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bq27621-G1
SLUSBB3E – DECEMBER 2013 – REVISED JANUARY 2016
bq27621-G1 System-Side Fuel Gauge With Dynamic Voltage Correlation
1 Features
3 Description
•
The Texas Instruments bq27621-G1 is a minimally
configured microcontroller peripheral that provides
system-side fuel gauging for single-cell Li-Ion
batteries. The device requires very little user
configuration and system microcontroller firmware
development.
1
•
•
•
•
Single-Cell Li-Ion Battery Fuel Gauge
– Resides on System Board
– Supports Embedded or Removable Batteries
– Powered Directly from Battery with Integrated
LDO
Easy To Configure Fuel Gauging Based on the
Dynamic Voltage Correlation Algorithm
– Reports Remaining Capacity and State of
Charge (SOC) with Smoothing Filter
– Automatically Adjusts for Self-Discharge,
Temperature, and Rate Changes
Microcontroller Peripheral Supports:
– 400-kHz I2C Serial Interface
– Configurable SOC Interrupt or
Battery Low Digital Output Warning
– Internal Temperature Sensor or
Host Reported Temperature
Support 4.2-V, 4.3-V, and 4.35-V Chemistries
9-pin 1.62 × 1.58 mm, 0.5 mm pitch YZF package
Battery fuel gauging with the bq27621-G1 requires
connections only to PACK+ (P+) and PACK– (P–) for
a removable battery pack or embedded battery
circuit. The tiny 9-pin, 1.62 mm × 1.58 mm, 0.5 mm
pitch YZF package is ideal for space-constrained
applications.
Device Information(1)
PART NUMBER
BQ27621-G1
PACKAGE
YZF (9)
BODY SIZE (NOM)
1.62 mm × 1.58 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
2 Applications
•
•
•
•
The bq27621-G1 uses the Dynamic Voltage
Correlation algorithm for fuel gauging. This process
eliminates the need for a sense resistor when
calculating remaining battery capacity (mAh), stateof-charge (%), battery voltage (mV), and temperature
(°C).
Smartphones, Feature Phones, and Tablets
Digital Still and Video Cameras
Handheld Terminals
MP3 or Multimedia Players
Simplified Schematic
I2C
Bus
Battery Pack
SCL
BAT
ADC
SDA
PACKP
Li-Ion
Cell
CPU
T
GPOUT
BIN
VDD
1.8 V
LDO
0.47 µF
VSS
1 µF
PACKN
Protection
IC
NFET NFET
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
bq27621-G1
SLUSBB3E – DECEMBER 2013 – REVISED JANUARY 2016
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Device Comparison Table.....................................
Pin Configurations and Functions .......................
Specifications.........................................................
1
1
1
2
3
3
4
7.1
7.2
7.3
7.4
7.5
7.6
7.7
4
4
4
4
4
5
Absolute Maximum Ratings ......................................
ESD Ratings ............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Supply Current ..........................................................
Digital Input and Output DC Characteristics .............
LDO Regulator, Wake-up, and Auto-Shutdown DC
Characteristics ...........................................................
7.8 ADC (Temperature and Cell Measurement)
Characteristics ...........................................................
7.9 I2C-Compatible Interface Communication Timing
Characteristics ...........................................................
7.10 Typical Characteristics ............................................
8
8.1
8.2
8.3
8.4
8.5
9
Overview ...................................................................
Functional Block Diagram .........................................
Feature Description...................................................
Device Functional Modes..........................................
Programming.............................................................
