bq27620-G1
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SLUSAE3 – OCTOBER 2012
System-Side Impedance Track™ Fuel Gauge with Dynamic Voltage Correlation
Check for Samples: bq27620-G1
1 INTRODUCTION
1.1
FEATURES
1.2
• Battery Fuel Gauge for 1-Series Li-Ion
applications based on Patented Impedance
Track™ Technology with Dynamic Voltage
Correlation (IT-DVC)
• Resides on System Main Board
• No Sense Resistor Required
• Powered directly from battery with integrated
LDO
• Supports embedded or removable Battery
Packs
• System Side Fuel-Gauge Provides:
– Accurate Battery Fuel Gauging; models the
Battery Discharge Curve for Accurate Timeto-Empty Predictions
– Automatically Adjusts for Battery Aging,
Battery Self-Discharge, and
Temperature/Rate Inefficiencies
– Internal Temperature Sensor for Battery
Temperature Reporting
– Battery Low Interrupt Warning
– Battery Insertion Indicator
– Configurable Level of State of Charge (SOC)
Interrupts
– State of Health Indicator
– 32 Bytes of Non-Volatile Scratch-Pad FLASH
• 400-kHz I2C™ Interface for Connection to
System Microcontroller Port
• In a 15-Pin NanoFree™ (CSP) Packaging
•
•
•
•
123
APPLICATIONS
Smartphones
Digital Still and Video Cameras
Handheld Terminals
MP3 or Multimedia Players
1.3
DESCRIPTION
The Texas Instruments bq27620-G1 system-side is
an easy configure microcontroller peripheral that
provides fuel gauging for single-cell Li-Ion battery
packs. The device requires minimal user
configuration and system microcontroller firmware
development.
The bq27620-G1 uses the patented Impedance
Track™ algorithm with Dynamic Voltage Correlation
for fuel gauging. This patented process eliminates the
need for a sense resistor when calculating
remaining battery capacity (mAh), state-of-charge
(%), run-time to empty (min), battery voltage (mV),
temperature (°C) and state of health (%).
Battery fuel gauging with the bq27620-G1 requires
connections only to PACK+ (P+), PACK– (P–), and
Thermistor (T) connections to a removable battery
pack or embedded battery circuit. The CSP option is
a 15-ball package in the nominal dimensions of 2610
× 1956 µm with 0,5 mm lead pitch. It is ideal for
space constrained applications.
TYPICAL APPLICATION
Host System
Single Cell Li-lon
Battery Pack
VCC
LDO
CE
Power
Management
Controller
I2C
PACK+
Battery
Low
Voltage
Sense
DATA
Temp
Sense
PROTECTION
IC
T
bq27620
BAT_GD
PACK-
FETs
CHG
DSG
SOC_INT
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, NanoFree are trademarks of Texas Instruments.
I2C is a trademark of NXP B.V. Corp Netherlands.
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 © 2012, Texas Instruments Incorporated
bq27620-G1
SLUSAE3 – OCTOBER 2012
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.
1
2
3
INTRODUCTION
.........................................
..........................................
1.2
APPLICATIONS .....................................
1.3
DESCRIPTION ......................................
DEVICE INFORMATION ................................
2.1
AVAILABLE OPTIONS ..............................
2.2
THERMAL INFORMATION ..........................
1
1.1
1
2.3
PIN ASSIGNMENT AND PACKAGE DIMENSIONS
4
ELECTRICAL SPECIFICATIONS
.....................
..................
RECOMMENDED OPERATING CONDITIONS .....
SUPPLY CURRENT .................................
5
3.1
5
FEATURES
ABSOLUTE MAXIMUM RATINGS
3.2
3.3
3.4
.................................
2.5V LDO REGULATOR .............................
INTERNAL CLOCK OSCILLATORS ................
POWER-ON RESET
3.6
3.7
3.8
ADC (TEMPERATURE AND CELL
MEASUREMENT) CHARACTERISTICS
3.9
3.10
2
5.6
34
CHARGING AND CHARGE-TERMINATION
INDICATION ........................................ 34
5.7
POWER MODES
1
3
3
5
3
6
6
7
............
7
............................. 9
................................ 10
DATA COMMANDS
DATA FLASH INTERFACE
19
4.3
MANUFACTURER INFORMATION BLOCK
20
8
...................................
.........
APPLICATION-SPECIFIC INFORMATION
6.1
6
6
DATA FLASH MEMORY CHARACTERISTICS ..... 8
I2C-COMPATIBLE INTERFACE COMMUNICATION
TIMING CHARACTERISTICS ....................... 8
GENERAL DESCRIPTION
4.1
5
1
DIGITAL INPUT AND OUTPUT DC
CHARACTERISTICS ................................ 6
3.5
4
5
........................
.......
4.4
ACCESS MODES ..................................
4.5
SEALING/UNSEALING DATA FLASH .............
4.6
DATA FLASH SUMMARY ..........................
FUNCTIONAL DESCRIPTION ........................
5.1
FUEL GAUGING ...................................
5.2
IMPEDANCE TRACK™ VARIABLES ..............
5.3
DETAILED PIN DESCRIPTION ....................
5.4
TEMPERATURE MEASUREMENT ................
5.5
OVERTEMPERATURE INDICATION ..............
4.2
21
21
22
26
26
27
29
34
35
36
BATTERY PROFILE STORAGE AND SELECTION
......................................................
...................................
7.1
I2C INTERFACE ....................................
7.2
I2C Time Out .......................................
7.3
I2C Command Waiting Time ........................
7.4
I2C Clock Stretching ................................
REFERENCE SCHEMATICS .........................
8.1
SCHEMATIC ........................................
COMMUNICATIONS
Contents
36
37
37
37
38
38
39
39
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2 DEVICE INFORMATION
2.1
AVAILABLE OPTIONS
PART NUMBER
bq27620YZFR-G1
bq27620YZFT-G1
(1)
FIRMWARE
VERSION (1)
PACKAGE (1)
TA
COMMUNICATION FORMAT
1.06
(0x106)
CSP-15
–40°C to 85°C
I2C
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.
2.2
THERMAL INFORMATION
THERMAL METRIC (1)
bq27620-G1
YZF(15 PINS)
θJA
Junction-to-ambient thermal resistance
70
θJCtop
Junction-to-case (top) thermal resistance
17
θJB
Junction-to-board thermal resistance
20
ψJT
Junction-to-top characterization parameter
1
ψJB
Junction-to-board characterization parameter
18
Junction-to-case (bottom) thermal resistance
n/a
θJCbot
(1)
TAPE and REEL
QUANTITY
UNITS
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953
DEVICE INFORMATION
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2.3
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PIN ASSIGNMENT AND PACKAGE DIMENSIONS
(TOP VIEW)
(BOTTOM VIEW)
B3
C3
D3
E3
E3
D3
C3
B3
A3
A2
B2
C2
D2
E2
E2
D2
C2
B2
A2
A1
B1
C1
D1
E1
E1
D1
C1
B1
A1
A3
E
xx
xx
Pin A1
Index Area
D
DIM
MIN
TYP
MAX
D
2580
2610
2640
E
1926
1956
1986
UNITS
m
Table 2-1. PIN FUNCTIONS
PIN
NAME
NO.
TYPE (1)
DESCRIPTION
VSS
A1, B1,
C1, C2
P
Device ground
VCC
D1
P
Regulator output and bq27620-G1 processor power. Decouple with 1μF ceramic capacitor to Vss.
REGIN
E1
P
Regulator input. Decouple with 0.1μF ceramic capacitor to Vss.
SOC_INT
A2
O
SOC state interrupts output. Generates a pulse under the conditions specified by Table 5-7. Open drain output. (RA3)
BAT_GD
B2
O
Battery-good indicator. Active-low by default, though polarity can be configured through the [BATG_POL] bit of
Operation Configuration. Push-pull output. (RC1)
CE
D2
I
Chip Enable. Internal LDO is disconnected from REGIN when driven low.
BAT
E2
I
Cell-voltage measurement input. ADC input. Recommend 4.8V maximum for conversion accuracy. (RC3)
SCL
A3
I
Slave I2C serial communications clock input line for communication with system (Master). Use with 10kΩ pull-up
resistor (typical). (RA2)
SDA
B3
I/O
Slave I2C serial communications data line for communication with system (Master). Open-drain I/O. Use with 10kΩ
pull-up resistor (typical). (RA1)
BAT_LOW
C3
O
Battery Low output indicator. Active high by default, though polarity can be configured through the [BATL_POL] bit of
Operation Configuration. Push-pull output. (RC0)
TS
D3
IA
Pack thermistor voltage sense (use 103AT-type thermistor). ADC input. (RC2)
BI/TOUT
E3
I/O
Battery-insertion detection input. Power pin for pack thermistor network. Thermistor-multiplexer control pin. Use with
pull-up resistor >1MΩ (1.8 MΩ typical). (RA0)
(1)
4
I/O = Digital input/output, IA = Analog input, P = Power connection
DEVICE INFORMATION
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3 ELECTRICAL SPECIFICATIONS
3.1
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range (unless otherwise noted) (1)
PARAMETER
VREGIN
VALUE
Regulator input range
UNIT
–0.3 to 5.5
–0.3 to 6.0
V
(2)
V
VCC
Supply voltage range
–0.3 to 2.75
V
VIOD
Open-drain I/O pins (SDA, SCL, SOC_INT )
–0.3 to 5.5
V
VBAT
BAT input pin
–0.3 to 5.5
V
–0.3 to 6.0
VI
Input voltage range to all other pins ( BI/TOUT , TS , BAT_GD )
ESD
(2)
V
–0.3 to VCC + 0.3
Human-body model (HBM), BAT pin
V
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)
(2)
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Condition not to exceed 100 hours at 25 °C lifetime.
3.2
RECOMMENDED OPERATING CONDITIONS
TA = -40°C to 85°C, VREGIN = VBAT = 3.6V (unless otherwise noted)
PARAMETER
VREGIN
Supply voltage
CREGIN
External input capacitor for internal
LDO between REGIN and VSS
CLDO25
External output capacitor for internal
LDO between VCC and VSS
tPUCD
Power-up communication delay
3.3
TEST CONDITIONS
No operating restrictions
No FLASH writes
Nominal capacitor values specified.
Recommend a 5% ceramic X5R type
capacitor located close to the device.
MIN
TYP
MAX
2.8
4.5
2.45
2.8
0.47
UNIT
V
0.1
μF
1
μF
250
ms
SUPPLY CURRENT
TA = 25°C and VREGIN = VBAT = 3.6V (unless otherwise noted)
PARAMETER
TEST CONDITIONS
ICC
Normal operating-mode
current (1)
Fuel gauge in NORMAL mode.
