bq27410-G1
SLUSAF4 – MARCH 2011
www.ti.com
System-Side Impedance Track™ Fuel Gauge With Direct Battery Connection
FEATURES
APPLICATIONS
•
•
•
•
•
•
1
23
•
•
•
•
•
Battery Fuel Gauge for 1-Series LiCoO2 battery
Applications
Easy to Configure Battery Fuel Gauging Based
on Patented Impedance Track™ Technology
– Models Battery Discharge Curve for
Accurate State-of-Charge Report
– Automatically Adjusts for Battery Aging,
Battery Self-Discharge, and
Temperature/Rate Inefficiencies
– Low-Value Sense Resistor (5 mΩ or 20 mΩ)
Resides on System Main Board
– Works with Embedded or Removable
Battery Packs
– Integrated LDO allows devices to be
powered directly from battery pack
Microcontroller Peripheral Provides:
– Accurate Battery Fuel Gauging
– Internal Temperature Sensor for Battery
Temperature Reporting
– Configurable Level of State-of-Charge
(SOC) Interrupts
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 bq27410 system-side LiCoO2
battery fuel gauge is an easy to configure
microcontroller peripheral that provides fuel gauging
for single-cell LiCoO2 battery packs. The device
requires minimal user configurations and system
microcontroller firmware development for accurate
fuel gauging.
The bq27410 uses the patented Impedance Track™
algorithm for fuel gauging, and provides information
such as remaining battery capacity (mAh),
state-of-charge (%), and battery voltage (mV).
Battery fuel gauging with the bq27410 requires only
PACK+ (P+), PACK– (P–), for a removable battery
pack or embedded battery circuit. The 12-pin SON
package with dimensions of 2,5 mm × 4 mm with
0.5mm lead pitch is ideal for space constrained
applications.
TYPICAL APPLICATION
Single Cell Li- Ion
Battery Pack
Voltage
Sense
VBAT
REG 25
LDO
PACK +
PROTECTION
IC
REGIN
VCC
System
Interface
I2C
To Charger
bq27410
T
DATA
GPOUT
BIN
PACK -
SRP
SRN
FETs
CHG
DSG
Current
Sense
VSS
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 © 2011, Texas Instruments Incorporated
bq27410-G1
SLUSAF4 – MARCH 2011
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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
PACKAGE (1)
TA
COMMUNICATION
FORMAT
12-pin, 2,5-mm × 4-mm SON
–40°C to 85°C
I2C
PART NUMBER
bq27410DRZR-G1
bq27410DRZT-G1
(1)
TAPE and REEL
QUANTITY
3000
250
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
BIN
1
12
GPOUT
REG25
2
11
SCL
REGIN
3
10
SDA
bq27410-G1
BAT
4
9
NC
VCC
5
8
SRN
VSS
6
7
SRP
PIN FUNCTIONS
PIN
NAME
NO.
TYPE (1)
DESCRIPTION
BIN
1
I
Battery-insertion detection input. A logic high to low transition is detected as a battery insertion event.
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. Recommend 4.8V maximum for conversion accuracy.
Vcc
5
P
Processor power input. Decouple with minimum 0.1µF ceramic capacitor.
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 5-mΩ to 20-mΩ sense resistor.
NC
9
O
No Connect.
SDA
10
I/O
Slave I2C serial communications data line for communication with system (Master). Open-drain I/O. Use
with 10kΩ pull-up resistor (typical).
SCL
11
I
Slave I2C serial communications clock input line for communication with system (Master). Use with 10kΩ
pull-up resistor (typical).
GPOUT
12
O
General Purpose open-drain output. May be configured as Battery Low indicator or perform SOC interrupt
(SOC_INT) function.
(1)
2
I/O = Digital input/output; IA = Analog input; P = Power connection.
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ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range (unless otherwise noted) (1)
VALUE
UNIT
–0.3 to 2.75
V
Open-drain I/O pins (SDA, SCL, GPOUT)
–0.3 to 6
V
BAT input pin
–0.3 to 6
V
–0.3 to VCC + 0.3
V
VCC
Supply voltage range
VIOD
VBAT
VI
Input voltage range to all other pins (BIN, SRP, SRN)
ESD
Human Body Model (HBM), BAT pin
1.5
Human Body Model (HBM), all other pins
kV
2
TA
Operating free-air temperature range
–40 to 85
°C
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.