8
8
9
9
9
Application and Implementation ........................ 14
9.1 Application Information............................................ 14
9.2 Typical Application ................................................. 14
10 Power Supply Recommendations ..................... 16
10.1 Power Supply Decoupling ..................................... 16
11 Layout................................................................... 17
11.1 Layout Guidelines ................................................. 17
11.2 Layout Example .................................................... 17
12 Device and Documentation Support ................. 18
5
5
5
7
Detailed Description .............................................. 8
12.1
12.2
12.3
12.4
12.5
Documentation Support ........................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
18
18
18
18
18
13 Mechanical, Packaging, and Orderable
Information ........................................................... 18
4 Revision History
Changes from Revision D (December 2014) to Revision E
Page
•
Changed Pin Configurations and Functions .......................................................................................................................... 3
•
Added Community Resources ............................................................................................................................................. 18
•
Changed Mechanical, Packaging, and Orderable Information ............................................................................................ 18
Changes from Revision C (March 2014) to Revision D
Page
•
Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation
section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and
Mechanical, Packaging, and Orderable Information section ................................................................................................. 1
•
Changed Typical Application to Simplified Schematic and added 1-µF capacitor ................................................................. 1
•
Added description for connecting 1-µF capacitor .................................................................................................................. 3
•
Added information for connecting GPOUT ............................................................................................................................ 3
Changes from Revision B (January 2014) to Revision C
Page
•
Updated command list and algorithm descriptions................................................................................................................. 1
•
Updated BIN pin description .................................................................................................................................................. 3
•
Updated GPOUT pin description ........................................................................................................................................... 3
•
Changed recommend to required......................................................................................................................................... 17
2
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SLUSBB3E – DECEMBER 2013 – REVISED JANUARY 2016
5 Device Comparison Table
PART NUMBER
bq27621YZFR-G1
(1)
(2)
(3)
BATTERY
TYPE
CHEM_ID
LiCoO2
(4.2 V maximum charge)
0x1202
LiCoO2
(4.3 V maximum charge)
0x1210
LiCoO2
(4.35 V maximum charge)
0x354
(1)
FIRMWARE
VERSION (2)
1.05
(0x0105)
PACKAGE
(3)
COMMUNICATION
FORMAT
CSP-9
I2C
See the CHEM_ID subcommand to confirm the battery chemistry type. See Alternate Chemistry Selection to select different chemistries.
See the FW_VERSION subcommand to confirm the firmware version.
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.
6 Pin Configurations and Functions
(TOP VIEW)
(BOTTOM VIEW)
C3
C2
C1
C1
C2
C3
B3
B2
B1
B1
B2
B3
A3
A2
A1
A1
A2
A3
Pin A1
Index Area
Pin Functions
PIN
NAME
BAT
NO.
C2, C3
BIN
B1
TYPE (1)
PI, AI
DESCRIPTION
LDO regulator input and battery voltage input. Connect to positive battery connector. For highest accuracy, use a Kelvin
connection by directly routing to the PACK+ pin and minimizing current flow through the trace. Connect a capacitor (1 µF)
between BAT and VSS. Place the capacitor close to gauge.
DI
Battery insertion detection input. If Operation Configuration bit [BIE] = 1 (default), a logic low on the pin is detected as
battery insertion. For a removable pack, the BIN pin can be connected to VSS through a pulldown resistor on the pack,
typically the 10-kΩ thermistor; the system board should use a 1.8-MΩ pullup resistor to VDD to ensure the BIN pin is high
when a battery is removed. If the battery is embedded in the system, it is recommended to leave [BIE] = 1 and use a 10-kΩ
pulldown resistor from BIN to VSS. If [BIE] = 0, then the host must inform the gauge of battery insertion and removal with the
BAT_INSERT and BAT_REMOVE subcommands. A 10-kΩ pulldown resistor should be placed between BIN and VSS, even if
this pin is unused.
NOTE: The BIN pin must not be shorted directly to VCC or VSS and any pullup resistor on the BIN pin must be connected only
to the bq27621 VDD and not an external voltage rail.
GPOUT
A1
DO
This open-drain output can be configured to indicate BAT_LOW when the Operation Configuration [BATLOWEN] bit is set.
By default [BATLOWEN] is cleared and this pin performs an interrupt function (SOC_INT) by pulsing for specific events, such
as a change in State of Charge. Signal polarity for these functions is controlled by the [GPIOPOL] configuration bit. This pin
should not be left floating, even if unused, so a 10-kΩ pullup resistor is recommended. If the device is in shutdown mode,
then toggling GPOUT will make the gauge exit shutdown. Therefore, it is recommended to connect GPOUT to a GPIO of the
host MSU.
SCL
A3
DIO
Slave I2C serial communications clock input line for communication with system (Master). Use with 10-kΩ pullup resistor
(typical).
SDA
A2
DIO
Slave I2C serial communications data line for communication with system (Master). Open-drain I/O. Use with 10-kΩ pullup
resistor (typical).
VDD
B3
PO
1.8-V Regulator Output. Decouple with 0.47-μF ceramic capacitor to VSS.
VSS
B2, C1
PI
Ground pins. B2 is the actual device ground pin while C1 is floating internally. Therefore, C1 may be used as a bridge to
connect to the board ground plane without requiring a via under the device package. Recommend routing B2 to C1 using a
top-layer metal trace on the board. Connect to negative battery connector. For highest accuracy, use a Kelvin connection by
directly routing to the PACK– pin and minimizing current flow through the trace.