ILOAD > Sleep Current
ISLP
Low-power storage-mode
current (1)
Fuel gauge in SLEEP mode.
ILOAD < Sleep Current
IHIB
Hibernate operating-mode
current (1)
Fuel gauge in HIBERNATE mode.
ILOAD < Hibernate Current
(1)
MIN
TYP
MAX
UNIT
118
μA
23
μA
8
μA
Specified by design. Not production tested.
ELECTRICAL SPECIFICATIONS
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3.4
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DIGITAL INPUT AND OUTPUT DC CHARACTERISTICS
TA = –40°C to 85°C, typical values at TA = 25°C and VREGIN = 3.6 V (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
VOL
Output voltage, low (SCL, SDA,
SOC_INT , BAT_LOW ,
BAT_GD )
IOL = 3 mA
VOH(PP)
Output voltage, high
(BAT_LOW , BAT_GD )
IOH = –1 mA
VCC –
0.5
VOH(OD)
Output voltage, high (SDA,
SCL, SOC_INT )
External pullup resistor connected to
VCC
VCC –
0.5
Input voltage, low (SDA, SCL
pins)
VIL
Input voltage, low ( BI/TOUT
pin)
Input voltage, high ( BI/TOUT
pin)
VIL(CE)
0.4
Input voltage, high (CE pin)
Ilkg
Input leakage current (I/O pins)
UNIT
V
V
0.6
V
BAT INSERT CHECK MODE active
–0.3
0.6
1.2
BAT INSERT CHECK MODE active
VCC +
0.3
1.2
Input voltage, low (CE pin)
VIH(CE)
(1)
MAX
–0.3
Input voltage, high (SDA, SCL
pins)
VIH
TYP
V
0.8
VREGIN = 2.8 to 4.5V
V
VREGIN –
0.5
0.3
(1)
μA
Specified by design. Not production tested.
3.5
POWER-ON RESET
TA = –40°C to 85°C, typical values at TA = 25°C and VREGIN = 3.6 V (unless otherwise noted)
PARAMETER
VIT+
Positive-going battery voltage
input at VCC
VHYS
Power-on reset hysteresis
3.6
TEST CONDITIONS
MIN
TYP
MAX
UNIT
2.05
2.15
2.20
V
45
115
185
mV
UNIT
2.5V LDO REGULATOR
TA = –40°C to 85°C, CLDO25 = 1μF, VREGIN = 3.6V (unless otherwise noted)
PARAMETER
VREG25
3.7
Regulator output voltage
MIN
NOM
MAX
2.8V ≤ VREGIN ≤ 4.5V, IOUT ≤ 16mA
TEST CONDITION
2.3
2.5
2.6
2.45V ≤ VREGIN < 2.8V (low battery),
IOUT ≤ 3mA
2.3
V
V
INTERNAL CLOCK OSCILLATORS
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
fOSC
High Frequency Oscillator
2.097
MHz
fLOSC
Low Frequency Oscillator
32.768
kHz
6
ELECTRICAL SPECIFICATIONS
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3.8
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ADC (TEMPERATURE AND CELL MEASUREMENT) CHARACTERISTICS
TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
VA1
Input voltage range (TS )
VSS –
0.125
2
V
VA2
Input voltage range (BAT)
VSS –
0.125
5
V
VIN(ADC)
Input voltage range
GTEMP
Internal temperature sensor
voltage gain
tADC_CONV
Conversion time
0.05
Resolution
14
VOS(ADC)
Input offset
ZADC1
Effective input resistance
(TS ) (1)
ZADC2
Effective input resistance
(BAT) (1)
Ilkg(ADC)
(1)
Input leakage current
1
–2
V
mV/°C
125
ms
15
bits
1
bq27620-G1 not measuring cell
voltage
bq27620-G1 measuring cell voltage
(1)
mV
8
MΩ
8
MΩ
100
kΩ
0.3
μA
Specified by design. Not tested in production.
ELECTRICAL SPECIFICATIONS
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3.9
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DATA FLASH MEMORY CHARACTERISTICS
TA = –40°C to 85°C, 2.4 V < VCC < 2.6 V; typical values at TA = 25°C and VCC = 2.5 V (unless otherwise noted)
PARAMETER
tDR
Data retention
TEST CONDITIONS
(1)
Flash-programming write
cycles (1)
tWORDPROG
MIN
TYP
MAX
UNIT
10
Years
20,000
Cycles
Word programming time (1)
(1)
ms
10
mA
ICCPROG
Flash-write supply current
tDFERASE
Data flash master erase time (1)
200
ms
tIFERASE
Instruction flash master erase
time (1)
200
ms
tPGERASE
Flash page erase time (1)
20
ms
(1)
5
2
Specified by design. Not production tested
I2C-COMPATIBLE INTERFACE COMMUNICATION TIMING CHARACTERISTICS
3.10
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)
MAX
UNIT
tr
SCL/SDA rise time
PARAMETER
300
ns
tf
SCL/SDA fall time
300
ns
tw(H)
SCL pulse duration (high)
600
ns
tw(L)
SCL pulse duration (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
t(BUF)
Bus free time between stop and
start
66
μs
fSCL
Clock frequency
(1)
TEST CONDITIONS
MIN
(1)
TYP
400
kHz
If the clock frequency (fSCL) is > 100 kHz, use 1-byte write commands for proper operation. All other transactions types are supported at
400 kHz. (Refer to Section 7.1 and Section 7.3)
Figure 3-1. I2C-Compatible Interface Timing Diagrams
8
ELECTRICAL SPECIFICATIONS
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4 GENERAL DESCRIPTION
The bq27620-G1 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 time-to-empty (TTE), time-to-full (TTF) and state-of-charge (SOC) as well as SOC interrupt signal to the
host.
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 device control and status
registers, as well as its data flash locations. Commands are sent from system to gauge using the
bq27620-G1’s I2C serial communications engine, and can be executed during application development,
system manufacture, or end-equipment operation.
Cell information is stored in the device in non-volatile flash memory. Many of these data flash locations are
accessible during application development. They cannot, generally, be accessed directly during endequipment operation. Access to these locations is achieved by either use of the bq27620-G1’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 bq27620-G1 provides a 32-byte user-programmable data flash Manufacturer Info Block. This data
space is accessed through a data flash interface. For specifics on accessing the data flash,
MANUFACTURER INFORMATION BLOCKS.
The key to the bq27620-G1’s high-accuracy gas gauging prediction is Texas Instrument’s proprietary
Impedance Track™ algorithm with Dynamic Voltage Correlation (IT-DVC). This algorithm uses cell
measurements, characteristics, and properties to create state-of-charge predictions that can achieve less
than 5% error across a wide variety of operating conditions and over the lifetime of the battery.
The device utilizes a comprehensive battery model to estimate the average current in real time,
eliminating the need of a sense resistor. When a cell is attached to the device, cell impedance is
computed, open-circuit voltage (OCV), and cell voltage under loading conditions.
The device external temperature sensing is optimized with the use of a high accuracy negative
temperature coefficient (NTC) thermistor with R25 = 10.0kΩ ±1%. B25/85 = 3435K ± 1% (such as Semitec
NTC 103AT). The bq27620-G1 can also be configured to use its internal temperature sensor. When an
external themistor is used, a 18.2k pull up resistor between BT/TOUT and TS pins is also required. The
bq27620-G1 uses temperature to monitor the battery-pack environment, which is used for fuel gauging
and cell protection functionality.
To minimize power consumption, the device has different power modes: NORMAL, SLEEP, HIBERNATE,
and BAT INSERT CHECK. The bq27620-G1 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 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: 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.
GENERAL DESCRIPTION
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DATA COMMANDS
4.1.1
STANDARD DATA COMMANDS
The bq27620-G1 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 4-1. 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 of
Communication. Read/Write permissions depend on the active access mode, SEALED or UNSEALED
(for details on the SEALED and UNSEALED states, see Section 4.4 , Access Modes.)
Table 4-1. Standard Commands
NAME
Control( )
CNTL
AtRate( )
AtRateTimeToEmpty( )
COMMAND CODE
UNITS
SEALED
ACCESS
0x00 / 0x01
N/A
R/W
0x02 / 0x03
mA
R/W
0x04 / 0x05
Minutes
R
Temperature( )
TEMP
0x06 / 0x07
0.1 K
R/W
Voltage( )
VOLT
0x08 / 0x09
mV
R
FLAGS
Flags( )
0x0a / 0x0b
N/A
R
NominalAvailableCapacity( )
0x0c / 0x0d
mAh
R
FullAvailableCapacity( )
0x0e / 0x0f
mAh
R
RemainingCapacity( )
RM
0x10 / 0x11
mAh
R
FullChargeCapacity( )
FCC
0x12 / 0x13
mAh
R
EffectiveCurrent( )
0x14 / 0x15
mA
R
TimeToEmpty( )
0x16 / 0x17
Minutes
R
TimeToFull( )
0x18 / 0x19
Minutes
R
StandbyCurrent( )
0x1a / 0x1b
mA
R
StandbyTimeToEmpty( )
0x1c / 0x1d
Minutes
R
MaxLoadCurrent( )
0x1e / 0x1f
mA
R
MaxLoadTimeToEmpty( )
0x20 / 0x21
Minutes
R
AvailableEnergy( )
0x22 / 0x23
mWh
R
AveragePower( )
0x24 / 0x25
mW
R
0x26 / 0x27
Minutes
R
0x28 / 0x29
% / num
R
0x2A / 0x2B
num
R
TTEatConstantPower( )
StateOfHealth( )
SOH
CycleCount( )
StateOfCharge( )
0x2c / 0x2d
%
R
InternalTemperature( )
0x36 / 0x37
0.1 K
R
OperationConfiguration( )
0x3A / 0x3B
N/A
R
ApplicationStatus()
0x6A / 0x6B
N/A
R
10
SOC
GENERAL DESCRIPTION
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4.1.1.1
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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 bq27620-G1 during normal operation and additional features when the device is in different
access modes, as described in Table 4-2.
