bq27541-V200 www.ti.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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 PRODUCTION PART # (1) bq27541DRZR-V200 bq27541DRZT-V200 (1) PACKAGE TA COMMUNICATION FORMAT 12-pin, 2.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 ELECTRICAL SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) VI Regulator input, REGIN VCC Supply voltage range VIOD Open-drain I/O pins (SDA, SCL, HDQ) VBAT BAT input, (pin 4) VI Input voltage range to all others (pins 1, 7, 8, 9) ESD 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.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com RECOMMENDED OPERATING CONDITIONS (continued) TA = -40°C to 85°C; typical values at TA = 25°C and V(REGIN) = VBAT = 3.6 V (unless otherwise noted) MIN tPUCD TYP Power-up communication delay MAX 250 UNIT ms POWER-ON RESET TA = –40°C to 85°C, C(REG) = 0.47μF, 2.45 V < V(REGIN) = VBAT < 5.5 V; typical values at TA = 25°C and V(REGIN) = VBAT = 3.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 LOW FREQUENCY OSCILLATOR TA = –40°C to 85°C, C(REG) = 0.47μF, 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 f(LOSC) Operating frequency f(LEIO) Frequency error (1) t(LSXO) (1) (2) (3) TEST CONDITIONS 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.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com HDQ COMMUNICATION TIMING CHARACTERISTICS TA = –40°C to 85°C, CREG = 0.47μF, 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 UNIT μs t(CYCH) Cycle time, host to bq27541 190 t(CYCD) Cycle time, bq27541 to host 190 250 μs t(HW1) Host sends 1 to bq27541 0.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 I2C-COMPATIBLE INTERFACE TIMING CHARACTERISTICS TA = –40°C to 85°C, CREG = 0.47μF, 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 UNIT 300 ns 300 ns tr SCL/SDA rise time tf SCL/SDA fall time tw(H) SCL pulse width (high) 600 ns tw(L) SCL pulse width (low) 1.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 DATA COMMANDS 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. Each protocol has specific means to access the data at each Command Code. DataRAM is updated and read by the gauge only once per second. Standard commands are accessible in NORMAL operation mode.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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 Flags bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 High Byte SE FAS SS CSV CCA BCA – HDQIntEn Low Byte SHUTDOWN HIBERNATE FULLSLEEP SLEEP LDMD RUP_DIS VOK QEN SE = Status bit indicating the SE pin is active. True when set.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 SET_HDQINTEN: 0x0015 Instructs the fuel gauge to set the CONTROL_STATUS [HDQIntEn] bit to 1. This will enable the HDQ Interrupt function. When this subcommand is received, the bq27541 will detect any of the interrupt conditions and assert the interrupt at one second intervals until the CLEAR_HDQINTEN command is received or the count of HDQHostIntrTries has lapsed (default 3).
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com 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 Low Byte OCVTAKEN – – – – XCHG FC CHG SOC1 SOCF DSG OTC = Over-Temperature in Charge condition is detected. True when set.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com StateOfHealth( ): 0x2e/0x2f 0x2e SOH percentage: this read-only function returns an unsigned integer value, expressed as a percentage of the ratio of predicted FCC(25°C, SOH current rate) over the DesignCapacity(). The FCC(25°C, SOH current rate) is the calculated full charge capacity at 25°C and the SOH current rate which is specified in the data flash (State of Health Load).
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com 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 the CONTROL_STATUS [FAS] bit is cleared. 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 Table 7.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com Table 7.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com If Load Mode = 1 (Constant Power) then the following options are available: Table 10. 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 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.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com Max DeltaV, Min DeltaV Maximal / Minimal value allowed for delta V, which will be subtracted from simulated voltage during remaining capacity simulation. Qmax Max Delta % Maximal change of Qmax during one update, as percentage of Design Capacity. If the gauges attempts to change Qmax exceeds this limit, changed value will be capped to old value ± DesignCapacity*QmaxMaxDelta / 100 DeltaV Max Delta Maximal change of Delta V value.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 The following bits are used to configure and control SE pin: • Two Control Status bits signals the operation of the SE pin: – SE – bit 15 – Status bit indicating the SE pin is active. Default is 0. – SHUTDOWN – bit 7 – Indicates the shutdown feature is enabled.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 The charging should not start when the temperature is below the Charge Inhibit Temp Low or above the Charge Inhibit Temp High. The charging can continue if the charging starts inside the window [Charge Inhibit Temp Low, Charge Inhibit Temp High] until the temperature is either below Suspend Temperature Low or above the Suspend Temperature High.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 Because the fuel gauge is dormant in HIBERNATE mode, the battery should not be charged or discharged in this mode, because any changes in battery charge status will not be measured. If necessary, the host equipment can draw a small current (generally infrequent and less than 1mA, for purposes of low-level monitoring and updating); however, the corresponding charge drawn from the battery will not be logged by the gauge.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com The fuel gauge also performs a single offset calibration 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 HDQ SINGLE-PIN SERIAL INTERFACE The HDQ interface is an asynchronous return-to-one protocol where a processor sends the command code to the bq27541. With HDQ, the least significant bit (LSB) of a data byte (command) or word (data) is transmitted first. Note that the DATA signal on pin 12 is open-drain and requires an external pull-up resistor.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com 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.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 I2C Command Waiting Time To make sure the correct results of a command with the 400KHz I2C operation, a proper waiting time should be added between issuing command and reading results. For subcommands, the following diagram shows the waiting time required between issuing the control command the reading the status with the exception of the checksum command.
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 www.ti.com REFERENCE SCHEMATIC J10 R20 4.7k R7, R8, and R9 are optional pull-down resistors if pull-up resistors are applied.
bq27541-V200 www.ti.com SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 REVISION HISTORY Text highlighted in red denotes important changes. Changes from Original (February 2010) to Revision A Page • Added: Available in I2C Mode only to the I(HIB) description ................................................................................................... 3 • Changed the Regulator output voltage, REG25 values, MIN From: 2.42, NOM From: 2.52, MAX From 2.57 ....................
bq27541-V200 SLUSA11B – FEBRUARY 2010 – REVISED SEPTEMBER 2013 Changes from Revision A (December 2010) to Revision B www.ti.com Page • Changed "Pack Configuration is set, and RemainingCapacity( ) is set " To: "Pack Configuration is set, then RemainingCapacity( ) is set" in the Detection Charge Termination section .......................................................................
PACKAGE OPTION ADDENDUM www.ti.
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