BQ27620-G1_技术文档

bq27620-G1

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具有动态电压修正的系统侧 Impedance Track™ 电量计

查询样品: bq27620-G1

1 介绍

1.1 特性

1.2 应用范围

123

• 用于单节串联锂离子应用的电池电量计，此电量计

基于已获专利的 Impedance Track™ 技术且具有动

态电压修正 (IT-DVC) 功能

•

智能电话

数码相机与数码摄像机

手持终端设备

• 驻留在系统主板上

• 无需感测电阻器

MP3 或多媒体播放器

• 由带有集成低压降稳压器 (LDO) 的电池直接供电

• 支持嵌入式或可拆除电池组

• 系统侧电量计提供：

1.3 说明

德州仪器 (TI) bq27620-G1 系统侧是一款易于配置的

微控制器外设，此外设提供针对单节锂离子电池组的电

池电量监测。此器件要求最小用户配置和系统微控制

器固件开发。

– 准确的电池电量监测；针对准确巡航时间预测生

成模拟电池放电曲线

– 可针对电池老化、电池自放电以及温度/速率低效

情况进行自动调节

bq27620-G1 使用已获专利的支持动态电压修正的

Impedance Track™ 算法来进行电量监测。这个已获

专利的工艺在计算剩余电池电量 (mAh)，充电状态

(%)，续航时间（分钟），电池电压 (mV)，温度 (°C)

和电池健康状态时免除了对于感测电阻的需要。

– 支持电池温度报告的内部温度传感器

– 电池电量低时的中断警告

– 电池插入指示器

– 可配置充电状态 (SOC) 中断

– 健康状态指示器

通过 bq27620-G1 进行电池电量监测只需将 PACK+

(P+)，PACK-(P-) 以及热敏电阻 (T) 连接至可拆卸的电

池组或嵌入式电池电路。 CSP 选项采用 2610µm ×

1956µm 15 焊球封装，引线间距为 0.5mm。它是空

间受限应用的理想选择。

– 32 字节非易失性便签闪存

• 400kHz I²C™ 用于与系统微处理器端口相连接的接

口

• 采用 15 引脚 NanoFree™ (CSP) 封装内

典型应用

Host System

Single Cell Li-lon

Battery Pack

VCC

CE

LDO

PACK+

PROTECTION

IC

Voltage

Sense

Battery

Low

Temp

Sense

I2C

DATA

Power

Management

Controller

T

bq27620

CHG

DSG

FETs

PACK-

BAT_GD

SOC_INT

1

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.

2

3

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.