THERMAL INFORMATION
bq27410-G1
THERMAL METRIC (1)
DRZ (12-PINS)
θJA
Junction-to-ambient thermal resistance
64.1
θJCtop
Junction-to-case (top) thermal resistance
59.8
θJB
Junction-to-board thermal resistance
52.7
ψJT
Junction-to-top characterization parameter
0.3
ψJB
Junction-to-board characterization parameter
28.3
θJCbot
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 AND DC 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
VREGIN
Supply voltage
TEST CONDITION
MIN
No operating restrictions
TYP
MAX
2.7
5.5
No FLASH writes
2.45
2.7
0.47
V
µF
CREG25
External REG25 capacitor
CREG25
ICC
Normal operating mode current
Fuel gauge in NORMAL mode, ILOAD > Sleep Current
ISLP
Sleep operating mode current
IFULLSLP
Low-power operating mode current
IHIB
Hibernate operating mode current
Fuel gauge in HIBERNATE mode. ILOAD < Hibernate
Current
VOL
Output voltage low (Digital pins)
IOL = 0.5 mA
VOH(OD)
Output high voltage (SDA, SCL, GPOUT)
External pull-up resistor connected to Vcc
VIL
Input voltage low (SDA, SCL)
–0.3
0.6
Input voltage low (BIN)
–0.3
0.6
VIH(OD)
UNIT
103
μA
Fuel gauge in SLEEP mode. ILOAD < Sleep Current
60
μA
Fuel gauge in FULLSLEEP mode. ILOAD < Sleep
Current
18
μA
4
μA
0.4
VCC–0.5
V
V
Input voltage high (SDA, SCL)
1.2
6
Input voltage high (BIN)
1.2
VCC+0.3
V
V
VA2
Input voltage range (BAT)
VSS–0.125
5
VA3
Input voltage range (SRP, SRN)
VSS–0.125
0.125
V
Ilkg
Input leakage current (I/O pins)
0.3
µA
tPUCD
Power-up communication delay
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ms
3
bq27410-G1
SLUSAF4 – MARCH 2011
2.5 V LDO
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(1)
TA = –40°C to 85°C, typical values at TA = 25°C, CREG = 0.47µF and VBAT = 3.6 V (unless otherwise noted)
PARAMETER
VREG25
Regulator output voltage
TEST CONDITION
MIN NOM MAX
2.7 V ≤ VREGIN ≤ 5.5 V, IOUT ≤ 16 mA
2.4
2.45 V ≤ VREGIN < 2.7 V (low battery), IOUT ≤ 3 mA
2.4
2.6
V
2.7 V, IOUT ≤ 16 mA
280
mV
2.45 V, IOUT ≤ 3 mA
50
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, TA = 25°C
ΔVREGLOAD
Load regulation
ISHORT
(1)
(2)
(2)
Short circuit current limit
2.5
UNIT
V
0.3%
11
25
mV
0.2 mA ≤ IOUT ≤ 3 mA, VREGIN = 2.45 V, TA = 25°C
34
40
mV
3 mA ≤ IOUT ≤ 16 mA, VREGIN = 2.7 V, TA = 25°C
31
250
mA
VREG25 = 0 V, 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
UNIT
2.09
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
TEST CONDITIONS
MIN
TYP
MAX
UNIT
–2
GTEMP Temperature sensor voltage gain
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
Operating frequency
fEIO
Frequency error (1)
tSXO
Start-up time (3)
(1)
(2)
(3)
4
TEST CONDITIONS
(2)
MIN
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.
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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
Operating frequency
fEIO
Frequency error (1)
TEST CONDITIONS
MIN
TYP
MAX
32.76
8
(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%
tLSXO Start-up time (3)
(1)
(2)
(3)
UNIT
500
μs
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
–0.125
Input offset
INL
Integral nonlinearity error
ZSR_IN
Effective input resistance (1)
ISR_LKG
Input leakage current (1)
UNIT
0.125
V
s
14
VSR_OS
MAX
1
Resolution
(1)
TYP
15
bits
μV
10
±0.007
±0.034
%FSR
2.5
MΩ
μA
0.3
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
VADC_IN
Input voltage range
tADC_CONV
Conversion time
VADC_OS
Input offset
TEST CONDITIONS
ZADC2
IADC_LKG
(1)
TYP
–0.2
Resolution
ZADC1
MIN
MAX
UNIT
1
14
V
125
ms
15
bits
1
Effective input resistance (TS)
(1)
8
bq27410 not measuring cell voltage
Effective input resistance (BAT) (1)
Input leakage current
mV
MΩ
8
bq27410 measuring cell voltage
MΩ
100
(1)
kΩ
μA
0.3
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
TEST CONDITIONS
Data retention (1)
tDR
ICCPROG)
(1)
TYP
(1)
(1)
UNIT
Years
20,000
Cycles
Word programming time (1)
Flash-write supply current
MAX
10
Flash programming write-cycles
tWORDPROG)
MIN
5
2
ms
10
mA
Assured by design. Not production tested.
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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
tf
SCL/SDA fall time
300
tw(H)
SCL pulse width (high)
600
ns
tw(L)
SCL pulse width (low)
1.3
μs
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
600
ns
tBUF
Bus free time between stop and start
1.3
μs
fSCL
Clock frequency
400
ns
ns
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
UNIT
1
µs
300
ns
4
µs
SCL pulse width (low)
4.7
μs
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
0
ns
tsu(STOP)
Setup time for stop
4
µs
tBUF
Bus free time between stop and start
fSCL
Clock frequency
μs
4.7
100
tSU(STA)
tw(H)
tf
tw(L)
tr
kHz
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
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GENERAL DESCRIPTION
The bq27410 accurately predicts the battery capacity and other operational characteristics of a single LiCoO2
rechargeable cell. It can be interrogated by a system processor to provide cell information, such as
state-of-charge (SOC).