(1)
IO = Digital input-output, IA = Analog input, P = Power connection
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7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
MAX
VBAT
BAT pin input voltage range
PARAMETER
–0.3
6
V
VDD
VDD pin supply voltage range (LDO output)
–0.3
2
V
VIOD
Open-drain I/O pins (SDA, SCL, GPOUT)
–0.3
6
V
VIOPP
Push-Pull I/O pins (BIN)
–0.3
[VDD + 0.3]
V
TA
Operating free-air temperature range
–40
85
°C
Tstg
Storage temperature
–65
150
°C
(1)
UNIT
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.
7.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±1000
Charged-device model (CDM), per JEDEC specification JESD22C101 (2)
±250
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
7.3 Recommended Operating Conditions
TA = 30°C and VREGIN = VBAT = 3.6 V (unless otherwise noted)
PARAMETER
CBAT (1)
CLDO18
VPU
(1)
TEST CONDITIONS
Optional external input capacitor for
internal LDO between BAT and VSS
(1)
External output capacitor for internal
LDO between VDD and VSS
Nominal capacitor values specified.
Recommend a 5% ceramic X5R type
capacitor located close to the device.
External pullup voltage for open-drain
pins (SDA, SCL, GPOUT)
(1)
MIN
NOM
MAX
UNIT
0.1
μF
0.47
μF
1.62
3.6
V
Specified by design. Not production tested.
7.4 Thermal Information
bq27621-G1
THERMAL METRIC
(1)
YZF (DSBGA)
UNIT
9 PINS
RθJA
Junction-to-ambient thermal resistance
107.8
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
0.7
°C/W
RθJB
Junction-to-board thermal resistance
60.4
°C/W
ψJT
Junction-to-top characterization parameter
3.5
°C/W
ψJB
Junction-to-board characterization parameter
60.4
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
n/a
°C/W
(1)
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics Application Report, SPRA953.
7.5 Supply Current
TA = 30°C and VREGIN = VBAT = 3.6 V (unless otherwise noted)
PARAMETER
ICC
ISLP
(1)
4
(1)
(1)
TEST CONDITIONS
MIN
TYP
MAX
UNIT
NORMAL mode current
ILOAD > Sleep Current
27
μA
SLEEP mode current
ILOAD < Sleep Current
21
μA
Specified by design. Not production tested.
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Supply Current (continued)
TA = 30°C and VREGIN = VBAT = 3.6 V (unless otherwise noted)
PARAMETER
(1)
IHIB
ISD
(1)
TEST CONDITIONS
HIBERNATE mode current
ILOAD < Hibernate Current
SHUTDOWN mode current
Fuel gauge in host commanded
SHUTDOWN mode.
(LDO Regulator Output Disabled)
MIN
TYP
MAX
UNIT
9
μA
0.6
μA
7.6 Digital Input and Output DC Characteristics
TA = –40°C to 85°C, typical values at TA = 30°C and VREGIN = 3.6 V (unless otherwise noted)(Force Note1) (1)
PARAMETER
VIH(OD)
(2)
Input voltage, high
TYP
V
0.6
V
0.5
mA
–3
mA
5
pF
IOH
Output source current, high
IOL(OD)
Output sink current, low
(1)
(2) (3)
(2)
(2)
Input leakage current
(SCL, SDA, BIN)
0.1
Input leakage current (GPOUT)
(1)
(2)
(3)
UNIT
0.6
Output voltage, low
Ilkg
MAX
(2)
Input voltage, low
VOL
Input capacitance
MIN
VPU × 0.7
(2) (3)
VIL
CIN
TEST CONDITIONS
External pullup resistor to VPU
V
μA
1
Specified by design. Not production tested.
Open drain pins: (SCL, SDA, GPOUT)
Push-pull pin: (BIN)
7.7 LDO Regulator, Wake-up, and Auto-Shutdown DC Characteristics
TA = –40°C to 85°C, typical values at TA = 30°C and VREGIN = 3.6 V (unless otherwise noted)(Force Note1) (1)
PARAMETER
VBAT
BAT pin regulator input
VDD
Regulator output voltage
UVLOIT+
VBAT Undervoltage Lock Out
LDO Wake-Up Rising Threshold
UVLOIT–
VBAT Undervoltage Lock Out
LDO Auto-Shutdown Falling
Threshold
(1)
TEST CONDITIONS
MIN
TYP
2.45
MAX
4.5
UNIT
V
1.8
V
2
V
1.95
V
Specified by design. Not production tested.
