DATA COMMANDS The bq27541 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. Table 1. Standard Commands NAME COMMAND CODE UNITS SEALED ACCESS Control( ) CNTL 0x00 / 0x01 N/A R/W AtRate( ) AR 0x02 / 0x03 mA R/W AtRateTimeToEmpty( ) ARTTE 0x04 / 0x05 Minutes R Temperature( ) TEMP 0x06 / 0x07 0.1K R Voltage( ) VOLT 0x08 / 0x09 mV R FLAGS 0x0a / 0x0b N/A R NominalAvailableCapacity( ) NAC 0x0c / 0x0d mAh R FullAvailableCapacity( ) FAC 0x0e / 0x0f mAh R RemainingCapacity( ) RM 0x10 / 0x11 mAh R FullChargeCapacity( ) FCC 0x12 / 0x13 mAh R Flags( ) AverageCurrent( ) AI 0x14 / 0x15 mA R TimeToEmpty( ) TTE 0x16 / 0x17 Minutes R TimeToFull( ) TTF 0x18 / 0x19 Minutes R StandbyCurrent( ) StandbyTimeToEmpty( ) MaxLoadCurrent( ) MaxLoadTimeToEmpty( ) SI 0x1a / 0x1b mA R STTE 0x1c / 0x1d Minutes R MLI 0x1e / 0x1f mA R MLTTE 0x20 / 0x21 Minutes R AvailableEnergy( ) AE 0x22 / 0x23 10 mWhr R AveragePower( ) AP 0x24 / 0x25 10 mW R TTEatConstantPower( ) TTECP 0x26 / 0x27 Minutes R Reserved RSVD 0x28 / 0x29 N/A R CC 0x2a / 0x2b Counts R SOC 0x2c / 0x2d % R CycleCount( ) StateOfCharge( ) Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 9 bq27541 SLUS861 – DECEMBER 2008 www.ti.com 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 bq27541 during normal operation and additional features when the bq27541 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 of 0x0541 (indicating bq27541) 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 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 SET_FULLSLEEP 0x0010 Yes Set the [FullSleep] bit in Control Status register to 1 SET_HIBERNATE 0x0011 Yes Forces CONTROL_STATUS [HIBERNATE] to 1 CLEAR_HIBERNATE 0x0012 Yes Forces CONTROL_STATUS [HIBERNATE] to 0 SET_SHUTDOWN 0x0013 Yes Enables the SE pin to change state CLEAR_SHUTDOWN 0x0014 Yes Disables the SE pin from changing state SEALED 0x0020 No Places the bq27541 is SEALED access mode IT_ENABLE 0x0021 No Enables the Impedance Track™ algorithm CAL_MODE 0x0040 No Places the bq27541 in calibration mode RESET 0x0041 No Forces a full reset of the bq27541 10 DESCRIPTION Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 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 SE FAS SS CSV CCA BCA – – Low Byte SHUTDOWN HIBERNATE FULLSLEEP SLEEP LDMD RUP_DIS VOK QEN SE = Status bit indicating the SE pin is active. True when set (i.e. SE pin is low) . Default is 0. FAS = Status bit indicating the bq27541 is in FULL ACCESS SEALED state. Active when set. SS = Status bit indicating the bq27541 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 bq27541 Coulomb Counter Calibration routine is active. Active when set. BCA = Status bit indicating the bq27541 Board Calibration routine is active. Active when set. SHUTDOWN = Control bit indicating the fuel gauge can force its SE pin low to signal an external shutdown. True when set. Default is 0. HIBERNATE = Status bit indicating a request for entry into HIBERNATE from SLEEP mode has been issued. True when set. Default is 0. Control bit when set will put the bq27541 into the lower power state of SLEEP mode. It is not possible to monitor this bit FULLSLEEP = because any communication will automatically clear it. The state can be detected by monitoring the power used by the bq27541. SLEEP = Status bit indicating the bq27541 is in SLEEP mode. True when set LDMD = Status bit indicating the bq27541 Impedance Track™ algorithm using constant-power mode. True when set. Default is 0 (constant-current mode). RUP_DIS = Status bit indicating the bq27541 Ra table updates are disabled. True when set. VOK = Status bit indicating cell voltages are OK for Qmax updates. True when set. QEN = Status bit indicating the bq27541 Qmax updates are enabled. True when set. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 11 bq27541 SLUS861 – DECEMBER 2008 www.ti.com 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. 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. CHEM_ID: 0X0008 Instructs the fuel gauge to return the chemical identifier for the Impedance Track™ configuration to addresses 0x00/0x01. SET_FULLSLEEP: 0X0010 Instructs the gas gauge to set the FullSleep bit in Control Status register to 1. This will allow the gauge to enter the FULLSLEEP power mode after the transition to SLEEP power state is detected. In FullSleep mode less power is consumed by disabling an oscillator circuit used by the communication engines. For HDQ communication one host message will be dropped. For I2C communications the first I2C message will incur a 6 – 8 millisecond clock stretch while the oscillator is started and stabilized. A communication to the device in FULLSLEEP will force the part back to the SLEEP mode. SET_HIBERNATE: 0X0011 Instructs the fuel gauge to force the CONTROL_STATUS [HIBERNATE] bit to 1. This will allow 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 will prevent 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_SHUTDOWN: 0X0013 Sets the CONTROL_STATUS [SHUTDOWN] bit to 1, thereby enabling the SE pin and CONTROL_STATUS [SE] bit to change state. The Impedance Track algorithm controls the setting of the SE pin and [SE] bit, depending on whether the conditions are met for fuel gauge shutdown or not. CLEAR_SHUTDOWN: 0X0014 Disables the SE pin from changing state. The SE pin is left in a high-impedance state. 