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 bq27410 control and status registers,
as well as its data flash locations. Commands are sent from system to gauge using the bq27410’s I2C serial
communications engine, and can be executed during application development, pack manufacture, or
end-equipment operation.
The key to the bq27410’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 bq27410 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 bq27410, cell impedance is computed, based on cell current, cell open-circuit voltage (OCV),
and cell voltage under loading conditions.
The bq27410 utilizes an integrated temperature sensor for estimating cell temperature. Alternatively, the host
processor can provide temperature data for the bq27410.
To minimize power consumption, the bq27410 has several power modes: INITIALIZATION, NORMAL, SLEEP,
FULLSLEEP, and HIBERNATE. The bq27410 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.
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e.g.
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DATA COMMANDS
Standard Data Commands
The bq27410 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
COMMAND CODE
UNITS
SEALED ACCESS
0x00 / 0x01
N/A
R/W
TEMP
0x02 / 0x03
0.1°K
R/W
VOLT
0x04 / 0x05
mV
R
FLAGS
0x06 / 0x07
N/A
R
NominalAvailableCapacity( )
NAC
0x08 / 0x09
mAh
R
FullAvailableCapacity( )
FAC
0x0a / 0x0b
mAh
R
RemainingCapacity( )
RM
0x0c / 0x0d
mAh
R
FullChargeCapacity( )
FCC
0x0e / 0x0f
mAh
R
AverageCurrent( )
AI
0x10 / 0x11
mA
R
StandbyCurrent( )
SI
0x12 / 0x13
mA
R
MaxLoadCurrent( )
MLI
0x14 / 0x15
mA
R
AvailableEnergy( )
AE
0x16 / 0x17
10mWhr
R
AveragePower( )
AP
0x18 / 0x19
10mW
R
StateOfCharge( )
SOC
0x1c / 0x1d
%
R
IntTemperature( )
ITEMP
0x1e / 0x1f
0.1°K
R
SCH
0x20 / 0x21
%
R
Control( )
CNTL
Temperature( )
Voltage( )
Flags( )
StateofHealth( )
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
bq27410 during normal operation and additional features when the bq27410 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 device.
DEVICE_TYPE
0x0001
Yes
Reports the device type (0x0410).
FW_VERSION
0x0002
Yes
Reports the firmware version on the device type.
HW_VERSION
0x0003
Yes
Reports the hardware version of the device type.
PREV_MACWRITE
0x0007
No
Returns previous MAC command code.
BAT_INSERT
0x000c
Yes
Forces the [BAT_DET] bit set when the [BIE] bit is 0.
BAT_REMOVE
0x000d
Yes
Forces the [BAT_DET] bit clear when the [BIE] bit is 0.
SET_FULLSLEEP
0x0010
Yes
Set CONTROL_STATUS [FULLSLEEP] to 1.
SET_HIBERNATE
0x0011
Yes
Forces CONTROL_STATUS [HIBERNATE] to 1.
CLEAR_HIBERNATE
0x0012
Yes
Forces CONTROL_STATUS [HIBERNATE] to 0.
FACTORY_RESTORE
0x0015
No
Forces a Factory Restore of learned resistance and Qmax to defaults.
SEALED
0x0020
No
Places the bq27410 in SEALED access mode.
RESET
0x0041
No
Forces a full reset of the bq27410.
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DESCRIPTION
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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
HIBE
FAS
SS
RSVD
CCA
RSVD
QMAXU
RESU
Low Byte
INITCOMP
HIBERNATE
FULLSLEEP
SLEEP
RSVD
RUP_DIS
VOK
RSVD
HIBE =
Status bit indicating that Hibernate mode has been Entered. The bit is cleared if a CLEAR_HIBERNATE subcommand is
received. Active when set.
FAS = Status bit indicating the bq27410 is in FULL ACCESS SEALED state. Active when set.
SS = Status bit indicating the bq27410 is in the SEALED State. Active when set.
CCA =
QMAXU =
Status bit indicating the bq27410 Coulomb Counter Auto-Calibration routine is active. The CCA routine will take place
approximately 3 minutes and 45 seconds after the initialization. Active when set.
Status bit indicating Qmax has Updated. True when set. This bit is cleared after power on reset or when [BAT_DET] bit is
set. When this bit is cleared, it enables fast learning of battery Qmax.
Status bit indicating that resistance has been updated. True when set. This bit is cleared after power on reset or when
RESU = [BAT_DET] bit is set. Also this bit can only be set after Qmax is updated or QMAXU is set. When this bit is cleared, it
enables fast learning of battery impedance.
INITCOMP = Initialization completion bit indicating the initialization completed. True when set.