7.8 ADC (Temperature and Cell Measurement) Characteristics
TA = –40°C to 85°C; typical values at TA = 30°C and VREGIN = 3.6 V (unless otherwise noted) (Force Note1) (1)
PARAMETER
VIN(BAT)
BAT pin voltage measurement
range.
tADC_CONV
Conversion time
TEST CONDITIONS
Voltage divider enabled.
MIN
TYP
2.45
4.5
Effective Resolution
(1)
MAX
UNIT
V
125
ms
15
bits
Specified by design. Not tested in production.
7.9 I2C-Compatible Interface Communication Timing Characteristics
TA = –40°C to 85°C; typical values at TA = 30°C and VREGIN = 3.6 V (unless otherwise noted) (Force Note1) (1)
PARAMETER
TEST CONDITIONS
MIN
NOM
MAX
UNIT
Standard Mode (100 kHz)
td(STA)
(1)
Start to first falling edge of SCL
4
µs
Specified by design. Not production tested.
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I2C-Compatible Interface Communication Timing Characteristics (continued)
TA = –40°C to 85°C; typical values at TA = 30°C and VREGIN = 3.6 V (unless otherwise noted) (Force Note1)(1)
PARAMETER
TEST CONDITIONS
tw(L)
SCL pulse duration (low)
tw(H)
SCL pulse duration (high)
tsu(STA)
Setup for repeated start
tsu(DAT)
Data setup time
th(DAT)
Data hold time
tsu(STOP)
Setup time for stop
t(BUF)
Bus free time between stop and
start
tf
SCL/SDA fall time
tr
SCL/SDA rise time
fSCL
Clock frequency
MIN
NOM
MAX
UNIT
4.7
µs
4
µs
4.7
µs
Host drives SDA
250
ns
Host drives SDA
0
ns
4
µs
66
µs
Includes Command Waiting Time
(1)
(1)
(2)
300
ns
300
ns
100
kHz
Fast Mode (400 kHz)
td(STA)
Start to first falling edge of SCL
600
ns
tw(L)
SCL pulse duration (low)
1300
ns
tw(H)
SCL pulse duration (high)
600
ns
tsu(STA)
Setup for repeated start
600
ns
tsu(DAT)
Data setup time
Host drives SDA
100
ns
th(DAT)
Data hold time
Host drives SDA
tsu(STOP)
Setup time for stop
t(BUF)
Bus free time between stop and
start
tf
SCL/SDA fall time
tr
SCL/SDA rise time
fSCL
Clock frequency (2)
(2)
Includes Command Waiting Time
0
ns
600
ns
66
µs
(1)
300
(1)
ns
300
ns
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 I2C Interface and I2C Command Waiting Time).
tSU(STA)
tw(H)
tf
tw(L)
tr
t(BUF)
SCL
SDA
td(STA)
tf
tr
th(DAT)
tsu(STOP)
tsu(DAT)
REPEATED
START
STOP
START
Figure 1. I2C-Compatible Interface Timing Diagrams
6
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7.10 Typical Characteristics
10
0.14
0.12
0.1
Voltage Accuracy Error (%)
Temperature Accuracy Error(%)
5
0
-5
0.08
0.06
-10
0.04
-15
-40
-20
0
20
40
Temperature (°C)
60
80
100
0.02
-40
-20
Figure 2. Voltage Accuracy
0
20
40
Temperature (°C)
60
80
100
Figure 3. Temperature Accuracy
0
-0.1
Current Accuracy Error (%)
-0.2
-0.3
-0.4
-0.5
-0.6
-40
-20
0
20
40
Temperature (°C)
60
80
100
Figure 4. Current Accuracy
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8 Detailed Description
8.1 Overview
The bq27621-G1 battery fuel gauge accurately predicts the battery capacity and other operational characteristics
of a single Li-based rechargeable cell. It can be interrogated by a system processor to provide cell information
such as State of Charge (%) and Remaining Capacity (mAh). The device is preconfigured with three battery
profiles. The default profile is for standard LiCoO2-based batteries with a maximum charge voltage of 4.2 V. The
other two profiles that can be selected via I2C commands are for batteries with charging voltages of 4.3 V and
4.35 V.
Unlike some other fuel gauges, the bq27621-G1 fuel gauge cannot be programmed with specific battery
chemistry profiles. For many battery types and applications, the predefined standard chemistry profiles available
in the bq27621-G1 fuel gauge are sufficient matches from a gauging perspective.