Table 4-2. Control( ) Subcommands
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 in hex digits. (type = 0x0620)
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
Yes
Returns previous MAC subcommand code
CHEM_ID
0x0008
Yes
Reports the chemical identifier of the Impedance Track™ configuration
OCV_CMD
0x000c
Yes
Request the gauge to take a OCV measurement
BAT_INSERT
0x000d
Yes
Forces the BAT_DET bit set when the [BIE] bit is 0
BAT_REMOVE
0x000e
Yes
Forces the BAT_DET bit clear when the [BIE] bit is 0
SET_HIBERNATE
0x0011
Yes
Forces CONTROL_STATUS [HIBERNATE] to 1
CLEAR_HIBERNATE
0x0012
Yes
Forces CONTROL_STATUS [HIBERNATE] to 0
DF_VERSION
0x001F
Yes
Returns the Data Flash Version code
SEALED
0x0020
No
Places the bq27620-G1 in SEALED access mode
OPTIMIZ
0x0030
No
Sets the OPTIMIZ bit and enables the optimization cycle
RESET
0x0041
No
Forces a full reset of the bq27620-G1
CNTL FUNCTION
DESCRIPTION
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4.1.1.1.1 CONTROL_STATUS: 0x0000
Instructs the fuel gauge to return status information to control addresses 0x00/0x01. The status word
includes the following information.
Table 4-3. CONTROL_STATUS Bit Definitions
High byte
Low byte
bit7
INITCOMP
bit6
FAS
HIBERNATE
bit5
SS
RLearn
bit4
RSVD
SLEEP
bit3
LDMD
bit2
RUP_DIS
bit1
OCVCMDCOMP
VOK
bit0
OCVFAIL
OPTMIZ
FAS = Status bit indicating the bq27620-G1 is in FULL ACCESS SEALED state. Active when set.
SS = Status bit indicating the bq27620-G1 is in SEALED state. Active when set.
OCVCMDCOMP = Status bit indicating the bq27620-G1 has executed the OCV command. This bit can only be set with battery’s presence.
True when set.
OCVFAIL = Status bit indicating bq27620-G1 OCV reading is failed due to the current. This bit can only be set with battery’s presence. True
when set.
INITCOMP = Initialization completion bit indicating the initialization completed. This bit can only be set with battery’s presence. True when
set.
HIBERNATE = Status bit indicating a request for entry into HIBERNATE from SLEEP mode. True when set. Default is 0.
RLean = Indicates that resistance has been learned. True when set.
LDMD = Status bit indicating the bq27620-G1 Impedance Track™ algorithm is using constant-power mode. True when set. Default is 0
(constant-current mode).
RUP_DIS = Status bit indicating the bq27620-G1 Ra table updates are disabled. Updates disabled when set.
VOK = Status bit indicating that a relaxed OCV measurement has occurred, always clears at the onset of charge or discharge currents.
True when set.
OPTMIZ = Status bit indicating the bq27620-G1 is in an optimization mode; when set the gauge is in its optimization mode of operation for
determining Qmax. True when set.
4.1.1.1.2 DEVICE_TYPE: 0x0001
Instructs the fuel gauge to return the device type to addresses 0x00/0x01.
4.1.1.1.3 FW_VERSION: 0x0002
Instructs the fuel gauge to return the firmware version to addresses 0x00/0x01. Refer to Available Options
for the expected data value.
4.1.1.1.4 HW_VERSION: 0x0003
Instructs the fuel gauge to return the hardware version to addresses 0x00/0x01.
4.1.1.1.5 PREV_MACWRITE: 0x0007
Instructs the fuel gauge to return the previous subcommand written to addresses 0x00/0x01. Note: This
subcommand is only supported for previous subcommand codes 0x0000 through 0x0014. For
subcommand codes greater than 0x0009, a value of 0x0007 is returned.
4.1.1.1.6 CHEM_ID: 0x0008
Instructs the fuel gauge to return the chemical identifier for the Impedance Track™ configuration to
addresses 0x00/0x01.
4.1.1.1.7 OCV CMD: 0X000C
This command is to request the gauge to take a OCV reading. This command can only be issued after the
[INICOMP] has been set, indicating the initialization has been completed. The OCV measurement take
place at the beginning of the next repeated 1s firmware synchronization clock. During the same time
period, the SOC_INT will pulse. The host should use this signal to reduce the load current below the C/20
in 8ms for a valid OCV reading. The OCV command [OCVFAIL] bit will be set if the OCV_CMD is issued
when [CHG_INH] is set.
12
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4.1.1.1.8 BAT_INSERT: 0X000D
This command is to force the BAT_DET bit to be set when the battery insertion detection is disabled.
When the BIE is set to 0, the battery insertion detection is disabled. The gauge relies on the host to inform
the battery insertion with this command to set the BAT_DET bit.
4.1.1.1.9 BAT_REMOVE: 0X000E
This command is to force the BAT_DET bit to be clear when the battery insertion detection is disabled.
When the BIE is set to 0, the battery insertion detection is disabled. The gauge relies on the host to inform
it of the battery removal with this command to clear the BAT_DET bit.
4.1.1.1.10 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.
4.1.1.1.11 CLEAR_HIBERNATE: 0x0012
Instructs the fuel gauge to force the CONTROL_STATUS [HIBERNATE] bit to 0. This prevents the gauge
from entering the HIBERNATE power mode after the transition to the SLEEP power state is detected. It
can also be used to force the gauge out of HIBERNATE mode.
4.1.1.1.12 DF_VERSION: 0x001F
Instructs the fuel gauge to return the 16-bit data flash revision code to addresses 0x00/0x01. The code is
stored inData Flash Version and provides a simple method for the customer to control data flash
revisions. The default DF_VERSION is 0x0000.
4.1.1.1.13 SEALED: 0x0020
Instructs the fuel gauge to transition from the UNSEALED state to the SEALED state. The fuel gauge must
always be set to the SEALED state for use in end equipment.
4.1.1.1.14 OPTIMIZ: 0x0030
This MAC command should be issued at the end of full charge cycle before the full discharge cycle
begins. This command will set bit 0 (OPTMIZ) of the Control/Status register. When the bit is set and the
gauge detects discharge it will stop using estimated current for Q measurement. Instead it will use
DataFlash IT.LearnCurrent and accumulate charge using that current until discharge termination is
detected from the current estimation engine. At that point the current used by the gauge defaults to zero
mA. This command is only available when the fuel gauge is UNSEALED.
4.1.1.1.15 RESET: 0x0041
This command instructs the fuel gauge to perform a full reset. This command is only available when the
fuel gauge is UNSEALED.
4.1.1.2
AtRateTimeToEmpty( ): 0x04/0x05
This read-word function returns an unsigned integer value of the predicted remaining operating time if the
battery is discharged at the AtRate( ) value in minutes with a range of 0 to 65,534. A value of 65,535
indicates AtRate( ) = 0. The fuel gauge updates AtRateTimeToEmpty( ) within 1 s after the system sets the
AtRate( ) value. The fuel gauge automatically updates AtRateTimeToEmpty( ) based on the AtRate( )
value every 1 s. Both the AtRate( ) and AtRateTimeToEmpty( ) commands must only be used in NORMAL
mode.
GENERAL DESCRIPTION
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Temperature( ): 0x06/0x07
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
and [TEMPS] bit = 0, a read command will return the internal temperature sensor value.
4.1.1.4
Voltage( ): 0x08/0x09
This read-word function returns an unsigned integer value of the measured cell-pack voltage in mV with a
range of 0 to 6000 mV.
4.1.1.5
Flags( ): 0x0a/0x0b
This read-word function returns the contents of the fuel-gauge status register, depicting the current
operating status.
Table 4-4. Flags Bit Definitions
High byte
Low byte
bit7
OTC
–
bit6
OTD
–
bit5
–
OCVGD
bit4
CALEN
NEEDID
bit3
CHG_INH
BATTDET
bit2
XCHG
SOC1
bit1
FC
SYSDOWN
bit0
CHG
DSG
OTC = Overtemperature in charge condition is detected. True when set. SOC_INT will toggle once if set.
OTD = Overtemperature in discharge condition is detected. True when set. SOC_INT will toggle once if set.
CALEN = Status bit indicating the calibration function is enabled. True when set.
CHG_INH = Charge inhibit: unable to begin charging (temperature outside the range [Charge Inhibit Temp Low, Charge Inhibit Temp
High]). True when set.
XCHG = Charge suspend alert (temperature outside the range [Suspend Temperature Low, Suspend Temperature High]). True when
set.
FC = Full-charged condition reached. Set when charge termination condition is met. (RMFCC=1; Set FC_Set % = -1% when RMFCC = 0).
True when set
CHG = (Fast) charging allowed. True when set.
OCVGD = Good OCV measurement taken. True when set.
NEEDID = Waiting to identify inserted battery. True when set.
BATTDET = Battery detected. True when set.
SOC1 = State-of-charge threshold 1 (SOC1 Set) reached. The flag is enabled when BL_INT bit in Operation Configuration B is set. True
when set.
SysDown = SystemDown bit indicating the system shut down. SOC_INT will toggle once if set.
DSG = Discharging detected. True when set.
4.1.1.6
NominalAvailableCapacity( ): 0x0c/0x0d
This read-only command pair returns the uncompensated (less than C/20 load) battery capacity
remaining. Units are mAh.
4.1.1.7
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.
4.1.1.8
RemainingCapacity( ): 0x10/0x11
This read-only command pair returns the remaining battery capacity which is compensated for the present
conditions of load, temperature and battery age. RemainingCapacity( ) is typically lower than the
uncompensated NominalAvailableCapacity( ). Units are mAh.
4.1.1.9
FullChargeCapacity( ): 0x12/13
This read-only command pair returns the capacity of the battery when fully charged with compensation for
the present conditions of temperature and battery age. FullChargeCapacity( ) is updated at regular
intervals, as specified by the IT algorithm typically lower than the uncompensated
FullAvailableCapacity( )and . Units are mAh.
14
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4.1.1.10
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EffectiveCurrent( ): 0x14/0x15
This read-only command pair returns a signed integer value that is taken from the Effective current
Calculation being used by DVC algorithm. Units are mA.
4.1.1.11
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.
4.1.1.12
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 EffectiveCurrent( ). The computation accounts for the taper
current time extension from the linear TTF computation based on a fixed EffectiveCurrent( ) rate of charge
accumulation. A value of 65,535 indicates the battery is not being charged.
4.1.1.13
StandbyCurrent( ): 0x1a/0x1b
This read-only function returns a signed integer value of the measured standby current from the Effective
Current Calculation. The StandbyCurrent( ) is an adaptive measurement. Initially it reports the standby
current programmed in Initial Standby, and after spending several seconds in standby, reports the
measured standby current.
The register value is updated every 1 second when the effective current is above the Deadband and is
less than or equal to 2 × Initial Standby. The first and last values that meet this criteria are not averaged
in, since they may not be stable values. To approximate a 1 minute time constant, each new
StandbyCurrent( ) value is computed by taking approximate 93% weight of the last standby current and
approximate 7% of the effective current calculation.