HIBERNATE = Status bit indicating a request for entry into HIBERNATE from SLEEP mode has been issued. True when set. Default is 0.
FULLSLEEP =
Status bit indicating the BQ27410 is in FULLSLEEP mode. True when set. The state can be detected by monitoring the
power used by the BQ27410 because any communication will automatically clear it.
SLEEP = Status bit indicating the bq27410 is in SLEEP mode. True when set.
RSVD (bit 3) = This bit reserved and may change state at any time during device operation.
RUP_DIS = Status bit indicating the bq27410 Ra table updates are disabled. Updates disabled when set..
VOK = Status bit indicating cell voltages are OK for Qmax updates. True when set.
RSVD = Reserved for future use.
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.
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.
BAT_INSERT: 0X000C
This subcommand forces the Flags() [BAT_DET] bit to set when the battery insertion detection is disabled via
OpConfig[BIE=0]. In this case, the gauge does not detect battery insertion from the BIN pin’s logic state, but
relies on the BAT_INSERT host subcommand to indicate battery presence in the system. This subcommand also
starts Impedance Track™ gauging.
BAT_REMOVE: 0X000D
This subcommand forces the Flags() [BAT_DET] bit to clear when the battery insertion detection is disabled via
OpConfig[BIE=0]. In this case, the gauge does not detect battery removal from the BIN pin’s logic state, but
relies on the BAT_REMOVE host subcommand to indicate battery removal from the system.
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SET_FULLSLEEP: 0x0010
Instructs the gas gauge to set the CONTROL_STATUS [FULLSLEEP] bit to 1. This allows 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 the high frequency oscillator circuit used by the communication engines. 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 device back to the SLEEP mode.
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] and [HIBE] 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.
FACTORY_RESTORE: 0X0015
Instructs the fuel gauge to reset learned resistance tables and Qmax values (default = DesignCapacity) to the
default values. This command is only available when the fuel gauge is UNSEALED.
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.
RESET : 0x0041
This command instructs the fuel gauge to perform a full reset. This command is only available when the fuel
gauge is UNSEALED.
Temperature( ): 0x02/0x03
This read-/write-word function returns an unsigned integer value of the temperature in units of 0.1 K measured by
the fuel gauge. If [WRTEMP] bit = 1, a write command sets the temperature to be used for gauging calculations
while a read command returns to temperature previously written. If [WRTEMP] bit = 0, a read command will
return the internal temperature sensor value and write command will be ignored.
Voltage( ): 0x04/0x05
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( ): 0x06/0x07
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
RSVD
RSVD
CHG_INH
RSVD
FC
CHG
Low Byte
OCVTAKEN
RSVD
RSVD
RSVD
BAT_DET
SOC1
SOCF
DSG
OTC =
Over-Temperature in charge condition is detected. True when set. See Over-Temperature Indication: Charge
Sub-Section.
OTD =
Over-Temperature in discharge condition is detected. True when set. See Over-Temperature Indication: Discharge
Sub-Section.
CHG_INH = Charge Inhibit indicates the temperature is outside the range. True when set. See Charge Inhibit Sub-Section.
FC = Full-charged condition reached. True when set.
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CHG = (Fast) charging allowed. True when set.
OCVTAKEN = Cleared on entry to relax mode and Set to 1 when OCV measurement is performed in relax
Battery insertion detected. True when set. When OpConfig[BIE]] is set, [BAT_DET] is set by detecting a logic high to low
BAT_DET = transition at BIN pin. when OpConfig[BIE]] is low, [BAT_DET] is set when host issues BAT_INSERT subcommand and
clear when host issues BAT_REMOVE subcommand.
SOC1 =
If set, RemainingCapacity() = SOC1 Clear Threshold (default = 175mAh).
SOCF =
If set, RemainingCapacity() = SOCF Clear Threshold (default = 100mAh).
DSG = Discharging detected. True when set.
NominalAvailableCapacity( ): 0x08/0x09
This read-only command pair returns the uncompensated (less than C/20 load) battery capacity remaining. Units
are mAh.
FullAvailableCapacity( ): 0x0a/0x0b
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( ): 0x0c/0x0d
This read-only command pair returns the compensated battery capacity remaining. Units are mAh.
FullChargeCapacity( ): 0x0e/0f
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( ): 0x10/0x11
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.
StandbyCurrent( ): 0x12/0x13
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 (default = -10mA), 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 ( = ±5mA) and
is less than or equal to 2 x Initial Standby (default = -10mA). 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.
MaxLoadCurrent( ): 0x14/0x15
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 (default = –500mA) . 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.
AvailableEnergy( ): 0x16/0x17
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.
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AveragePower( ): 0x18/0x19
This read-only function returns an signed integer value of the average power during battery charging and
discharging. 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.
StateOfCharge( ): 0x1c/0x1d
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%.
IntTemperature( ): 0x1e/0x1f
This read-/write-word function returns an unsigned integer value of the internal temperature sensor in units of 0.1
K measured by the fuel gauge. If OpConfig[WRTEMP] = 0, this command will return the same value as
Temperature( ).