NOTE
Formatting conventions used in this document:
Commands: italics with
RemainingCapacity()
parentheses
and
no
breaking
spaces,
for
example:
Data Memory Configuration Parameter: italics, bold, and breaking spaces, for example:
Design Capacity
Register bits and flags: brackets and italics, for example: [ITPOR]
Data Memory Configuration Parameter bits: brackets, italics and bold, for example: [BIE]
Modes and states: ALL CAPITALS, for example: UNSEALED mode
8.2 Functional Block Diagram
I2C
Bus
Battery Pack
SCL
BAT
ADC
SDA
PACKP
Li-Ion
Cell
CPU
T
GPOUT
BIN
8
VDD
1.8 V
LDO
0.47 µF
VSS
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1 µF
PACKN
Protection
IC
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8.3 Feature Description
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 control and status registers, as well as
its data locations. Commands are sent from system to gauge using the I2C serial communications engine, and
can be executed during application development, system manufacture, or end-equipment operation.
The key to the fuel gauging prediction of the bq27621-G1 fuel gauge is Texas Instruments proprietary Dynamic
Voltage Correlation algorithm. This algorithm eliminates the need for a sense resistor when calculating remaining
battery capacity (mAh) and state-of-charge (%). This algorithm uses cell voltage measurements and cell
characteristics to create state-of-charge predictions that can achieve high accuracy across a wide variety of
operating conditions.
The fuel gauge estimates charge and discharge activity by monitoring the cell voltage. Cell impedance is
computed based on estimated current, open-circuit voltage (OCV), and cell voltage under loaded conditions.
The fuel gauge uses an integrated temperature sensor for estimating cell temperature. Alternatively, the system
processor can provide temperature data for the fuel gauge.
8.4 Device Functional Modes
To minimize power consumption, the fuel gauge has several power modes: INITIALIZATION, NORMAL, SLEEP,
HIBERNATE, and SHUTDOWN. The fuel gauge passes automatically between these modes, depending upon
the occurrence of specific events, though a system processor can initiate some of these modes directly.
The gauge can be configured and used in a matter of minutes by following the Quickstart Guide for bq27621-G1
(SLUUAP5). The information in that document is sufficient for most applications. For further customization and
options, more exhaustive details can be found in the bq27621-G1 Technical Reference Manual (SLUUAD4).
8.5 Programming
8.5.1 Data Commands
8.5.1.1 Standard Data Commands
The bq27621-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 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 details are
found in the bq27621-G1 Technical Reference Manual (SLUUAD4).
NOTE
Data values read by the host may be invalid during initialization for a period of up to 3
seconds.
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Table 1. Standard Commands
NAME
UNIT
SEALED ACCESS
Control()
CNTL
0x00 and 0x01
NA
R/W
Temperature()
TEMP
0x02 and 0x03
0.1°K
R/W
Voltage()
VOLT
0x04 and 0x05
mV
R
FLAGS
0x06 and 0x07
NA
R
NominalAvailableCapacity()
0x08 and 0x09
mAh
R
FullAvailableCapacity()
0x0A and 0x0B
mAh
R
Flags()
RemainingCapacity()
RM
0x0C and 0x0D
mAh
R
FullChargeCapacity()
FCC
0x0E and 0x0F
mAh
R
EffectiveCurrent()
0x10 and 0x11
mA
R
AveragePower()
0x18 and 0x19
mW
R
0x1C and 0x1D
%
R
InternalTemperature()
0x1E and 0x1F
0.1°K
R
RemainingCapacityUnfiltered()
0x28 and 0x29
mAh
R
RemainingCapacityFiltered()
0x2A and 0x2B
mAh
R
FullChargeCapacityUnfiltered()
0x2C and 0x2D
mAh
R
FullChargeCapacityFiltered()
0x2E and 0x2F
mAh
R
StateOfChargeUnfiltered()
0x30 and 0x31
mAh
R
OperationConfiguration()
0x3A and 0x3B
NA
R
StateOfCharge()
10
COMMAND
CODE
SOC
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8.5.1.2
SLUSBB3E – DECEMBER 2013 – REVISED JANUARY 2016
Control(): 0x00 and 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
fuel gauge during normal operation and additional features when the device is in different access modes.