4.1.1.14
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.
4.1.1.15
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 effective current calculation is ever greater than
Initial Max Load Current, then MaxLoadCurrent( ) updates to the new current calculation.
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.
4.1.1.16
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.
4.1.1.17
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.
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AveragePower( ): 0x24/0x25
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.
4.1.1.19
TimeToEmptyAtConstantPower( ): 0x26/0x27
This read-only function returns an unsigned integer value of the predicted remaining operating time if the
battery is discharged at the AveragePower( ) value in minutes. A value of 65,535 indicates
AveragePower( ) = 0. The fuel gauge automatically updates TimeToEmptyatContantPower( ) based on the
AveragePower( ) value every 1 s.
4.1.1.20 StateofHealth( ): 0x28/0x29
0x28 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 specified in the
data flash. The range of the returned SOH percentage is 0x00 to 0x64, indicating 0 to 100%
correspondingly.
0x29 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: SOH initial value for unidentified pack
• 0x02: SOH final value, pack identified
4.1.1.21
CycleCount( ): 0x2a/0x2b
This read-only function returns an unsigned integer value of the number of cycles that the active cell has
experienced with a range of 0 to 65535. One cycle occurs when accumulated discharge ≥ CC Threshold.
The gauge maintains a separate cycle counter for both cell profiles and will reset to zero if the insertion of
a new pack has been detected.
4.1.1.22
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%.
4.1.1.23 InternalTemperature( ): 0x36/0x37
This read-only function returns an unsigned integer value of the internal temperature sensor in units of 0.1
K measured by the fuel gauge. This function can be useful as an additional system-level temperature
monitor if the main Temperature( ) function is configured for external or host reported temperature.
4.1.1.24 OperationConfiguration( ): 0x3a/0x3b
This read-only function returns the contents of the data flash Operation Configuration register and is
most useful for system level debug to quickly determine device configuration.
4.1.1.25 ApplicationStatus(): 0x6a/0x6b
This read-only function returns the contents of the data flash Host Cfg register.
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4.1.2
SLUSAE3 – OCTOBER 2012
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 4-5.
Table 4-5. Extended Data Commands
COMMAND
CODE
UNITS
SEALED
ACCESS (1) (2)
UNSEALED
ACCESS (1) (2)
Reserved
0x34...0x3b
N/A
R
R
DesignCapacity( )
NAME
0x3c / 0x3d
mAh
R
R
DataFlashClass( ) (2)
0x3e
N/A
N/A
R/W
DataFlashBlock( ) (2)
0x3f
N/A
R/W
R/W
BlockData( )
0x40…0x5f
N/A
R
R/W
BlockDataCheckSum( )
0x60
N/A
R/W
R/W
BlockDataControl( )
0x61
N/A
N/A
R/W
ApplicationStatus( )
0x6a
N/A
R
R
0x6b...0x7f
N/A
R
R
Reserved
(1)
(2)
SEALED and UNSEALED states are entered via commands to Control() 0x00/0x01.
In sealed mode, data flash CANNOT be accessed through commands 0x3e and 0x3f.
4.1.2.1
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.
4.1.2.2
DataFlashClass( ): 0x3e
UNSEALED Access: This command sets the data flash class to be accessed. The class to be accessed
must be entered in hexadecimal.
SEALED Access: This command is not available in SEALED mode.
4.1.2.3
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, a 0x01 specifies
access to the second 32-byte block, and so on.
SEALED Access: This command directs which data flash block is accessed by the BlockData( )
command. Writing a 0x01 or 0x02 instructs the BlockData( ) command to transfer the Manufacturer Info
Block. All other DataFlashBlock( ) values are reserved.
4.1.2.4
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.
4.1.2.5
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.
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SEALED Access: This byte contains the checksum for the 32 bytes of block data written to the
Manufacturer Info Block. 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.
4.1.2.6
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.
4.1.2.7
ApplicationStatus( ): 0x6a
This byte function allows the system to read the bq27620-G1 Host Cfg data flash location. See Table 6-1
for specific bit definitions.
4.1.2.8
18
Reserved — 0x6b–0x7f
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4.2
4.2.1
SLUSAE3 – OCTOBER 2012
DATA FLASH INTERFACE
ACCESSING THE DATA FLASH
The bq27620-G1 data flash is a non-volatile memory that contains bq27620-G1 initialization, default, cell
status, calibration, configuration, and user information. The data flash can be accessed in several different
ways, depending on what mode the bq27620-G1 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 4.1, DATA COMMANDS . These
commands are available when the bq27620-G1 is either in UNSEALED or SEALED modes.
Most data flash locations, however, are only accessible in UNSEALED mode by use of the bq27620-G1
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 44, 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 + 44 modulo 32 =
0x40 + 12 = 0x40 + 0x0C = 0x4C.
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 bq27620-G1 – 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.
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4.3
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MANUFACTURER INFORMATION BLOCK
The bq27620-G1 contains 32 bytes of user programmable data flash storage called the Manufacturer
Info Block. 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 information 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.
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 or 0x02 with this command causes the corresponding information blockto 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: The
Manufacturer Info Block is read-only when in SEALED mode.
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4.4
SLUSAE3 – OCTOBER 2012
ACCESS MODES
The bq27620-G1 provides three security modes (FULL ACCESS, UNSEALED, and SEALED) that control
data flash access permissions, according to Table 4-6. Data Flash refers to those data flash locations,
specified in Section 4.6, that are accessible to the user.
Table 4-6. Data Flash Access
Security Mode
Data Flash
Manufacture Info Block
FULL ACCESS
R/W
R/W
UNSEALED
R/W
R/W
SEALED
None
R
Although FULL ACCESS and UNSEALED modes appear identical, only FULL ACCESS allows the
bq27620-G1 to write access-mode transition keys.
4.5
SEALING/UNSEALING DATA FLASH
The bq27620-G1 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 bq27620-G1
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 4-2 subcommands.
When in SEALED mode, the CONTROL_STATUS [SS] bit is set, but when the UNSEAL keys are
correctly received by the bq27620-G1, 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 keys is
Key 1 followed by Key 0. The order of the bytes entered through the Control( ) command is the reverse of
what is read from the part. For example, if the Key 1 and Key 0 of the Unseal Keys returns 0x1234 and
0x5678, then the Control( ) should supply 0x3412 and 0x7856 to unseal the part.
GENERAL DESCRIPTION
Copyright © 2012, Texas Instruments Incorporated
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Product Folder Links: bq27620-G1
21
bq27620-G1
SLUSAE3 – OCTOBER 2012
4.6
www.ti.com
DATA FLASH SUMMARY
The following table summarizes the data flash locations available to the user, including their default,
minimum, and maximum values.
Table 4-7. Data Flash Summary
Subclass
ID
Subclass
Class
Offset
Name
Data
Type
Min Value
Max Value
Default Value
Units (EVSW
Units)*
0.1°C
Configuration
2
Safety
0
OT Chg
I2
0
1200
550
Configuration
2
Safety
2
OT Chg Time
U1
0
60
2
s
Configuration
2
Safety
3
OT Chg Recovery
I2
0
1200
500
0.1°C
Configuration
2
Safety
5
OT Dsg
I2
0
1200
600
0.1°C
Configuration
2
Safety
7
OT Dsg Time
U1
0
60
2
s
Configuration
2
Safety
8
OT Dsg Recovery
I2
0
1200
550
0.1°C
Configuration
32
Charge Inhibit Cfg
0
Chg Inhibit Temp Low
I2
-400
1200
0
0.1°C
Configuration
32
Charge Inhibit Cfg
2
Chg Inhibit Temp High
I2
-400
1200
450
0.1°C
Configuration
32
Charge Inhibit Cfg
4
Temp Hys
I2
0
100
50
0.1°C
Configuration
34
Charge
0
Charging Voltage
I2
0
4600
4200
mV
Configuration
34
Charge
2
Delta Temp
I2
0
500
50
0.1°C
Configuration
34
Charge
4
Suspend Low Temp
I2
-400
1200
-50
0.1°C
Configuration
34
Charge
6
Suspend High Temp
I2
-400
1200
550
0.1°C
Configuration
36
Charge Termination
0
Taper Current
I2
0
1000
100
mA
Configuration
36
Charge Termination
2
Min Taper Capacity
I2
0
1000
25
mAh
Configuration
36
Charge Termination
4
Taper Voltage
I2
0
1000
100
mV
Configuration
36
Charge Termination
6
Current Taper Window
U1
0
60
40
s