StateofHealth( ): 0x20/0x21
0x20 SOH percentage: this read-only function returns an unsigned integer value, expressed as a percentage of
the ratio of predicted FCC(25°C, SOH LoadI) over the DesignCapacity(). The FCC(25°C, SOH LoadI) is the
calculated full charge capacity at 25°C and the SOH LoadI which is programmed in factory (default = –400mA).
The range of the returned SOH percentage is 0x00 to 0x64, indicating 0 to 100% correspondingly.
0x21 SOH Status: this read-only function returns an unsigned integer value, indicating the status of the SOH
percentage. The meanings of the returned value are:
• 0x00: SOH not valid (initialization)
• 0x01: Instant SOH value ready
• 0x02: Initial SOH value ready
– Calculation based on uncompensated Qmax
– Updated at first grid point update after cell insertion
• 0x03: SOH value ready
– Utilize the updated Qmax update
– Calculation based on compensated Qmax
– Updated after complete charge and relax is complete
• 0x04-0xFF: Reserved
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.
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Table 5. Extended Commands
NAME
OperationConfiguration( )
DesignCapacity( )
COMMAND CODE
UNITS
SEALED
ACCESS (1) (2)
UNSEALED
ACCESS (1) (2)
OPCFG
0x3a / 0x3b
N/A
R
R/W
DCAP
0x3c / 0x3d
mAh
R
R/W
0x3e
N/A
N/A
R/W
DataFlashClass( )
(2)
DFCLS
DataFlashBlock( )
(2)
DFBLK
0x3f
N/A
R/W
R/W
DFD
0x40…0x5f
N/A
R
R/W
DFDCKS
0x60
N/A
R/W
R/W
BlockData( )
BlockDataCheckSum( )
BlockDataControl( )
DeviceNameLength( )
DeviceName( )
Reserved
(1)
(2)
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
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.
OperationConfiguration( ): 0x3a/0x3b
SEALED and UNSEALED Access: This command returns the Operation Configuration register setting
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 and is used as an
input for the algorithm to scale the normalized resistance tables.
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.
Issuing a 0x01 instructs the BlockData( ) command to transfer Manufacturer Info Block A.
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.
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. 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.
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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 bq27410 data flash is a non-volatile memory that contains bq27410 initialization, default, cell status,
calibration, configuration, and user information. The data flash can be accessed in several different ways,
depending on what mode the bq27410 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 bq27410 is either in UNSEALED or SEALED modes.
Most data flash locations, however, are only accessible in UNSEALED mode by use of the bq27410 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 bq27410, 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 not resolve the fault.
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ACCESS MODES
The bq27410 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
bq27410 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
Data Flash
Manufacturer Info
FULL ACCESS
R/W
R/W
UNSEALED
R/W
R/W
SEALED
None
R(A)
Although FULL ACCESS and UNSEALED modes appear identical, only FULL ACCESS mode allows the
bq27410 to write access-mode transition keys.
SEALING/UNSEALING DATA FLASH
The bq27410 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 bq27410 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 bq27410, 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.
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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
SubClass
ID
SubClass
Offset
Configuration
34
Charge
2
Charging Voltage
I2
0
4600
4200
mV
Configuration
36
Charge
Termination
0
Taper Current
I2
0
1000
100
mA
Configuration
36
Charge
Termination
4
Taper Voltage
I2
0
1000
100
mV
Configuration
48
Data
13
Cycle Count
U2
0
65535
0
Configuration
48
Data
19
Design Capacity
I2
0
32767
1340
mAh
Configuration
48
Data
21
Design Energy
I2
0
32767
4960
mWh
Configuration
64
Registers
0
Op Config
H1
0x0
0xff
0x19
(flg)
Configuration
64
Registers
3
SOCI Delta
U1
0
100
1
hex
Configuration
68
Power
2
Sleep Current
I2
0
100
10
mA
Configuration
68
Power
11
Hibernate I
U2
0
700
8
mA
Configuration
68
Power
13
Hibernate V
U2
2400
3000
2550
mV
System Data
57
Manufacturer
Info
0-31
Block A 0-31
H1
0x0
0xff
0x0
Gas Gauging
80
IT Cfg
45
Terminate Voltage
I2
2800
3700
3000
Ra Table
91
R_a0
0
Cell0 R_a flag
H2
0x0000
0xffff
0x0055
Ra Table
91
R_a0
2-31
Cell0 R_a 0-14
I2
183
183
102
Ra Table
93
R_a0x
0
xCell0 R_a flag
H2
0x0000
0xffff
0x00ff
Ra Table
93
R_a0x
2-31
xCell0 R_a 0-14
I2
183
183
102
Calibration
104
Data
0
CC Gain
F4
1.00E-01
4.00E+01 0.4768
num
(2^–10Ω)
Calibration
104
Data
4
CC Delta
F4
2.98E+04
1.19E+06 567744.5
68
num
(2^–10Ω)
Calibration
104
Data
8
CC Offset
U2
0
65535
–1200
num (mV)
Calibration
104
Data
10
Board Offset
I1
–128
127
0
num (uV)
Calibration
104
Data
11
Int Temp Offset
I1
–128
127
0
num (°C)
Calibration
104
Data
13
Pack V Offset
I1
–128
127
0
num (mV)
Security
112
Codes
0
Sealed to Unsealed
H4
0x0
0xffffffff
x367204
14
-
Security
112
Codes
4
Unsealed to Full
H4
0x0
0xffffffff
0xffffffff
-
Security
112
Codes
24
FactRestore Key
H4
0x0
0xffffffff
0x00000
000
-
Class
Name
Data
Type
Min
Max
Default
Unit
(EVSW Unit)
(num)
mV
num
num
FUNCTIONAL DESCRIPTION
FUEL GAUGING
The bq27410 is an easy to configure fuel gauge that measures the cell voltage, temperature, and current to
determine battery SOC. The bq27410 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 the Design Capacity. The bq27410 acquires and updates the
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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.