Additional details are found in the bq27621-G1 Technical Reference Manual (SLUUAD4).
Table 2. Control() Subcommands
CNTL DATA
SEALED ACCESS
CONTROL_STATUS
CNTL FUNCTION
0x0000
Yes
Reports the status of device.
DESCRIPTION
DEVICE_TYPE
0x0001
Yes
Reports the device type (0x0621).
FW_VERSION
0x0002
Yes
Reports the firmware version of the device.
PREV_MACWRITE
0x0007
Yes
Returns previous MAC command code.
CHEM_ID
0x0008
Yes
Reports the chemical identifier of the battery profile currently used by the
fuel gauging algorithm
BAT_INSERT
0x000C
Yes
Forces the [BAT_DET] bit set when the [BIE] bit is 0.
BAT_REMOVE
0x000D
Yes
Forces the [BAT_DET] bit clear when the [BIE] bit is 0.
TOGGLE_POWERMIN
0x0010
Yes
Set CONTROL_STATUS [POWERMIN] to 1.
SET_HIBERNATE
0x0011
Yes
Forces CONTROL_STATUS [HIBERNATE] to 1.
CLEAR_HIBERNATE
0x0012
Yes
Forces CONTROL_STATUS [HIBERNATE] to 0.
SET_CFGUPDATE
0x0013
No
Force CONTROL_STATUS [CFGUPMODE] to 1 and gauge enters
CONFIG UPDATE mode.
SHUTDOWN_ENABLE
0x001B
No
Enables device SHUTDOWN mode.
SHUTDOWN
0x001C
No
Commands the device to enter SHUTDOWN mode.
SEALED
0x0020
No
Places the device in SEALED access mode.
TOGGLE_GPOUT
0x0023
Yes
Test the GPIO pin by sending a pulse signal
ALT_CHEM1
0x0031
No
Selects alternate chemistry 1 (0x1210)
ALT_CHEM2
0x0032
No
Selects alternate chemistry 2 (0x354)
RESET
0x0041
No
Performs a full device reset.
SOFT_RESET
0x0042
No
Gauge exits CONFIG UPDATE mode.
EXIT_CFGUPDATE
0x0043
No
Exits CONFIG UPDATE mode without an OCV measurement and
without resimulating to update StateOfCharge().
EXIT_RESIM
0x0044
No
Exits CONFIG UPDATE mode without an OCV measurement and
resimulates with the updated configuration data to update
StateOfCharge().
8.5.2 Alternate Chemistry Selection
The fuel gauge allows the user to change the chemistry settings using I2C commands. The default chemistry has
a CHEM_ID of 0x1202. The two other CHEM_IDs supported by this device includes CHEM_ID 0x1210 and
CHEM_ID 0x354. The detailed procedure to change the chemistry is available in the bq27621-G1 Technical
Reference Manual (SLUUAD4).
8.5.3 Communications
8.5.3.1 I2C Interface
The bq27621-G1 fuel gauge 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 are, therefore, 0xAA or 0xAB for write or read,
respectively.
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Host generated
S
ADDR[6:0]
0 A
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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).
Figure 5. I2C Format
The quick read returns data at the address indicated by the address pointer. The address pointer, a register
internal to the I2C communication engine, increments whenever data is acknowledged by the fuel gauge or the
I2C master. The 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:
Figure 6. Attempt To Write a Read-only Address (Nack After Data Sent By Master)
Figure 7. Attempt To Read an Address Above 0x6B (Nack Command)
8.5.3.2 I2C Time Out
The I2C engine releases both SDA and SCL if the I2C bus is held low for 2 seconds. If the fuel gauge is holding
the lines, releasing them frees them for the master to drive the lines.
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8.5.3.3 I2C Command Waiting Time
To ensure proper operation at 400 kHz, a t(BUF) ≥ 66 µs bus-free waiting time must be inserted between all
packets addressed to the fuel gauge. In addition, if the SCL clock frequency (fSCL) is > 100 kHz, use individual 1byte 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 read-write standard
command, a minimum of 2 seconds is required to get the result updated. For read-only standard commands,
there is no waiting time required, but the host must not issue any standard command 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
Figure 8. I2C Command Wait Time
8.5.3.4 I2C Clock Stretching
A clock stretch of up to 4 ms can occur during all modes of fuel gauge operation. In SLEEP and HIBERNATE
modes, a short clock stretch occurs on all I2C traffic as the device must wake-up to process the packet. In the
other modes (INITIALIZATION, NORMAL) clock stretching only occurs for packets addressed for the fuel gauge.