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 active UpdateStatus location to 0x01 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. 12 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 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 AtRateTimeToEmpty( ) to return 65,535. Both the AtRate( ) and AtRateTimeToEmpty( ) commands should only be used in NORMAL mode. AtRateTimeToEmpty( ): 0x04/0x05 This read-only 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-only function returns an unsigned integer value of the battery temperature in units of 0.1K measured by the fuel gauge. Voltage( ): 0x08/0x09 This read-only 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-only 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 –– – – – – 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 = XCHG = Charge Inhibit indicates the temperature is outside the range [Charge Inhibit Temp Low, Charge Inhibit Temp High]. True when set Charge Suspend Alert indicates the temperature is outside the range [Suspend Temperature Low, Suspend Temperature High]. True when set FC = Full-charged condition reached (RMFCC=1; Set FC_Set%=-1% when RMFCC=0). True when set CHG = (Fast) charging allowed. True when set SOC1 = State-of-Charge-Threshold 1 (SOC1 Set) reached. True when set SOCF = State-of-Charge-Threshold Final (SOCF Set %) reached. True when set DSG = Discharging detected. True when set Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 13 bq27541 SLUS861 – DECEMBER 2008 www.ti.com NominalAvailableCapacity( ): 0x0c/0x0d This read-only command pair returns the uncompensated (less than C/20 load) battery capacity remaining. Units are mAh. FullAvailableCapacity( ): 0x0e/0x0f This read-only command pair returns the uncompensated (less than C/20 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. FullChargeCapacity( ): 0x12/13 This read-only command pair returns the compensated capacity of the battery when fully charged. Units are mAh. 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. 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 Current and is less than or equal to 2 x Initial Standby Current. 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 by taking approximate 93% weight of the last standby current and approximate 7% of the current measured average current. 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. 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. 14 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 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 mWh. AveragePower( ): 0x24/0x25 This read-word function returns an unsigned integer value of the average power of the current discharge. 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 1s. 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%. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 15 bq27541 SLUS861 – DECEMBER 2008 www.ti.com 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 commands 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 DFCLS 0x3e N/A N/A R/W DataFlashClass( ) (2) DataFlashBlock( ) (2) BlockData( ) / Authenticate( ) (3) BlockData( ) / AuthenticateCheckSum( ) (3) BlockData( ) DFBLK 0x3f N/A R/W R/W A/DF 0x40…0x53 N/A R/W R/W ACKS/DFD 0x54 N/A R/W R/W DFD 0x55…0x5f N/A R R/W BlockDataCheckSum( ) DFDCKS 0x60 N/A R/W R/W BlockDataControl( ) DFDCNTL 0x61 N/A N/A R/W DNAMELEN 0x62 N/A R R DNAME 0x63...0x69 N/A R R RSVD 0x6a...0x7f N/A R R DeviceNameLength( ) DeviceName( ) Reserved (1) (2) (3) 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. The BlockData( ) command area shares functionality for accessing general data flash and for using Authentication. See section on Authentication for more details. 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 0x00 to DataFlashBlock( ) specifies the BlockData( ) command will transfer authentication data. Issuing a 0x01, 0x02 or 0x03 instructs the BlockData( ) command to transfer Manufacturer Info Block A, B, or C, respectively. BlockData( ): 0x40…0x5f This command range is used to transfer data for data flash class access. This command range is the 32-byte data block used to access Manufacturer Info Block A, B, or C. Manufacturer Info Block A is read only for the sealed access. UNSEALED access is read/write. 