FUEL GAUGING Ra TABLE
Cell0 / xCell0 R_a flag:
The Ra flag indicates the validity of the table data associated with this flag and whether this particular table is
enabled or disabled. The flag should be read only during normal operation.
Each status has one byte and it has the following options:
• 0x00: This means that the table has had a resistance update in the past, but not currently enabled for the cell.
• 0xff: This means that the values in this table are default values. These table resistance values have never
been updated, and is not the currently enabled value for the cell.
• 0x55: This means that this table is enabled for the cell and is in use by the algorithm.
Cell0/xCell0 R_a 0-14:
The Ra Table class has 2 resistance tables, each with 15 values. Each of these values is unitless and is only a
representation of resistance for the associated grid point. When a FACTORY_RESTORE subcommand is
provided, the Ra Table is restored to default resistance to factory condition.
FUEL GAUGING CONFIGURATIONS
The bq27410 features easy to configure data flash to speed-up fuel gauging design. Users are required to
configure Design Capacity, Termination Voltage, and Operation Configuration (see The Operation
Configuration Register section for details) to achieve optimal performance. The Impedance Track™ algorithm
uses these parameters with it’s built-in parameters to achieve accurate battery fuel gauging.
Several built-in parameters are used in the Impedance Track™ algorithm to identify different modes of battery:
• Charging : Chg Current Threshold (default = DesignCapacity /13.3 ),
• Discharging: Dsg Current Threshold (default = DesignCapacity /16.7 )
• Relax: Quit Current Threshold (default = DesignCapacity /25.0 )
To achieve accurate fuel gauging, the bq27410 uses Constant Power Model for fuel gauging. This model uses
the average discharge power from the beginning of the discharge cycle until present time to compute
load-compensated capacity such as RemainingCapacity( ) and FullChargeCapacity( ) in the Impedance Track™
algorithm.
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DETAILED PIN DESCRIPTIONS
The Operation Configuration Register
Two bq27410 pins are configured via the Operation Configuration data flash register, as indicated in Table 8.
This register is programmed/read via the methods described in Section Accessing the Data Flash.
Table 8. Operation Configuration Bit Definition
Default
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
RESCAP
RSVD
BATLOWEN
SLEEP
RMFCC
BIE
GPIO_POL
WRTEMP
0
0
0
1
1
0
0
1
RESCAP = No-load rate of compensation is applied to the reserve capacity calculation. True when set. Default is 0.
RSVD = Reserved for future use.
BATLOWEN =
If set, the BAT_LOW function for GPOUT pin is selected. If cleared, the SOC_INT function is selected for GPOUT.
Default is 0
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.
BIE =
Battery Insertion Enable. If set, the battery insertion is detection via BIN pin input. If cleared, the detection relies on the
host to issue BAT_INSERT subcommand to indicate battery presence in the system. Default is 0.
GPIO_POL = GPOUT pin is active-high if set or active-low if cleared. Default is 0.
WRTEMP = Enables the host to write Temperature( ) if set. If cleared, the internal temperature sensor is used for Temperature( ).
Default is 1.
GPOUT Pin
The GPOUT Pin is a multiplex pin and the polarity of the pin output can be selected via the [GPIO_POL] bit of
the Operation Configuration. The function is defined by [BATLOWEN]. If set, the Battery Low Indicator
(BAT_LOW) function for GPOUT pin is selected. If cleared, the SOC interrupt (SOC_INT) function is selected for
GPOUT.
When the BAT_LOW function is activated, the signaling on the multiplexed pin follows the status of the [SOC1]
bit in the Flags( ) register. The bq27410 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 (factory default = 150mAh), the [SOC1] (State of Charge Initial) flag is set. The
flag is cleared once RemainingCapacity( ) rises above SOC1 Set Threshold (factory default = 175mAh). The
bq27410’s GPOUT pin automatically reflects the status of the [SOC1] flag when OpConfig[BATLOWEN=0].