Configuration
36
Charge Termination
9
FC Set %
I1
-1
100
-1
%
Configuration
36
Charge Termination
10
FC Clear %
I1
-1
100
98
%
Configuration
36
Charge Termination
11
DODatEOC Delta T
I2
0
1000
50
0.1°C
Configuration
48
Data
0
Initial Standby
I1
-256
0
-10
mA
Configuration
48
Data
1
Initial MaxLoad
I2
-32767
0
-750
mA
Configuration
48
Data
3
CC Threshold
I2
100
32767
1050
mAh
Configuration
48
Data
6
Design Capacity
I2
0
32767
1140
mA
Configuration
48
Data
10
Design Voltage
I2
0
32767
3600
MilliVolt
Configuration
48
Data
12
SOH LoadI
I2
-32767
0
-400
mA
Configuration
48
Data
14
Default Temp
I2
0
3050
2982
°K
Configuration
48
Data
16
Data Flash Version
H2
0x0000
0xffff
0x0000
Configuration
48
Data
18
Device Name
S8
x
x
bq27620
-
Configuration
49
Discharge
0
SOC1 Set Threshold
U1
0
255
150
mA
Configuration
49
Discharge
1
SOC1 Clear Threshold
U1
0
255
175
mA
Configuration
49
Discharge
5
SysDown Set Volt Threshold
I2
0
4200
3150
mV
Configuration
49
Discharge
7
SysDown Set Volt Time
U1
0
60
2
s
Configuration
49
Discharge
8
SysDown Clear Volt
I2
0000
4200
3400
mV
Configuration
49
Discharge
15
Def Cell 0 DOD at EOC
I2
0
16384
0
Configuration
49
Discharge
17
Def Avg I Last Run
I2
-32768
32767
-50
mA
Configuration
49
Discharge
19
Def Avg P Last Run
I2
-32768
32767
-50
mWatt
Configuration
64
Registers
0
Op Config
H2
0x0000
0xffff
0x0853
Configuration
64
Registers
2
SOC Delta
U1
0
25
1
%
Configuration
64
Registers
3
i2c Timeout
U1
0
7
4
%
Configuration
64
Registers
4
DF Wr Ind Wait
U2
0
65535
0
%
Configuration
64
Registers
6
OpConfig B
H1
0x00
0xff
0x4b
Configuration
64
Registers
7
OpConfig C
H1
0x00
0xff
0x28
Configuration
64
Registers
8
Clk Ctl Reg
H1
0x00
0x0f
0x09
Hex
Configuration
68
Power
0
Flash Update OK Voltage
I2
0
4200
2800
mV
Configuration
68
Power
4
Sleep Current
I2
0
100
10
mA
Configuration
68
Power
6
Sleep Time
U1
0
100
20
s
22
GENERAL DESCRIPTION
Copyright © 2012, Texas Instruments Incorporated
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Product Folder Links: bq27620-G1
bq27620-G1
www.ti.com
SLUSAE3 – OCTOBER 2012
Table 4-7. Data Flash Summary (continued)
Class
Subclass
ID
Subclass
Offset
Name
Data
Type
Min Value
Max Value
Default Value
Units (EVSW
Units)*
Configuration
68
Power
7
Hibernate I
U2
0
700
8
mA
Configuration
68
Power
9
Hibernate V
U2
2400
3000
2550
mV
System Data
57
Manufacturer Info
0-31
Block [0-31]
H1
0x00
0xff
[Table]
-
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
21
Max Res Factor
U1
0
255
15
Gas Gauging
80
IT Cfg
22
Min Res Factor
U1
0
255
5
Gas Gauging
80
IT Cfg
24
Ra Filter
U2
0
1000
800
Gas Gauging
80
IT Cfg
44
Terminate Voltage
I2
-32768
32767
3200
mV
Gas Gauging
80
IT Cfg
46
Term V Delta
I2
0
4200
200
mV
Gas Gauging
80
IT Cfg
49
ResRelax Time
U2
0
65534
500
s
Gas Gauging
80
IT Cfg
53
User Rate-mA
I2
-2000
-100
0
mA
Gas Gauging
80
IT Cfg
55
User Rate-mW
I2
-7200
-350
0
cW
Gas Gauging
80
IT Cfg
57
Reserve Cap-mAh
I2
0
9000
0
mA
Gas Gauging
80
IT Cfg
59
Reserve Cap-mWh
I2
0
14000
0
10mW
Gas Gauging
80
IT Cfg
64
Min Delta Voltage
I2
-32000
32000
0
Gas Gauging
80
IT Cfg
68
Ra Max Delta
U2
0
65535
44
Gas Gauging
80
IT Cfg
70
DeltaV Max dV
U2
0
65535
10
mV
Gas Gauging
80
IT Cfg
72
Max Res Scale
U2
0
32767
5000
Num
Gas Gauging
80
IT Cfg
74
Min Res Scale
U2
0
32767
200
Num
Gas Gauging
80
IT Cfg
76
Fast Scale Start SOC
U1
0
100
10
%
Gas Gauging
80
IT Cfg
83
LC Dection Sensitivity
U1
0
100
80
%
Gas Gauging
81
Current Thresholds
6
Dsg Relax Time
U2
0
8191
60
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
81
Current Thresholds
10
Transient Factor Charge
U1
0
255
128
Gas Gauging
81
Current Thresholds
11
Transient Factor Discharge
U1
0
255
128
Gas Gauging
81
Current Thresholds
12
Max IR Correct
U2
0
1000
400
Gas Gauging
82
State
0
Host Cfg
H1
0x01
0xff
0x00
Gas Gauging
82
State
1
Qmax Cell 0
I2
0
32767
16384
Gas Gauging
82
State
3
Cycle Count0
U2
0
65535
0
Gas Gauging
82
State
5
Qmax Cell 1
I2
0
32767
16384
Gas Gauging
82
State
7
Cycle Count 1
U2
0
65535
0
Gas Gauging
82
State
9
Chg DoD0 C 0
U2
0
65535
0
Gas Gauging
82
State
11
Chg DoD0 C 1
U2
0
65535
0
Gas Gauging
82
State
15
DoDatEOC
U2
0
65535
0
Gas Gauging
82
State
25
T Rise
U2
0
65535
20
Num
Gas Gauging
82
State
27
T Time Constant
U2
0
65535
1000
Num
OCV Table
83
OCVa Table
0
Chem ID
H2
0x0000
0xffff
0x1124
hex
Default Ra
Tables
85
Def Ra
0
Cell0 R_a flag
H1
0x00
0x00
0x55
-
Default Ra
Tables
85
Def Ra
1
Cell0 R_a 0
I2
1
32767
424
2-10Ω
Default Ra
Tables
85
Def Ra
3
Cell0 R_a 1
I2
1
32767
509
2-10Ω
Default Ra
Tables
85
Def Ra
5
Cell0 R_a 2
I2
1
32767
538
2-10Ω
Default Ra
Tables
85
Def Ra
7
Cell0 R_a 3
I2
1
32767
535
2-10Ω
Default Ra
Tables
85
Def Ra
9
Cell0 R_a 4
I2
1
32767
461
2-10Ω
Default Ra
Tables
85
Def Ra
11
Cell0 R_a 5
I2
1
32767
460
2-10Ω
Default Ra
Tables
85
Def Ra
13
Cell0 R_a 6
I2
1
32767
509
2-10Ω
GENERAL DESCRIPTION
Copyright © 2012, Texas Instruments Incorporated
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Product Folder Links: bq27620-G1
mΩ
mV
rate
rate
23
bq27620-G1
SLUSAE3 – OCTOBER 2012
www.ti.com
Table 4-7. Data Flash Summary (continued)
Class
Subclass
ID
Subclass
Offset
Name
Data
Type
Min Value
Max Value
Default Value
Units (EVSW
Units)*
Default Ra
Tables
85
Def Ra
15
Cell0 R_a 7
I2
1
32767
578
2-10Ω
Default Ra
Tables
85
Def Ra
17
Cell0 R_a 8
I2
1
32767
563
2-10Ω
Default Ra
Tables
85
Def Ra
19
Cell0 R_a 9
I2
1
32767
544
2-10Ω
Default Ra
Tables
85
Def Ra
21
Cell0 R_a 10
I2
1
32767
574
2-10Ω
Default Ra
Tables
85
Def Ra
23
Cell0 R_a 11
I2
1
32767
726
2-10Ω
Default Ra
Tables
85
Def Ra
25
Cell0 R_a 12
I2
1
32767
956
2-10Ω
Default Ra
Tables
85
Def Ra
27
Cell0 R_a 13
I2
1
32767
1222
2-10Ω
Default Ra
Tables
85
Def Ra
29
Cell0 R_a 14
I2
1
32767
8099
2-10Ω
Ra Table
88
R_a0
0
Cell0 R_a flag
H1
0x00
0x255
0x55
-
Ra Table
88
R_a0
1
Cell0 R_a 0
I2
1
32767
424
2-10Ω
Ra Table
88
R_a0
3
Cell0 R_a 1
I2
1
32767
509
2-10Ω
Ra Table
88
R_a0
5
Cell0 R_a 2
I2
1
32767
538
2-10Ω
Ra Table
88
R_a0
7
Cell0 R_a 3
I2
1
32767
535
2-10Ω
Ra Table
88
R_a0
9
Cell0 R_a 4
I2
1
32767
461
2-10Ω
Ra Table
88
R_a0
11
Cell0 R_a 5
I2
1
32767
460
2-10Ω
Ra Table
88
R_a0
13
Cell0 R_a 6
I2
1
32767
509
2-10Ω
Ra Table
88
R_a0
15
Cell0 R_a 7
I2
1
32767
578
2-10Ω
Ra Table
88
R_a0
17
Cell0 R_a 8
I2
1
32767
563
2-10Ω
Ra Table
88
R_a0
19
Cell0 R_a 9
I2
1
32767
544
2-10Ω
Ra Table
88
R_a0
21
Cell0 R_a 10
I2
1
32767
574
2-10Ω
Ra Table
88
R_a0
23
Cell0 R_a 11
I2
1
32767
726
2-10Ω
Ra Table
88
R_a0
25
Cell0 R_a 12
I2
1
32767
956
2-10Ω
Ra Table
88
R_a0
27
Cell0 R_a 13
I2
1
32767
1222
2-10Ω
Ra Table
88
R_a0
29
Cell0 R_a 14
I2
1
32767
8099
2-10Ω
Ra Table
89
R_a1
0
Cell1 R_a flag
H1
0x00
0x255
0x55
-
Ra Table
89
R_a1
1
Cell1 R_a 0
I2
1
32767
424
2-10Ω
Ra Table
89
R_a1
3
Cell1 R_a 1
I2
1
32767
509
2-10Ω
Ra Table
89
R_a1
5
Cell1 R_a 2
I2
1
32767
538
2-10Ω
Ra Table
89
R_a1
7
Cell1 R_a 3
I2
1
32767
535
2-10Ω
Ra Table
89
R_a1
9
Cell1 R_a 4
I2
1
32767
461
2-10Ω
Ra Table
89
R_a1
11
Cell1 R_a 5
I2
1
32767
460
2-10Ω
Ra Table
89
R_a1
13
Cell1 R_a 6
I2
1
32767
509
2-10Ω
Ra Table
89
R_a1
15
Cell1 R_a 7
I2
1
32767
578
2-10Ω
Ra Table
89
R_a1
17
Cell1 R_a 8
I2
1
32767
563
2-10Ω
Ra Table
89
R_a1
19
Cell1 R_a 9
I2
1
32767
544
2-10Ω
Ra Table
89
R_a1
21
Cell1 R_a 10
I2
1
32767
574
2-10Ω
Ra Table
89
R_a1
23
Cell1 R_a 11
I2
1
32767
726
2-10Ω
Ra Table
89
R_a1
25
Cell1 R_a 12
I2
1
32767
956
2-10Ω
Ra Table
89
R_a1
27
Cell1 R_a 13
I2
1
32767
1222
2-10Ω
Ra Table
89
R_a1
29
Cell1 R_a 14
I2
1
32767
8099
2-10Ω
Ra Table
90
R_a0x
0
xCell0 R_a flag
H1
0x00
0x255
0x55
-
Ra Table
90
R_a0x
1
xCell0 R_a 0
I2
1
32767
424
-10
2 Ω
Ra Table
90
R_a0x
3
xCell0 R_a 1
I2
1
32767
509
2-10Ω
24
GENERAL DESCRIPTION
Copyright © 2012, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Links: bq27620-G1
bq27620-G1
www.ti.com
SLUSAE3 – OCTOBER 2012
Table 4-7. Data Flash Summary (continued)
Class
Subclass
ID
Subclass
Offset
Name
Data
Type
Min Value
Max Value
Default Value
Units (EVSW
Units)*
Ra Table
90
R_a0x
5
xCell0 R_a 2
I2
1
32767
538
2-10Ω
Ra Table
90
R_a0x
7
xCell0 R_a 3
I2
1
32767
535
2-10Ω
Ra Table
90
R_a0x
9
xCell0 R_a 4
I2
1
32767
461
2-10Ω
Ra Table
90
R_a0x
11
xCell0 R_a 5
I2
1
32767
460
2-10Ω
Ra Table
90
R_a0x
13
xCell0 R_a 6
I2
1
32767
509
2-10Ω
Ra Table
90
R_a0x
15
xCell0 R_a 7
I2
1
32767
578
2-10Ω
Ra Table
90
R_a0x
17
xCell0 R_a 8
I2
1
32767
563
2-10Ω
Ra Table
90
R_a0x
19
xCell0 R_a 9
I2
1
32767
544
2-10Ω
Ra Table
90
R_a0x
21
xCell0 R_a 10
I2
1
32767
574
2-10Ω
Ra Table
90
R_a0x
23
xCell0 R_a 11
I2
1
32767
726
2-10Ω
Ra Table
90
R_a0x
25
xCell0 R_a 12
I2
1
32767
956
2-10Ω
Ra Table
90
R_a0x
27
xCell0 R_a 13
I2
1
32767
1222
2-10Ω
Ra Table
90
R_a0x
29
xCell0 R_a 14
I2
1
32767
8099
2-10Ω
Ra Table
91
R_a1x
0
xCell1 R_a flag
H1
0x00
0x255
0x55
-
Ra Table
91
R_a1x
1
xCell1 R_a 0
I2
1
32767
424
2-10Ω
Ra Table
91
R_a1x
3
xCell1 R_a 1
I2
1
32767
509
2-10Ω
Ra Table
91
R_a1x
5
xCell1 R_a 2
I2
1
32767
538
2-10Ω
Ra Table
91
R_a1x
7
xCell1 R_a 3
I2
1
32767
535
2-10Ω
Ra Table
91
R_a1x
9
xCell1 R_a 4
I2
1