English Data Sheet: SLUSAE3

bq27620-G1

ZHCSAF3 –OCTOBER 2012

www.ti.com.cn

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

介绍 ......................................................... 1

1.1 特性 .................................................. 1

1.2 应用范围 ............................................. 1

1.3 说明 .................................................. 1

DEVICE INFORMATION ................................ 3

2.1 AVAILABLE OPTIONS .............................. 3

2.2 THERMAL INFORMATION .......................... 3

4.2 DATA FLASH INTERFACE ........................ 19

4.3

MANUFACTURER INFORMATION BLOCK ....... 20

4.4 ACCESS MODES .................................. 21

4.5 SEALING/UNSEALING DATA FLASH ............. 21

4.6 DATA FLASH SUMMARY .......................... 22

FUNCTIONAL DESCRIPTION ........................ 26

5.1 FUEL GAUGING ................................... 26

5.2 IMPEDANCE TRACK™ VARIABLES .............. 27

5.3 DETAILED PIN DESCRIPTION .................... 29

5.4 TEMPERATURE MEASUREMENT ................ 34

5.5 OVERTEMPERATURE INDICATION .............. 34

5

2.3

PIN ASSIGNMENT AND PACKAGE DIMENSIONS

4

ELECTRICAL SPECIFICATIONS ..................... 5

3.1 ABSOLUTE MAXIMUM RATINGS .................. 5

3.2

RECOMMENDED OPERATING CONDITIONS ..... 5

5.6

CHARGING AND CHARGE-TERMINATION

3.3 SUPPLY CURRENT ................................. 5

3.4

INDICATION ........................................ 34

DIGITAL INPUT AND OUTPUT DC

CHARACTERISTICS ................................ 6

5.7 POWER MODES ................................... 35

3.5 POWER-ON RESET ................................. 6

3.6 2.5V LDO REGULATOR ............................. 6

3.7 INTERNAL CLOCK OSCILLATORS ................ 6

6

7

APPLICATION-SPECIFIC INFORMATION ......... 36

6.1

BATTERY PROFILE STORAGE AND SELECTION

...................................................... 36

COMMUNICATIONS ................................... 37

7.1 I²C INTERFACE .................................... 37

7.2 I²C Time Out ....................................... 37

7.3 I²C Command Waiting Time ........................ 38

7.4 I²C Clock Stretching ................................ 38

REFERENCE SCHEMATICS ......................... 39

8.1 SCHEMATIC ........................................ 39

3.8

ADC (TEMPERATURE AND CELL

MEASUREMENT) CHARACTERISTICS ............ 7

3.9

DATA FLASH MEMORY CHARACTERISTICS ..... 8

3.10 I²C-COMPATIBLE INTERFACE COMMUNICATION

TIMING CHARACTERISTICS ....................... 8

4

GENERAL DESCRIPTION ............................. 9

8

4.1 DATA COMMANDS ................................ 10

2

内容

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2 DEVICE INFORMATION

2.1 AVAILABLE OPTIONS

FIRMWARE

TAPE and REEL

QUANTITY

PART NUMBER

PACKAGE⁽¹⁾

T_A

COMMUNICATION FORMAT

VERSION⁽¹⁾

bq27620YZFR-G1

1.06

3000

250

I²C

CSP-15

–40°C to 85°C

(0x106)

bq27620YZFT-G1

(1) 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

bq27620-G1

THERMAL METRIC⁽¹⁾

UNITS

YZF(15 PINS)

θ_JA

Junction-to-ambient thermal resistance

70

17

20

1

θ_JCtop

θ_JB

Junction-to-case (top) thermal resistance

Junction-to-board thermal resistance

°C/W

ψ_JT

Junction-to-top characterization parameter

Junction-to-board characterization parameter

Junction-to-case (bottom) thermal resistance

ψ_JB

18

n/a

θ_JCbot

(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953

DEVICE INFORMATION

3

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2.3 PIN ASSIGNMENT AND PACKAGE DIMENSIONS

(TOP VIEW)

(BOTTOM VIEW)

A3

A2

A1

B3

B2

B1

C3

C2

C1

E3

E2

E1

E3

E2

E1

D3

D2

D1

C3

C2

C1

B3

B2

B1

A3

A2

A1

D3

D2

D1

Pin A1

Index Area

D

DIM

MIN

TYP

MAX

2640

1986

UNITS

D

E

2580

1926

2610

1956

ꢀm

Table 2-1. PIN FUNCTIONS

TYPE⁽¹⁾

DESCRIPTION

NAME

NO.

A1, B1,

C1, C2

V_SS

V_CC

P

Device ground

D1

E1

A2

P

O

Regulator output and bq27620-G1 processor power. Decouple with 1μF ceramic capacitor to Vss.

Regulator input. Decouple with 0.1μF ceramic capacitor to Vss.

REGIN

SOC_INT

SOC state interrupts output. Generates a pulse under the conditions specified by Table 5-7. Open drain output. (RA3)

Battery-good indicator. Active-low by default, though polarity can be configured through the [BATG_POL] bit of

Operation Configuration. Push-pull output. (RC1)

BAT_GD

B2

O

CE

D2

E2

I

Chip Enable. Internal LDO is disconnected from REGIN when driven low.