16 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 BlockDataChecksum( ): 0x60 The host system should write this value to inform the device that new data is ready for programming into the specified data flash class and block.” 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, B, or C. 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. Reserved – 0x6a – 0x7f DATA FLASH INTERFACE Accessing the Data Flash The bq27541 data flash is a non-volatile memory that contains bq27541 initialization, default, cell status, calibration, configuration, and user information. The data flash can be accessed in several different ways, depending on what mode the bq27541 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 bq27541 is either in UNSEALED or SEALED modes. Most data flash locations, however, are only accessible in UNSEALED mode by use of the bq27541 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. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 17 bq27541 SLUS861 – DECEMBER 2008 www.ti.com 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 bq27541 — 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 bq27541 contains 96 bytes of user programmable data flash storage: Manufacturer Info Block A, Manufacturer Info Block B, Manufacturer Info Block C. 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 and 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. 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 bq27541 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 bq27541 provides three security modes (FULL ACCESS, UNSEALED, and SEALED) that control data flash access permissions according to Table 6. Data Flash refers to those data flash locations, specified in Table 7, that are accessible to the user. Manufacture Information refers to the three 32-byte blocks. Table 6. Data Flash Access Security Mode Data Flash Manufacturer Information FULL ACCESS R/W R/W UNSEALED R/W R/W SEALED None R (A); R/W (B,C) Although FULL ACCESS and UNSEALED modes appear identical, only FULL ACCESS mode allows the bq27541 to write access-mode transition keys. SEALING/UNSEALING DATA FLASH The bq27541 implements a key-access scheme to transition between SELAED, UNSEALED, and FULL-ACCESS modes. Each transition requires that a unique set of two keys be sent to the bq27541 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 2subcommands. When in SEALED mode the [SS] bit of CONTROL_STATUS is set, but when the UNSEAL keys are correctly received by the bq27541, the [SS] bit is cleared. When the full-access keys are correctly received then the CONTROL_STATUS [FAS] bit is cleared. 18 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 Both Unseal Key and Full-Access Key have two words and are stored in data flash. The first word is Key 0 and the second word is Key 1. The order of the keys sent to bq27541 are Key 1 followed by Key 0. The order of the bytes for each key entered through the Control( ) command is the reverse of what is read from the part. For an example, if the Unseal Key is 0x56781234, key 1 is 0x1234 and key 0 is 0x5678. Then Control( ) should supply 0x3412 and 0x7856 to unseal the part. The Unseal key and the FULL-ACCESS key cap only be updated when in FULL-ACCESS mode. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 19 bq27541 SLUS861 – DECEMBER 2008 www.ti.com 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 20 Class Subclass ID Subclass Offset Name Data Type Min Value Max Value Default Value Units Configuration 2 Safety 0 Configuration 2 Safety 2 OT Chg I2 0 1200 550 0.1°C OT Chg Time U1 0 60 2 Configuration 2 Safety 3 OT Chg Recovery s I2 0 1200 500 0.1°C Configuration 2 Safety 5 Configuration 2 Safety 7 OT Dsg I2 0 1200 600 0.1°C OT Dsg Time U1 0 60 2 Configuration 2 Safety 8 s OT Dsg Recovery I2 0 1200 550 0.1°C Configuration 32 Charge Inhibit Config Configuration 32 Charge Inhibit Config 0 Charge Inhibit Temp Low I2 –400 1200 0 0.1°C 2 Charge Inhibit Temp High I2 –400 1200 450 Configuration 32 0.1°C Charge Inhibit Config 4 Temp Hys I2 0 100 50 0.1°C Configuration Configuration 34 Charge 2 Charging Voltage I2 0 20,000 4200 mV 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 Termination 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 9 Terminate Charge Alarm Set % I1 -1 100 99 % Configuration 36 Charge Termination 10 Terminate Charge Alarm Clear % I1 -1 100 95 % Configuration 36 Charge Termination 11 Full Charge Set % I1 -1 100 100 % Configuration 36 Charge Termination 12 Full Charge Clear % I1 -1 100 98 % Configuration 48 Data 0 Remaining Capacity Alarm I2 0 70 100 mAh Configuration 48 Data 8 Initial Standby Current I1 –256 0 –10 mA Configuration 