32767
461
2-10Ω
Ra Table
91
R_a1x
11
xCell1 R_a 5
I2
1
32767
460
2-10Ω
Ra Table
91
R_a1x
13
xCell1 R_a 6
I2
1
32767
509
2-10Ω
Ra Table
91
R_a1x
15
xCell1 R_a 7
I2
1
32767
578
2-10Ω
Ra Table
91
R_a1x
17
xCell1 R_a 8
I2
1
32767
563
2-10Ω
Ra Table
91
R_a1x
19
xCell1 R_a 9
I2
1
32767
544
2-10Ω
Ra Table
91
R_a1x
21
xCell1 R_a 10
I2
1
32767
574
2-10Ω
Ra Table
91
R_a1x
23
xCell1 R_a 11
I2
1
32767
726
2-10Ω
Ra Table
91
R_a1x
25
xCell1 R_a 12
I2
1
32767
956
2-10Ω
Ra Table
91
R_a1x
27
xCell1 R_a 13
I2
1
32767
1222
2-10Ω
Ra Table
91
R_a1x
29
xCell1 R_a 14
I2
1
32767
8099
2-10Ω
Calibration
104
Data
2
Int Temp Offset
I1
-128
127
0
Calibration
104
Data
3
Ext Temp Offset
I1
-128
127
0
Calibration
104
Data
4
Pack V Offset
I1
-128
127
0
Security
112
Codes
0
Sealed to Unsealed
H4
0x0000000
0
0xffffffff
0x00000000
-
Security
112
Codes
4
Unsealed to Full
H4
0x0000000
0
0xffffffff
0x00000000
-
Security
112
Codes
8
FactRestore Key
H4
0x0000000
0
0xffffffff
0x00000000
-
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5 FUNCTIONAL DESCRIPTION
5.1
FUEL GAUGING
The bq27620-G1 measures cell voltage and temperature to determine battery SOC. Current is not directly
measured but is estimated by the Impedance Track™ with Dynamic Voltage Correlation (DVC) algorithm.
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 battery impedance determine chemical state of charge. The bq27620-G1
acquires and updates the battery-impedance profile during normal battery usage 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 bq27620-G1 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 Voltage( ) falls below the system shut down threshold voltage, SysDown Set Volt Threshold, the
[SYSDOWN] flag is set, serving as a final warning to shut down the system. The SOC_INT also signals.
When Voltage( ) rises above SysDown Clear Voltage and the [SYSDOWM] flag has already been set,
the [SYSDOWN] flag is cleared. The SOC_INT also signals such change. All units are in mV.
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5.2
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IMPEDANCE TRACK™ VARIABLES
The bq27620-G1 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.
5.2.1
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.
5.2.2
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 5-1 are available.
Table 5-1. Constant-Current Model Used When Load Mode = 0
LoadSelect Value
0
1(default)
Current Model Used
Average discharge current from previous cycle: There is an internal register that records the average discharge
current through each entire discharge cycle. The previous average is stored in this register.
Present average discharge current: This is the average discharge current from the beginning of this discharge cycle
until present time.
2
Average current: based on EffectiveCurrent( )
3
Current: based off of a low-pass-filtered version of EffectiveCurrent( ) (τ =14 s)
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-mA. This mode provides a completely user-configurable method.
If Load Mode = 1 (Constant Power) then the following options shown in Table 5-2 are available
Table 5-2. Constant-Power Model Used When Load Mode = 1
LoadSelect Value
Power Model Used
0
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(default)
5.2.3
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 EffectiveCurrent( ) and Voltage( ).
3
Current × voltage: based off of a low-pass-filtered version of EffectiveCurrent( ) (τ=14 s) 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-10mW. This mode provides 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.
5.2.4
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.
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5.2.5
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Dsg Current Threshold Rate
This register is used as a threshold by many functions in the bq27620-G1 to determine if actual discharge
current is flowing into or out of the cell. The default for this register is in Section 4.6, which should be
sufficient for most applications. This threshold should be set low enough to be below any normal
application load current but high enough to prevent noise or drift from affecting the measurement.
5.2.6
Chg Current Threshold Rate
This register is used as a threshold by many functions in the bq27620-G1 to determine if actual charge
current is flowing into or out of the cell. The default for this register is in Section 4.6, which should be
sufficient for most applications. This threshold should be set low enough to be below any normal charge
current but high enough to prevent noise or drift from affecting the measurement.
5.2.7
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 bq27620-G1
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 in Section 4.6 and should be above the
standby current of the system.
Either of the following criteria must be met to enter relaxation mode:
• | EffectiveCurrent( ) | < | Quit Current | for Dsg Relax Time
• | EffectiveCurrent( ) | < | Quit Current | for Chg Relax Time
After about 5 minutes in relaxation mode, the bq27620-G1 attempts to take accurate OCV readings. An
additional requirement of dV/dt < 1 μV/s is required for the bq27620-G1 to perform optimization cycle.
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 EffectiveCurrent( ) to remain above the
QuitCurrent threshold before exiting relaxation mode.
5.2.8
Delta Voltage
The bq27620-G1 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.
5.2.9
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. Arbitrations happen on pack insert and based on a Ra measurement. No
user changes should be made except for reading/writing the values from a pre-learned pack (part of the
process for creating golden image files).
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5.3
5.3.1
SLUSAE3 – OCTOBER 2012
DETAILED PIN DESCRIPTION
The Operation Configuration Register
Some bq27620-G1 pins are configured via the Operation Configuration data flash register, as indicated
in Table 5-3. This register is programmed/read via the methods described in Section 4.2.1, Accessing the
Data Flash. The register is located at subclass = 64, offset = 0.
Table 5-3. Operation Configuration Bit Definition
High Byte
Default =
bit7
RESCAP
0
bit6
BATG_OVR
0
bit5
INT_BREM
0
bit4
PFC1
0
Low Byte
Default =
INT_FOCV
0
IDSELEN
1
LDODEOC
1
RMFCC
1
bit3
PFC2
1
0x08
SOCPOL
0
0x73
bit2
–
0
bit1
–
0
bit0
0
BATGPOL
0
BATLPOL
1
TEMPS
1
RESCAP = No-load rate of compensation is applied to the reserve capacity calculation. True when set.
BATG_OVR = BAT_GD override bit. If the gauge enters Hibernate only due to the cell voltage, the BAT_GD pin will not negate. True when
set.
INT_BERM = Battery removal interrupt bit. The SOC_INT pulses 1ms when the battery removal interrupt is enabled. True when set.
PFC1/PFC2 = Pin function code (PFC) mode selection: PFC 0, 1, or 2 selected by 0/0, 0/1, or 1/0, respectively.
INT_FOCV = Indication of the measurement of the OCV during the initialization. The SOC_INT will pulse during the first measurement if this
bit is set. True when set.
IDSELEN = Enables cell profile selection feature. True when set.
LDODEOC = Learned Dod at EOC is the recording of DoD at EOC when set. If cleared the bq27620 records the the V_charger voltage and
uses it to dynamically compute DoD at EOC based on the current temperature. True when set.
RMFCC = RM is updated with the value from FCC, on valid charge termination. True when set.
SOCPOL = SOC interrupt polarity is active-low. True when cleared.
BATGPOL = BAT_GD pin is active-low. True when cleared.
BATLPOL = BAT_LOW pin is active-high. True when set.
TEMPS = Selects external thermistor for Temperature( ) measurements. True when set.
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Some bq27620-G1 pins are configured via the Operation Configuration B data flash register, as
indicated in Table 5-4. This register is programmed/read via the methods described in Section 4.2.1:
Accessing the Data Flash. The register is located at subclass = 64, offset = 9.
Table 5-4. Operation Configuration B Bit Definition
Byte
bit7
WRTEMP
bit6
BIE
bit5
BL_INT
bit4
GNDSEL
bit3
FCE
bit2
DFWrIndBL
Default=
0
1
0
0
1
0
bit1
RFACTSTE
P
1
bit0
INDFACRE
S
1
0x4B
WRTEMP = Enables the temperature write. The temperature could be written by the host. True when set.
BIE = Battery insertion detection enable. When the battery insertion detection is disabled, the gauge relies on the host command to set the
BAT_DET bit. True when set.
BL_INT = Battery low interrupt enable. True when set.
GNDSEL = The ADC ground select control. The Vss (Pin D1) is selected as ground reference when the bit is clear. Pin A1 is selected when
the bit is set.
FCE = The Fast Convergence Enabled.
DFWrIndBL = DataFlash Write Indication. SOC_INT is used for indication if the bit is clear. BAT_LOW is used for indication if the bit is set.