The majority of clock stretch periods are small as the I2C interface performs normal data flow control.
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9 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
The Texas Instruments bq27621-G1 fuel gauge accurately predicts the battery capacity and other operational
characteristics of a single Li-base rechargeable cell.
9.2 Typical Application
Figure 9. Reference (EVM) Schematic
9.2.1 Design Requirements
The bq27621-G1 fuel gauge is predefined for LiCoO2-based batteries, which have 4.2-V, 4.3-V, and 4.35-V
maximum charging voltages. One orderable part number contains three different battery profiles, which can be
selected using I2C commands. Please refer to the bq27621-G1 Technical Reference Manual (SLUUAD4) for the
procedure to select alternate chemistry profiles.
9.2.2 Detailed Design Procedure
9.2.2.1 BAT Voltage Sense Input
A ceramic capacitor at the input to the BAT pin is used to bypass AC voltage ripple to ground, greatly reducing
its influence on battery voltage measurements. It proves most effective in applications with load profiles that
exhibit high-frequency current pulses (that is, cell phones) but is recommended for use in all applications to
reduce noise on this sensitive high-impedance measurement node.
9.2.2.2 Integrated LDO Capacitor
The fuel gauge has an integrated LDO with an output on the VDD pin of approximately 1.8 V. A capacitor of
value at least 0.47 μF should be connected between the VDD pin and VSS. The capacitor should be placed
close to the gauge IC and have short traces to both the VDD pin and VSS.
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Typical Application (continued)
9.2.3 Application Curves
10
0.14
0.12
0.1
Voltage Accuracy Error (%)
Temperature Accuracy Error(%)
5
0
-5
0.08
0.06
-10
0.04
-15
-40
-20
0
20
40
Temperature (°C)
60
80
100
0.02
-40
-20
Figure 10. Voltage Accuracy
0
20
40
Temperature (°C)
60
80
100
Figure 11. Temperature Accuracy
0
-0.1
Current Accuracy Error (%)
-0.2
-0.3
-0.4
-0.5
-0.6
-40
-20
0
20
40
Temperature (°C)
60
80
100
Figure 12. Current Accuracy
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10 Power Supply Recommendations
10.1 Power Supply Decoupling
The battery connection on the BAT pin is used for two purposes: • To supply power to the fuel gauge • As an
input for voltage measurement of the battery A capacitor of value of at least 1 μF should be connected between
BAT and VSS. The capacitor should be placed close to the gauge IC and have short traces to both the BAT pin
and VSS. The fuel gauge has an integrated LDO with an output on the VDD pin of approximately 1.8 V. A
capacitor of value at least 0.47 μF should be connected between the VDD pin and VSS. The capacitor should be
placed close to the gauge IC and have short traces to both the VDD pin and VSS.
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11 Layout
11.1 Layout Guidelines
•
A capacitor, of value at least 0.47 µF, is connected between the VDD pin and VSS. The capacitor should be
placed close to the gauge IC and have short traces to both the VDD pin and VSS.
It is required to have a capacitor, at least 1.0 µF, connected between the BAT pin and VSS if the connection
between the battery pack and the gauge BAT pin has the potential to pick up noise. The capacitor should be
placed close to the gauge IC and have short traces to both the VDD pin and VSS.
If the external pullup resistors on the SCL and SDA lines will be disconnected from the host during low-power
operation, it is recommend to use external 1-MΩ pulldown resistors to VSS to avoid floating inputs to the I2C
engine.
The value of the SCL and SDA pullup resistors should take into consideration the pullup voltage and the bus
capacitance. Some recommended values, assuming a bus capacitance of 10 pF, can be seen in Table 3.
•
•
•
Table 3. Recommended Values for SCL and SDA Pullup Resistors
VPU
1.8 V
RPU
•
3.3 V
Range
Typical
Range
Typical
400 Ω ≤ RPU ≤ 37.6 kΩ
10 kΩ
900 Ω ≤ RPU ≤ 29.2 kΩ
5.1 kΩ
If the GPOUT pin is not used by the host, the pin should still be pulled up to VDD with a 4.7-kΩ or 10-kΩ
resistor.
If the battery pack thermistor is not connected to the BIN pin, the BIN pin should be pulled down to VSS with a
10-kΩ resistor.