48 Data 9 Initial Max Load Current I2 –32,767 0 –500 mA Configuration 48 Data 17 Cycle Count U2 0 65535 0 Count Configuration 48 Data 19 CC Threshold I2 100 32,767 900 mAh Configuration 48 Data 23 Design Capacity I2 0 65,535 1000 mAh Configuration 48 Data 39 Device Name S8 x x bq27541 – Configuration 49 Discharge 0 SOC1 Set Threshold U1 0 255 150 mAh Configuration 49 Discharge 1 SOC1 Clear U1 0 255 175 mAh Configuration 49 Discharge 2 SOCF Set Threshold U1 0 255 75 mAh Configuration 49 Discharge 3 SOCF Clear 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 – System Data 58 Manufacturer Info 64–95 Block C [0–31] H1 0x00 0xff 0x00 – Configuration 64 Registers 0 Pack Configuration H2 0x0000 0xffff 0x0135 – Configuration 68 Power 0 Flash Update OK Voltage I2 0 4200 2800 mV Configuration 68 Power 7 Sleep Current I2 0 100 10 mA Configuration 68 Power 16 Hibernate Current U2 0 700 8 mA Configuration 68 Power 18 Hibernate Voltage U2 2400 3000 2550 mV Configuration 68 Power 20 Full Sleep Wait Time U1 0 255 0 s 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 48 Terminate Voltage I2 2800 3700 3000 mV Gas Gauging 80 IT Cfg 65 User Rate-mW I2 0 14,000 0 mW Gas Gauging 80 IT Cfg 67 Reserve Cap-mAh I2 0 9000 0 mAh Gas Gauging 80 IT Cfg 69 Reserve Cap-mWh I2 0 14,000 0 mWh Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 Table 7. Data Flash Summary (continued) Class Subclass ID Subclass Offset Name Data Type Min Value Max Value Default Value Units Gas Gauging 81 Current Thresholds Gas Gauging 81 Current Thresholds 0 Dsg Current Threshold I2 0 2000 60 mA 2 Chg Current Threshold I2 0 2000 75 Gas Gauging 81 mA Current Thresholds 4 Quit Current I2 0 1000 40 Gas Gauging mA 81 Current Thresholds 6 Dsg Relax Time U2 0 8191 1800 s Gas Gauging 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 82 State 0 Qmax Cell0 I2 0 32,767 1000 mAh Gas Gauging 82 State 2 Qmax I2 0 32,767 1500 mAh Gas Gauging 82 State 4 Cycle Count U2 0 65,535 0 – Gas Gauging 82 State 6 Update Status H1 0x00 0x03 0x00 – Gas Gauging 82 State 9 Avg I Last Run I2 –32,768 32,767 -299 mA Gas Gauging 82 State 11 Avg P Last Run I2 –32,768 32,767 -1131 mAh (1) (2) (3) Ra Tables 88 Pack Ra0 0–31 Ra Tables 89 Pack Ra0x 0–31 See (1) Calibration 104 Data 0 CC Gain F4 (2) 0.1 47 10 (3) mΩ Calibration 104 Data 4 CC Delta F4 (2) 4.7 188 10 (3) mΩ Calibration 104 Data 8 CC Offset I2 –2.4 24 –0.088 (3) 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 107 Current 1 Deadband U1 0 255 5 mA Security 112 Codes 0 Unseal Key H4 0x0000 0xffffffff 0x36720414 – Security 112 Codes 4 Full-Access Key H4 0x0000 0xffffffff 0xffffffff – Security 112 Codes 8 Authentication Key 3 H4 0x0000 0xffffffff 0x01234567 – Security 112 Codes 12 Authentication Key 2 H4 0x0000 0xffffffff 89ABCDEF – Security 112 Codes 16 Authentication Key 1 H4 0x0000 0xffffffff FEDCBA98 – Security 112 Codes 20 Authentication Key 0 H4 0x0000 0xffffffff 76543210 – Encoded battery profile information created by bqEasy software Not IEEE floating point Display as the value EVSW displayed. Data Flash value is different. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 21 bq27541 SLUS861 – DECEMBER 2008 www.ti.com FUNCTIONAL DESCRIPTION FUEL GAUGING The bq27541 measures the cell voltage, temperature, and current to determine battery SOC. The bq27541 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 bq27541 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 Terminate Voltage. NominalAvailableCapacity( ) and FullAvailableCapacity( ) are the uncompensated (no or light load) versions of RemainingCapacity( ) and FullChargeCapacity( ) respectively. The bq27541 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. 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 bq27541 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 1, the Constant Power Model is used. The [LDMD] bit of CONTROL_STATUS reflects the status of Load Mode. 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) 22 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. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 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) Power 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 value is in AtRate( ). 6 User_Rate-10mW: 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 capacity exists after reaching 0 RemainingCapacity( ), before Terminate Voltage is reached. A no-load rate of compensation is applied to this reserve. Reserve Cap-mWh Reserve Cap-mWh determines how much actual remaining capacity exists after reaching 0 AvailableEnergy( ), before Terminate Voltage is reached. A no-load rate of compensation is applied to this reserve capacity. Dsg Current Threshold This register is used as a threshold by many functions in the bq27541 to determine if actual discharge current is flowing into or out of the cell. The default for this register 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 bq27541 to determine if actual charge current is flowing into or out of the cell. The default for this register 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. 