RFACTSTEP = Enables Ra Step up/down to Min/Max Res Factor before disabling Ra updates.
INDFACRES = Although the default is '1', the function associated with this bit has been removed from firmware.
Table 5-5. Operation Configuration C Bit Definition
Byte
Default =
bit7
BATGSPUE
N
0
bit6
BATGWPU
EN
0
bit5
bit4
bit3
BATLSPUE BATLWPUE
VCCE
N
N
1
0
1
0x28
bit2
–
bit1
DeltaVOpt1
bit0
DeltaVOpt0
0
0
0
BATGSPUEN = BAT_GD pin strong pull-up enable.
BATGWPUEN = BAT_GD pin weak pull-up enable.
BATLSPUEN = BAT_LOW pin strong pull-up enable.
BATLWPUEN = BAT_LOW pin weak pull-up enable.
VCCE = Voltage Consistency Check Enable.
DeltaVOpt[1:0] = Configures options for determination of Delta Voltage which is defined as the maximum difference in Voltage( ) during
normal load and short load spikes. Delta Voltage is a used as a compensation factor for calculating for RemainingCapacity( ) under pulsed
loads.
0/0 = Standard DeltaV. Average variance from steady state voltage used to determine end of discharge voltage. (Default)
0/1 = No Averaging. The last instantaneous change in Voltage( ) from steady state is used to determine the end of discharge voltage.
1/0 = Use the value in Min Delta Voltage.
1/1 = Not used.
5.3.2
Pin Function Code Descriptions
This fuel gauge has several pin-function configurations available for the end application. Each
configuration is assigned a pin function code, or PFC, specified by Op Config [PFC_CFG1, PFC_CFG0].
(see Table 5-6 below.) If the fuel gauge is configured to measure external temperature via Op Config
[TEMPS], a voltage bias of approximately 125 mSec will be applied periodically to the external thermistor
network in order to make a temperature measurement.
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Table 5-6. Pin Function Code Summary
External Thermistor Bias Rate
([TEMPS]=1 only)
PFC
PFC_CFG
[1:0]
Discharge
Charge
Sleep
0
0/0
1 / sec
1 / sec
1 / 20
sec
1
0/1
2
1/0
None
N/A
A shared external thermistor is supported between the fuel gauge and a charger IC;
however, the BAT_GD pin is not used to interface with the charger IC. The fuel gauge
will bias the thermistor for battery temperature measurement and BAT INSERT
CHECK mode (If OpConfig B [BIE] = 1) under discharge and relaxation conditions
only so the charger IC can separately bias the thermistor during charge mode.
3
1/1
1 / sec
Follows Flags( )
[FC] flags bit.
Used to disable a battery charger IC when fuel gauge has determined the battery is
fully charged. The BAT_GD pin reflects the logical status of the Flags( ) [FC] bit and
is typically connected directly to the charger's Charge Enable/Disable (CE/CD) pin or
via a network to drive the charger's Temperature Sense (TS) pin.
5.3.3
BAT_GD pin
Usage for PFC
N/A
Temperaturebased Charge
Inhibit.
Pin Function Description
A dedicated external thermistor is used for the fuel gauge to monitor battery
temperature in all conditions. The BAT_GD pin is not used to interface with a charger
IC.
A dedicated external thermistor is used for the fuel gauge to monitor battery
temperature in all conditions. If battery charging temperature falls outside of the
preset range defined in data flash, a charger can be disabled via the BAT_GD pin
until cell temperature recovers. See Charge Inhibit and Suspend, for additional
details.
BAT_LOW Pin
The BAT_LOW pin provides a system processor with an electrical indicator of battery status. The signaling
on the BAT_LOW pin follows the status of the [SOC1] bit in the Flags( ) register. Note that the polarity of
the BAT_LOW pin can be inverted via the [BATL_POL] bit of Operation Configuration.
5.3.4
Power Path Control With the BAT_GD Pin
The bq27620-G1 must operate in conjunction with other electronics in a system appliance, such as
chargers or other ICs and application circuits that draw appreciable power. After a battery is inserted into
the system, there should be no charging current or a discharging current higher than C/20, so that an
accurate OCV can be read. The OCV is used for helping determine which battery profile to use, as it
constitutes part of the battery impedance measurement
When a battery is inserted into a system, the Impedance Track™ algorithm requires that no charging of
the battery takes place and that any discharge is limited to less than C/20—these conditions are sufficient
for the fuel gauge to take an accurate OCV reading. To disable these functions, the BAT_GD pin is merely
negated from the default setting. Once an OCV reading has be made, the BAT_GD pin is asserted,
thereby enabling battery charging and regular discharge of the battery. The Operation Configuration
[BATG_POL] bit can be used to set the polarity of the battery good signal, should the default configuration
need to be changed.
Figure 5-1 details how the BAT_GD pin functions in the context of battery insertion and removal, as
well as NORMAL vs. SLEEP modes.
In PFC 1, the BAT_GD pin is also used to disable battery charging when the bq27620-G1 reads
battery temperatures outside the range defined by [Charge Inhibit Temp Low, Charge Inhibit Temp
High]. The BAT_GD line is asserted once temperature falls within the range [Charge Inhibit Temp
Low + Temp Hys, Charge Inhibit Temp High – Temp Hys].
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POR
Exit From HIBERNATE
Battery Removed
Exit From HIBERNATE
Communication Activity
AND Comm address is for bq27520
bq27520 clears Control Status
[HIBERNATE ] = 0
Recommend Host also set Control
Status [HIBERNATE] = 0
BAT INSERT CHECK
Check for battery insertion
from HALT state.
No gauging
Flags [BAT _DET] = 0
Entry to NORMAL
Exit From NORMAL
Flags [BAT _DET] = 1
Flags [BAT _DET] = 0
Exit From SLEEP
NORMAL
Flags [BAT_DET] = 0
Fuel gauging and data
updated every 1s
HIBERNATE
Wakeup From HIBERNATE
Communication Activity
AND
Comm address is NOT for bq27620
Disable all bq27620
subcircuits except GPIO.
Negate BAT_GD
Exit From SLEEP
| EffectiveCurrent( ) | > Sleep Current
OR
Current is Detected above IWAKE
Entry to SLEEP
Operation Configuration[SLEEP] = 1
AND
| EffectiveCurrent | ≤ Sleep Current
AND
Control Status[SNOOZE] = 0
Exit From WAIT_HIBERNATE
Cell relaxed
AND
| EffectiveCurrent | < Hibernate
Current
WAIT_HIBERNATE
SLEEP
OR
V CELL
Cell relaxed
AND
< Hibernate Voltage
Fuel gauging and data
updated every 20 seconds
BAT_GD unchanged
Exit From WAIT _HIBERNATE
Host must set Control Status
[HIBERNATE ] = 0
AND
VCELL > Hibernate Voltage
System Shutdown
Fuel gauging and data
updated every 20 seconds
(LFO ON and HFO OFF)
Exit From SLEEP
(Host has set Control Status
[HIBERNATE] = 1
OR
VCELL < Hibernate Voltage
System Sleep
Figure 5-1. Power Mode Diagram
5.3.5
Battery Detection Using the BI/TOUT Pin
During power-up or hibernate activities, or any other activity where the bq27620-G1 needs to determine
whether a battery is connected or not, the fuel gauge applies a test for battery presence. First, the
BI/TOUT pin is put into high-Z status. The weak 1.8MΩ pull-up resistor will keep the pin high while no
battery is present. When a battery is inserted (or is already inserted) into the system device, the BI/TOUT
pin will be pulled low. This state is detected by the fuel gauge, which polls this pin every second when the
gauge has power. A battery-disconnected status is assumed when the bq27620-G1 reads a thermistor
voltage that is near 2.5V.
5.3.6
SOC_INT pin
The SOC_INT pin generates a pulse of different pulse widths under various conditions as indicated by the
table below. After initialization only one SOC_INT pulse will be generated within any given one second
time slot and therefore, may indicate multiple event conditions.
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Table 5-7. SOC_INT Pulse Condition and Width
Enable Condition
Pulse Width
Comment
During charge, when the SOC is greater than (>) the points, 100% - n
× SOC_Delta and 100%;
During discharge, when the SOC reaches (≤) the points 100% - n ×
SOC_Delta and 0%;
where n is an integer starting from 0 to the number generating SOC no
less than 0%
SOC_Delta
Point
SOC_Delta ≠ 0
1 ms
SOC1 Set
Always
1 ms
SOC1 Clear
Always
1 ms
SysDown Set Always
1 ms
SysDown
Clear
Always
1 ms
State
Change
SOC_Delta ≠ 0
1 ms
When there is a state change including charging, discharging and
relaxation. This function is disabled when SOC_Delta is set to 0.
INT_BREM bit is set in
OpConfig AND BIE bit is
set
1 ms
This function is disabled when BIE is cleared.
After Initialization
About 165ms. Same
as the OCV
command execution
time period
SOC_INT pulses for the OCV command after the initialization.
OCV
Command
OCV
Command
INT_FOCV bit is set in
OpConfig
About 165ms. Same
as the OCV
command execution
time period
This command is to generate the SOC_INT pulse during the
initialization.
Data Flash
Write
After Initialization AND
DFWrIndWaitTime ≠ 0
Programmmable
SOC_INT is used to indicate the data flash update. The gauge will wait
pulse width flash (see DFWrIndWaitTime times 5μs after the SOC_INT signal to start the
comment)
data flash update. This function is disabled if DFWrIndWaitTime is set
to 0.
OTC or OTD
Flags
Always
Battery
Removal
1 ms
When RSOC reached the SOC1 Set or Clear threshold set in the Data
Flash and BL_INT bit in Operation Configuration B is set.
When the Battery Voltage reached the SysDown Set or Clear threshold
set in the Data Flash
Upon first assertion of Flags[OTC] or Flags[OTD] over temperature
conditions.
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TEMPERATURE MEASUREMENT
The bq27620-G1 measures battery temperature via its TS input, in order to supply battery temperature
status information to the fuel gauging algorithm and charger-control sections of the gauge. Alternatively, it
can also measure internal temperature via its on-chip temperature sensor, but only if the [TEMPS] bit of
the Operation Configuration register is cleared. The [GNDSEL] bit of Operation Configuration B register
selects the ground reference of the ADC converter for temperature measurement.
Regardless of which sensor is used for measurement, a system processor can request the current battery
temperature by calling the Temperature( ) function (see Section 4.1.1, Standard Data Commands, for
specific information).
The thermistor circuit requires the use of an external NTC 103AT-type thermistor. Additional circuit
information for connecting this thermistor to the bq27620-G1 is shown in Section 8, Reference Schematic.