The BIN pin should not be shorted directly to VDD or VSS.
The actual device ground is the center pin (B2). The C1 pin is floating internally and can be used as a bridge
to connect the board ground plane to the device ground (B2).
•
•
•
11.2 Layout Example
VSYS
CBAT
BAT
BAT
VSS
Even is GPOUT
is not used by
host, the
GPOUT pin
should be
pulled up
Kelvin connect
the BAT pins
with PACK+
connection on
the battery pack
VDD
VDD
VDD
RSDA
RSCL
Place close
to gauge IC.
Trace to pin
and VSS
should be
short
VSS
BIN
CVDD
RGPOUT
Battery Pack
RBIN
PACK+
SCL
SDA
GPOUT
Li-Ion
Cell
TS
SCL
,I EDWWHU\ SDFN¶V WKHUPLVWRU ZLOO
not be connected to BIN pin, a
10-k pulldown resistor should
be connected to the BIN pin.
SDA
The BIN pin should not be
shorted directly to VDD or VSS.
+
RTHERM
Protection
IC
PACKNFET
NFET
GPOUT
Via connects to Power Ground
Figure 13. Layout Example
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12 Device and Documentation Support
12.1 Documentation Support
12.1.1 Related Documentation
To obtain a copy of any of the following TI documents, call the Texas Instruments Literature Response Center at
(800) 477-8924 or the Product Information Center (PIC) at (972) 644-5580. When ordering, identify this
document by its title and literature number. Updated documents also can be obtained through the TI Web site at
www.ti.com.
1. bq27621-G1 Technical Reference User's Guide (SLUUAD4)
2. bq27621 EVM: Single-Cell Technology User's Guide (SLUUAM6)
3. Quickstart Guide for bq27621-G1 (SLUUAP5)
12.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
12.3 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
12.4 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
12.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
18
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PACKAGE OUTLINE
YZF0009-C01
DSBGA - 0.625 mm max height
SCALE 9.000
DIE SIZE BALL GRID ARRAY
1.65
1.59
B
A
BALL A1
CORNER
1.61
1.55
C
0.625 MAX
SEATING PLANE
0.35
0.15
0.05 C
BALL TYP
1 TYP
0.5 TYP
C
SYMM
B
0.5
TYP
1
TYP
A
0.35
0.25
C A
B
9X
0.015
1
2
3
SYMM
4222180/A 07/2015
NanoFree Is a trademark of Texas Instruments.
NOTES:
1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing
per ASME Y14.5M.
2. This drawing is subject to change without notice.
TM
3. NanoFree package configuration.
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EXAMPLE BOARD LAYOUT
YZF0009-C01
DSBGA - 0.625 mm max height
DIE SIZE BALL GRID ARRAY
(0.5) TYP
9X (
0.245)
2
1
3
A
(0.5) TYP
SYMM
B
C
SYMM
LAND PATTERN EXAMPLE
SCALE:30X
0.05 MAX
( 0.245)
METAL
METAL UNDER
SOLDER MASK
0.05 MIN
( 0.245)
SOLDER MASK
OPENING
SOLDER MASK
OPENING
NON-SOLDER MASK
DEFINED
(PREFERRED)
SOLDER MASK
DEFINED
SOLDER MASK DETAILS
NOT TO SCALE
4222180/A 07/2015
NOTES: (continued)
4. Final dimensions may vary due to manufacturing tolerance considerations and also routing constraints.
For more information, see Texas Instruments literature number SNVA009 (www.ti.com/lit/snva009).
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EXAMPLE STENCIL DESIGN
YZF0009-C01
DSBGA - 0.625 mm max height
DIE SIZE BALL GRID ARRAY
(0.5) TYP
(R0.05) TYP
9X ( 0.25)
1
3
2
A
(0.5)
TYP
SYMM
B
METAL
TYP
C
SYMM
SOLDER PASTE EXAMPLE
BASED ON 0.1 mm THICK STENCIL
SCALE:40X
4222180/A 07/2015
NOTES: (continued)
5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release.
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PACKAGE OPTION ADDENDUM
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10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
BQ27621YZFR-G1A
ACTIVE
DSBGA
YZF
9
3000
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-40 to 85
BQ27621
G1A
BQ27621YZFT-G1A
ACTIVE
DSBGA
YZF
9
250
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-40 to 85
BQ27621
G1A
(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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