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 bq27541 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 that 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 bq27541 attempts to take accurate OCV readings. An additional requirement of dV/dt < 4 mV/sec is required for the bq27541 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. Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 23 bq27541 SLUS861 – DECEMBER 2008 www.ti.com Qmax Qmax contains the maximum chemical capacity of the active cell profiles, and is determined by comparing states of charge before and after applying the load with the amount of charge passed. They also correspond to capacity at low rate of discharge, such as C/20 rate. For high accuracy, this value is periodically updated by the bq27541 during operation. Based on the battery cell capacity information, the initial value of chemical capacity should be entered in Qmax field. The Impedance Track™ algorithm will update this value and maintain it in the Pack profile. Update Status Bit 0 (0x01) of the Update Status register indicates that the bq27541 has learned new Qmax parameters and is accurate. The remaining bits are reserved. Bits 0 is a status bit set by the bq27541. 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 bq27541. Avg I Last Run The bq27500 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 bq27541 when required. Avg P Last Run The bq27541 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 bq27541 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 bq27541 when required. Delta Voltage The bq27541 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. 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 prelearned pack (part of the process for creating golden image files). DETAILED PIN DESCRIPTIONS System Shutdown Enable (SE Pin) If the CONTROL_STATUS[SHUTDOWN] has been set, bq27541 will immediately pull the SE pin low at POR. The fuel gauge can be made to power-off through an external circuit when it releases the SE pin to high impedance. With an external circuit, this feature is useful to shutdown the fuel gauge in a deeply discharged battery to protect the battery. The SE pin is released to open drain state when the gauge enters HIBERNATE mode with the CONTROL_STATUS[HIBERNATE] and [SHUTDOWN] bits set. The Pack Configuration Register Some bq27541 pins are configured via the Pack Configuration data flash register, as indicated in Table 10. This register is programmed/read via the methods described in Section 1.2.1: Accessing the Data Flash. The register is located at subclass = 64, offset = 0. 24 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 Table 10. Pack Configuration Bit Definition bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 High Byte RESCAP – – – – IWAKE RSNS1 RSNS0 Low Byte – – SLEEP RMFCC SE_PU SE_POL – TEMPS RESCAP = No-load rate of compensation is applied to the reserve capacity calculation. True when set. Default is 0. IWAKE/RSNS1/RSNS0 = These bits configure the current wake function (see Table 11). Default is 0/0/1. 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. SE_PU = Pull-up enable for SE pin. True when set (push-pull). Default is 0. SE_POL = Polarity bit for SE pin. SE is active low when clear. Default is 1 (makes SE high when gauge is ready for shutdown). TEMPS = Selects external thermistor for Temperature( ) measurements. True when set. Default is 1. TEMPERATURE MEASUREMENT AND THE TS INPUT The bq27541 measures battery temperature via the TS input, in order to supply battery temperature status information to the fuel gauging algorithm and charger-control sections of the gauge. Alternatively, the gauge can also measure internal temperature via its on-chip temperature sensor, but only if the [TEMPS] bit of Pack 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 Section Standard Data Commands, for specific information). The thermistor circuit requires the use of an external 10Kohm thermistor with negative temperature coefficients, such as Semetic 103AT-type thermistor that connects between the Vcc and TS pins. Additional circuit information for connecting this thermistor to the bq27541 is shown in Section 4, Reference Schematic. OVERTEMPERATURE INDICATION 2.3.1 Overtemperature: 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. When Temperature( ) falls to OT Chg Recovery, the [OTC] of Flags( ) is reset. If OT Chg Time = 0, the