When RemainingCapacity( ) falls below the second capacity threshold, SOCF Set Threshold (factory default =
75mAh), the [SOCF] (State of Charge Final) flag is set, serving as a final discharge warning. Similarly, when
RemainingCapacity( ) rises above SOCF Clear Threshold (factory default = 100mAh) and the [SOCF] flag has
already been set, the [SOCF] flag is cleared.
When the SOC_INT function is activated, the GPOUT pin generates 1ms pulse width under various conditions as
described in Table 9.
Table 9. SOC_INT Function Definition
SOCI_Delta
Enable Condition
Pulse Width
Description
SOCI_Delta ≠ 0
1ms
During charge, when the StateOfCharge() reaches greater than or equal to (≥) the
defined SOC_INT intervals. The intervals are defined as 100% and 100% – n ×
SOCI_Delta.
During discharge, when the StateOfCharge() reaches less than ( Chg Current Threshold (default = DesignCapacity / 13.3),
then the [OTC] bit of Flags( ) is set. When Temperature() falls to OT Chg Recovery (default = 50°C), the [OTC]
of Flags() is reset.
Over-Temperature Indication: Discharge
If during discharging, Temperature( ) reaches the threshold of OT Dsg (default = 60°C) for a period of OT Dsg
Time (default = 2 seconds) , and AverageCurrent( ) ≤ -Dsg Current Threshold (default = DesignCapacity
/16.7 ) , then the [OTD] bit of Flags( ) is set. When Temperature( ) falls to OT Dsg Recovery (default = 55°C),
the [OTD] bit of Flags( ) is reset.
DETECTING CHARGE TERMINATION
The bq27410 detects charge termination when (1) during 2 consecutive periods of Current Taper Window
(default = 40 seconds), the AverageCurrent( ) is < Taper Current (default = 100 mA), (2) during the same
periods, the accumulated change in capacity > 0.25mAh/ / Current Taper Window (default = 40 seconds), and
(3) Voltage( ) > (Charging Voltage – 100mV) where Charging Voltage = 4200mV by default. 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
The bq27410 can indicate when battery temperature has fallen below or risen above predefined thresholds
Charge Inhibit Temp Low (default = 0˚C) or Charge Inhibit Temp High (default = 45˚C), 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 Temp Low, Charge Temp High] (default = [5˚C,40˚C]).
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POWER MODES
The bq27410 has different power modes: INITIALIZATION, NORMAL, SLEEP, FULLSLEEP and HIBERNATE.
Following Power On Reset (POR), the fuel gauge begins INITIALIZATION. In NORMAL mode, the bq27410 is
fully powered and can execute any allowable task. In SLEEP mode both low frequency and high frequency
oscillators are active. Although the SLEEP has higher current consumption than the FULLSLEEP mode, it is also
a reduced power mode. In FULLSLEEP mode the fuel gauge turns off the high frequency oscillator and 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 or certain I/O activity.
POR
INITIALIZATION
Check for battery insertion
No gauging .
.
Flags [BAT _ DET ] = 0
I CC = Normal
Entry to NORMAL
Flags [ BAT _ DET ] = 1
Exit From HIBERNATE
V CELL < POR threshold
Exit From
NORMAL
Flags [BAT _ DET ] = 0
NORMAL
Exit From HIBERNATE
Communication Activity
OR
bq27410 clears Control Status
[HIBERNATE ] = 0
Recommend Host also set Control
Status [HIBERNATE ] = 0
Fuel gauging and data
updated every 1s
Exit From SLEEP /FULLSLEEP
Pack Configuration
[SLEEP ] = 0
OR
| AverageCurrent ( ) | > Sleep Current
OR
Current is Detected above I
WAKE
ICC = Normal
SLEEP
HIBERNATE
Wakeup From HIBERNATE
Communication to gauge
AND
Comm address is NOT for bq27410
Disable all subcircuits
except GPIO .
Entry to SLEEP
Pack Configuration
[SLEEP ] = 1
AND
| AverageCurrent ( ) | = Sleep Current
Fuel gauging and data
updated every 20 seconds
I CC = Sleep
I CC = Hibernate
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
OR
V CELL
Cell relaxed
AND
< Hibernate Voltage
Entry to FULLSLEEP
Host must set Control Status
[FULLSLEEP ] = 1
FULL SLEEP
WAIT _HIBERNATE
Fuel gauging and data
updated every 20 seconds
In low power state of SLEEP
mode . Gas gauging and data
updated every 20 seconds
Exit From SLEEP
( Host has set Control Status
[HIBERNATE ] = 1
OR
VCELL < Hibernate Voltage
ICC = Full Sleep
I CC = Sleep /FullSleep
System Shutdown
Exit From FULLSLEEP
Any Communication Cmd
System Sleep
Figure 2. Power Mode Diagram
INITIALIZATION Mode
Following Power On Reset (POR), the fuel gauge begins INITIALIZATION mode where essential data is
initialized and will remain in INITIALIZATION mode as halted-CPU state when an adapter, or other power source
is present to power the bq27410 (and system), yet no battery has been detected. Until battery insertion is
detected, the fuel gauge cannot transition to other power mode. When battery insertion is detected, a series of
initialization activities begin including an OCV measurement. In addition CONTROL_STATUS[QMAXU] and
[RESU] bits are cleared to allow fast learning of Qmax and impedance.