5.5
5.5.1
OVERTEMPERATURE INDICATION
Overtemperature: Charge
If during charging, Temperature( ) reaches the threshold of OT Chg for a period of OT Chg Time and
EffectiveCurrent( ) > 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, then the feature is completely disabled.
5.5.2
Overtemperature: Discharge
If during discharging, Temperature( ) reaches the threshold of OT Dsg for a period of OT Dsg Time, and
EffectiveCurrent( ) ≤ –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, then feature is completely disabled.
5.6
5.6.1
CHARGING AND CHARGE-TERMINATION INDICATION
Detecting Charge Termination
For proper bq27620-G1 operation, the cell charging voltage must be specified by the user. The default
value for this variable is Charging Voltage Section 4.6.
The bq27620-G1 detects charge termination when (1) during 2 consecutive periods of Current Taper
Window, the EffectiveCurrent( ) is < Taper Current, (2) during the same periods, the accumulated
change in capacity > Min Taper Charge /Current Taper Window, and (3) Voltage( ) > Charging
Voltage – Taper Voltage. When this occurs, the [CHG] bit of Flags( ) is cleared. Also, if the [RMFCC] bit
of Operation Configuration is set, then RemainingCapacity( ) is set equal to FullChargeCapacity( ).
5.6.2
Charge Inhibit and Suspend
The bq27620-G1 can indicate when battery temperature has fallen below or risen above predefined
thresholds Charge Inhibit Temp Low or Charge Inhibit Temp High, respectively. In this mode, the
[CHG_INT] bit is set and the BAT_GD pin is deserted to indicate this condition. The [CHG_INT] bit is
cleared and the BAT_GD pin is asserted once the battery temperature returns to the range [Charge
Inhibit Temp Low + Temp Hys, Charge Inhibit Temp High – Temp Hys].
When PFC = 1, the bq27620-G1 can indicate when battery temperature has fallen below or risen above
predefined thresholds Suspend Low Temp or Suspend High Temp, respectively. In this mode, the
[XCHG] bit is set to indicate this condition. The [XCHG] bit is cleared once the battery temperature returns
to the range [Charge Inhibit Temp Low + Temp Hys, Charge Inhibit Temp High – Temp Hys].
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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 Low Temp or
above the Suspend Low Temp. Therefore, the window [Charge Inhibit Temp Low, Charge Inhibit Temp
High] must be inside the window of [Suspend Low Temp, Suspend High Temp].
5.7
POWER MODES
The bq27620-G1 has different power modes: BAT INSERT CHECK, NORMAL and HIBERNATE. In
NORMAL mode, the bq27620-G1 is fully powered and can execute any allowable task. In HIBERNATE
mode, the fuel gauge is in a low power state, but can be woken up by communication or certain I/O
activity. Finally, the BAT INSERT CHECK mode is a powered-up, but low-power halted, state, where the
bq27620-G1 resides when no battery is inserted into the system.
The relationship between these modes is shown in Figure 5-1.
5.7.1
BAT INSERT CHECK Mode
This mode is a halted-CPU state that occurs when an adapter, or other power source, is present to power
the bq27620-G1 (and system), yet no battery has been detected. When battery insertion is detected, a
series of initialization activities begin, which include: OCV measurement, setting the BAT_GD pin, and
selecting the appropriate battery profiles.
Some commands, issued by a system processor, can be processed while the bq27620-G1 is halted in this
mode. The gauge will wake up to process the command, then return to the halted state awaiting battery
insertion.
5.7.2
NORMAL MODE
The fuel gauge is in NORMAL mode when not in any other power mode. During this mode,
EffectiveCurrent( ), 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.
5.7.3
HIBERNATE MODE
HIBERNATE mode should be used when the system equipment needs to enter a 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 or a POR occurs.
I2C Communication that is not directed to the gauge will not wake the gauge.
It is important that BAT_GD be de-asserted status (no battery charging/discharging). This prevents a
charger application from inadvertently charging the battery before an OCV reading can be taken. It is the
system’s responsibility to wake the bq27620-G1 after it has gone into HIBERNATE mode. After waking,
the gauge can proceed with the initialization of the battery information (OCV, profile selection, etc.)
FUNCTIONAL DESCRIPTION
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6 APPLICATION-SPECIFIC INFORMATION
6.1
BATTERY PROFILE STORAGE AND SELECTION
6.1.1
Common Profile Aspects
The bq27620-G1 maintains two chemistry profiles, PACK0 and PACK1. These profiles hold dynamic
battery data, and keep track of the status for up to two of the most recent batteries used. When a battery
pack is removed from host equipment, the bq27620-G1 selects the battery information when the battery is
re-inserted. This way, Impedance Track™ algorithm has a means of recovering battery-status information,
thereby maintaining good state-of-charge (SOC) estimates.
The bq27620-G1 can manage the information on two removable battery packs. In addition, the gauge has
two default battery profiles available to store battery information. The profiles are used to provide the
Impedance Track™ algorithm with the default information on two possible battery types expected to be
used with the end-equipment. If a new pack is inserted that replaces an older worn out pack, the gauge
automatically selects from one of the default profiles and writes that data into the oldest of the PACK0 or
PACK1 profile.
6.1.2
Activities Upon Pack Insertion
6.1.2.1
First OCV and Impedance Measurement
At power-up the BAT_GD pin is inactive, so that the system might not obtain power from the battery (this
depends on actual implementation). In this state, the battery should be put in a condition with load current
less than C/20. Next, the bq27620-G1 measures its first open-circuit voltage (OCV) via the BAT pin. The
[OCVCMDCOMP] bit will set once the OCV measurement is completed. Depending on the load current,
the [OCVFAIL] bit indicates whether the OCV reading is valid. From the OCV(SOC) table, the SOC of the
inserted battery is found. Then the BAT_GD pin is made active, and the impedance of the inserted battery
is calculated from the measured voltage and the load current: Z(SOC) = ( OCV(SOC) – V ) / I. This
impedance is compared with the impedance of the dynamic profiles, Packn, and the default profiles, Defn,
for the same SOC (the letter n depicts either a 0 or 1).The [INITCOMP] bit will be set afterwards and the
OCV command could be issued
6.1.3
Reading HostCfg
The HostCfg data flash location contains cell profile status information, and can be read using the
ApplicationStatus( ) extended command (0x6a). The bit configuration of this function/location is shown in
Table 6-1.
Table 6-1. HostCfg Bit Definitions.
HostCfg
Byte
bit7
—
bit6
—
bit5
—
bit4
—
bit3
OPTCMP
bit2
—
bit1
—
bit0
LU_ PROF
LU_PROF = Last profile used by fuel gauge. Cell0 last used when cleared. Cell1 last used when set. Default is 0.
OPTCMP = OPTMIZ bit is set. Default is 0.
36
APPLICATION-SPECIFIC INFORMATION
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7 COMMUNICATIONS
I2C INTERFACE
7.1
The bq27620-G1 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 first 8-bits of the I2C protocol will; therefore, be 0xAA or 0xAB for
write or read, respectively.
Host generated
S
ADDR[6:0]
0 A
Gauge 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).
The “quick read” returns data at the address indicated by the address pointer. The address pointer, a
register internal to the I2C communication engine, will increment whenever data is acknowledged by the
bq27620-G1 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):
Attempt to read an address above 0x6B (NACK command):
7.2
I2C Time Out
The I2C engine will release both SDA and SCL if the I2C bus is held low for 2 seconds. If the bq27620-G1
was holding the lines, releasing them will free them 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.
COMMUNICATIONS
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7.3
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I2C Command Waiting Time
To ensure proper operation at 400 kHz, a t(BUF) ≥ 66 μs bus free waiting time should be inserted between
all packets addressed to the bq27620-G1 . In addition, if the SCL clock frequency (fSCL) is > 100 kHz, use
individual 1-byte write commands for proper data flow control. The following diagram shows the standard
waiting time required between issuing the control subcommand the reading the status result. For readwrite 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.
S
ADDR [6:0]
0 A
CMD [7:0]
A
DATA [7:0]
A P
66ms
S
ADDR [6:0]
0 A
CMD [7:0]
A
DATA [7:0]
A P
66ms
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
66ms
N P
66ms
Waiting time inserted between two 1-byte write packets for a subcommand and reading results
(required for 100 kHz < fSCL £ 400 kHz)
S
ADDR [6:0]
0 A
CMD [7:0]
A
DATA [7:0]
S
ADDR [6:0]
0 A
CMD [7:0]
A Sr
ADDR [6:0]
A
1 A
DATA [7:0]
A P
DATA [7:0]
A
66ms
DATA [7:0]
Waiting time inserted between incremental 2-byte write packet for a subcommand and reading results
(acceptable for fSCL £ 100 kHz)
S
ADDR [6:0]
DATA [7:0]
0 A
A
CMD [7:0]
DATA [7:0]
A Sr
N P
ADDR [6:0]
1 A
DATA [7:0]
A
DATA [7:0]
A
66ms
Waiting time inserted after incremental read
7.4
I2C Clock Stretching
A clock stretch can occur during all modes of fuel gauge operation. In SLEEP and HIBERNATE modes, a
short clock stretch will occur on all I2C traffic as the device must wake-up to process the packet. In the
other modes ( BAT INSERT CHECK , NORMAL) clock stretching will only occur for packets addressed for
the fuel gauge. The majority of clock stretch periods are small as the I2C interface performs normal data
flow control. However, less frequent yet more significant clock stretch periods may occur as blocks of Data
Flash are updated. The following table summarizes the approximate clock stretch duration for various fuel
gauge operating conditions.
Approximate
Duration
Gauging Mode
Operating Condition / Comment
SLEEP
HIBERNATE
Clock stretch occurs at the beginning of all traffic as the device wakes up.
≤ 4 ms
BAT INSERT
CHECK
NORMAL
Clock stretch occurs within the packet for flow control. (after a start bit, ACK or first data bit)
≤ 4 ms
Normal Ra table Data Flash updates.
24 ms
Data Flash block writes.
72 ms
Restored Data Flash block write after loss of power.
116 ms
End of discharge Ra table Data Flash update.
144 ms
38
COMMUNICATIONS
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8 REFERENCE SCHEMATICS
8.1
SCHEMATIC
REFERENCE SCHEMATICS
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39
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)
BQ27620YZFR-G1
ACTIVE
DSBGA
YZF
15
3000
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-40 to 85
BQ27620G
BQ27620YZFT-G1
ACTIVE
DSBGA
YZF
15
250
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-40 to 85
BQ27620G
(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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