feature is completely disabled. Overtemperature: 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. When Temperature( ) falls to OT Dsg Recovery, the [OTD] bit of Flags( ) is reset. If OT Dsg Time = 0, the feature is completely disabled. CHARGE-TERMINATION/-INHIBIT INDICATORS Detection Charge Termination For proper bq27541 operation, the cell charging voltage must be specified by the user. The default value for this variable is in the data flash Charging Voltage. The bq27541 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, Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 25 bq27541 SLUS861 – DECEMBER 2008 www.ti.com the [CHG] bit of Flags( ) is cleared. Also, if the [RMFCC] bit of Pack Configuration is set, and RemainingCapacity( ) is set equal to FullChargeCapacity( ). When TCA_Set is set to -1, it disables the use of the charger alarm threshold. In that case, TerminateCharge is set when the taper condition is detected. When FC_Set is set to -1, it disables the use of the full charge detection threshold. In that case, FullCharge is not set until the taper condition is met. Charge Inhibit The bq27541 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 [CHG_INH] of Flags( ) 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]. POWER MODES The bq27500 has three power modes: NORMAL, SLEEP, and HIBERNATE. In NORMAL mode, the bq27541 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. Finally, in HIBERNATE mode, the fuel gauge is in a low power state, but can be awaken by communication or certain I/O activity. 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. SLEEP Mode SLEEP mode is entered automatically if the feature is enabled (Pack 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 bq27541 performs an ADC autocalibration to minimize offset. While in SLEEP mode, the fuel gauge can suspend serial communications as much as 4ms by holding the comm line(s) low. This delay is necessary to correctly process host communication, since the fuel gauge processor is mostly halted in SLEEP mode. During the SLEEP mode, bq27541 periodically takes data measurements and updates its data set. However, a majority of its time is spent in an idle condition. The bq27541 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. FULLSLEEP Mode FULLSLEEP mode is entered automatically if the feature is enabled by setting the Pack Configuration [FULLSLEEP] bit in the Control Status register when the bq27541 is in SLEEP mode. The gauge exits the FULLSLEEP mode when there is any communication activity. Therefore, the execution of SET_FULLSLEEP sets [FULLSLEEP] bit, but EVSW might still display the bit clear. The FULLSLEEP mode can be verified by measuring the current consumption of the gauge. In this mode, the high frequency oscialliator is turned off. The power consumption is further reduced in this mode compared to the SLEEP mode. FULLSLEEP mode can also be entered by set the Full Sleep Wait Time to be a number larger than 0. The FULLSLEEP will be entered when the timer counts down to 0. This feature is disabled when the data flash is set as 0. During FULLSLEEP mode, the bq27541 periodically takes data measurements and updates its data set. However, a majority of its time is spent in an idle condition. The bq27541 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. 26 Submit Documentation Feedback Copyright © 2008, Texas Instruments Incorporated Product Folder Link(s): bq27541 bq27541 www.ti.com SLUS861 – DECEMBER 2008 While in FULLSLEEP mode, the fuel gauge can suspend serial communications as much as 4ms by holding the comm line(s) low. This delay is necessary correctly process host communication, since the fuel gauge processor is mostly halted in SLEEP mode. POR Exit From HIBERNATE VCELL < POR threshold Exit From HIBERNATE Communication Activity AND Comm address is for bq27541 OR bq27541 clears Control Status [HIBERNATE] = 0 Recommend Host also set Control Status [HIBERNATE] = 0 NORMAL Fuel gauging and data updated every 1s Exit From SLEEP Pack Configuration [SLEEP] = 0 OR | AverageCurrent( ) | > Sleep Current OR Current is Detected above IWAKE Entry to SLEEP Pack Configuration [SLEEP] = 1 AND | AverageCurrent( ) |≤ Sleep Current SLEEP Fuel gauging and data updated every 20 seconds HIBERNATE Wakeup From HIBERNATE Communication Activity AND Comm address is NOT for bq27541 Disable all bq27541 subcircuits except GPIO. Entry to WAITFULLSLEEP Full Sleep Wait Time > 0 WAITFULLSLEEP Exit From WAIT_HIBERNATE Host must set Control Status [HIBERNATE] = 0 AND VCELL > Hibernate Voltage Exit From WAIT_HIBERNATE Cell relaxed AND | AverageCurrent() | < Hibernate Current FULLSLEEP Count Down Entry to FULLSLEEP Host must set Control Status [FULLSLEEP] = 1 Entry to FULLSLEEP Count