Some commands, issued by a system processor, can be processed while the bq27410 is halted in this mode.
The gauge will wake up to process the command, and then return to the halted state awaiting battery insertion.
The current consumption of INITIALIZATION mode is similar to NORMAL mode.
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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 (Operation Configuration [SLEEP]) = 1) and
AverageCurrent( ) is below the programmable level Sleep Current (default = 10mA). Once entry into SLEEP
mode has been qualified, but prior to entering it, the bq27410 performs an ADC autocalibration to minimize
offset.
During SLEEP mode, the bq27410 periodically takes data measurements and updates its data set. However, a
majority of its time is spent in an idle condition.
The bq27410 exits SLEEP if any entry condition is broken, specifically when: AverageCurrent( ) rises above
Sleep Current (default = 10mA).
FULLSLEEP Mode
FULLSLEEP mode is entered automatically if the feature is enabled by setting the [FULLSLEEP] bit in the
Control Status register when the BQ27410 is in SLEEP mode. The gauge exits the FULLSLEEP and returns to
SLEEP mode when there is communication to the gauge. The bq27410 can also exit FULLSLEEP and returns to
NORMAL if any SLEEP mode entry condition is broken, specifically when AverageCurrent( ) rises above Sleep
Current is detected. 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 oscillator is turned off. The power consumption is further reduced in this mode
compared to the SLEEP mode.
During FULLSLEEP mode, the BQ27410 periodically takes data measurements and updates its data set.
However, a majority of its time is spent in an idle condition.
While in FULLSLEEP mode, the fuel gauge can suspend serial communications as much as 4ms by holding the
communication line(s) low. This delay is necessary to correctly process host communication, since the fuel
gauge processor is mostly halted in FULLSLEEP mode.
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 the system’s responsibility to wake the bq27410 after it has gone into HIBERNATE mode and prevents a
charger from charging the battery before the [OCVTAKEN] bit is set which signals an OCV reading is taken. After
waking, the gauge can proceed with the initialization of the battery information.
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COMMUNICATIONS
I2C INTERFACE
The bq27410 supports the standard I2C read, incremental read, quick read, one byte write, and incremental write
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 will therefore be 0xAA or 0xAB for write or read, respectively.
Host generated
S
ADDR[6:0]
0 A
bq27410 generated
CMD[7:0]
A
DATA [7:0]
A P
S
ADDR[6:0]
(a) 1-byte write
S
ADDR[6:0]
0 A
1 A
DATA [7:0]
N P
(b) quick read
CMD[7:0]
A Sr
ADDR[6:0]
1 A
DATA [7:0]
N P
(c) 1- byte read
S
ADDR[6:0]
0 A
CMD[7:0]
A Sr
ADDR[6:0]
1 A
DATA [7:0]
A ...
DATA [7:0]
N P
(d) incremental read
S
ADDR[6:0]
0 A
CMD[7:0]
A
DATA [7:0]
A
DATA [7:0]
A
...
A P
(e) incremental write
(S = Start, Sr = Repeated Start, A = Acknowledge, N = No Acknowledge, and P = Stop).
Figure 3. 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 bq27410 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).
The following command sequences are not supported:
Attempt to write a read-only address (NACK after data sent by master):
S
ADDR[6:0]
0
A
CMD[7:0]
A
DATA[7:0]
N
P
Attempt to read an address above 0x6B (NACK command):
S
ADDR[6:0]
0
A
CMD[7:0]
N P
I2C TIME OUT
The I2C engine will release both SDA and SCL if the I2C bus is held low for about 2 seconds. If the bq27410 was
holding the lines, releasing them will free for the master to drive the lines. If an external condition is holding either
of the lines low, the I2C engine will enter the low power sleep mode. 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 checksum and OCV commands. A 100ms waiting
time is required between the checksum command and reading result, and a 1.2 second waiting time is required
between the OCV command and result. For read-write standard command, a minimum of 2 seconds is required
to get the result updated. For read-only standard commands, there is no waiting time required, but the host
should not issue all standard commands more than two times per second. Otherwise, the gauge could result in a
reset issue due to the expiration of the watchdog timer.
The I2C clock stretch could happen in a typical application. A maximum 80ms clock stretch could be observed
during the flash updates.
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COMMUNICATIONS (continued)
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bq27410-G1
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Optional Pull up
1.8 MW
REFERENCE SCHEMATIC
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PACKAGE OPTION ADDENDUM
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10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
BQ27410DRZR-G1
ACTIVE
SON
DRZ
12
2500
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BQ
7410
BQ27410DRZT-G1
ACTIVE
SON
DRZ
12
250
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BQ
7410
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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