BAT

Cell-voltage measurement input. ADC input. Recommend 4.8V maximum for conversion accuracy. (RC3)

Slave I²C serial communications clock input line for communication with system (Master). Use with 10kΩ pull-up

resistor (typical). (RA2)

SCL

SDA

A3

B3

I

Slave I²C serial communications data line for communication with system (Master). Open-drain I/O. Use with 10kΩ

pull-up resistor (typical). (RA1)

I/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)

BAT_LOW

TS

C3

D3

E3

O

IA

Pack thermistor voltage sense (use 103AT-type thermistor). ADC input. (RC2)

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)

BI/TOUT

I/O

(1) I/O = Digital input/output, IA = Analog input, P = Power connection

4

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3 ELECTRICAL SPECIFICATIONS

3.1 ABSOLUTE MAXIMUM RATINGS

over operating free-air temperature range (unless otherwise noted)⁽¹⁾

PARAMETER

VALUE

–0.3 to 5.5

UNIT

V

V_REGIN

Regulator input range

(2)

–0.3 to 6.0

–0.3 to 2.75

–0.3 to 5.5

V

V_CC

Supply voltage range

V

V_IOD

V_BAT

Open-drain I/O pins (SDA, SCL, SOC_INT )

BAT input pin

V

(2)

–0.3 to 6.0

–0.3 to V_CC+ 0.3

1.5

V

V_I

Input voltage range to all other pins ( BI/TOUT , TS , BAT_GD )

Human-body model (HBM), BAT pin

Human-body model (HBM), all other pins

Operating free-air temperature range

Functional temperature range

V

ESD

kV

2

T_A

–40 to 85

–40 to 100

–65 to 150

°C

T_F

T_stg

Storage temperature range

(1) Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings

only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating

conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2) Condition not to exceed 100 hours at 25 °C lifetime.

3.2 RECOMMENDED OPERATING CONDITIONS

T_A= -40°C to 85°C, V_REGIN= V_BAT= 3.6V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

2.8

TYP

MAX

4.5

UNIT

No operating restrictions

V_REGIN

Supply voltage

V

No FLASH writes

2.45

2.8

External input capacitor for internal

LDO between REGIN and V_SS

C_REGIN

C_LDO25

t_PUCD

0.1

μF

Nominal capacitor values specified.

Recommend a 5% ceramic X5R type

capacitor located close to the device.

External output capacitor for internal

LDO between V_CCand V_SS

0.47

1

μF

Power-up communication delay

250

ms

3.3 SUPPLY CURRENT

T_A= 25°C and V_REGIN= V_BAT= 3.6V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

Normal operating-mode

current⁽¹⁾

Fuel gauge in NORMAL mode.

I_LOAD> Sleep Current

I_CC

118

μA

Low-power storage-mode

current⁽¹⁾

Fuel gauge in SLEEP mode.

I_LOAD< Sleep Current

I_SLP

I_HIB

23

8

μA

Hibernate operating-mode

current⁽¹⁾

Fuel gauge in HIBERNATE mode.

I_LOAD< Hibernate Current

(1) Specified by design. Not production tested.

ELECTRICAL SPECIFICATIONS

5

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3.4 DIGITAL INPUT AND OUTPUT DC CHARACTERISTICS

T_A= –40°C to 85°C, typical values at T_A= 25°C and V_REGIN= 3.6 V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

I_OL= 3 mA

MIN

TYP

MAX

UNIT

Output voltage, low (SCL, SDA,

SOC_INT , BAT_LOW ,

BAT_GD )

V_OL

0.4

V

V_OH(PP)

Output voltage, high

I_OH= –1 mA

V_CC

–

(BAT_LOW , BAT_GD )

0.5

V

Output voltage, high (SDA,

SCL, SOC_INT )

External pullup resistor connected to

V_CC

–

V_OH(OD)

0.5

Input voltage, low (SDA, SCL

pins)

0.6

–0.3

V_IL

Input voltage, low ( BI/TOUT

pin)

BAT INSERT CHECK MODE active

–0.3

1.2

Input voltage, high (SDA, SCL

pins)

V_IH

Input voltage, high ( BI/TOUT

pin)

V_CC

+

BAT INSERT CHECK MODE active

V_REGIN= 2.8 to 4.5V

1.2

0.3

V_IL(CE)

V_IH(CE)

I_lkg

Input voltage, low (CE pin)

0.8

V

V_REGIN

–

Input voltage, high (CE pin)

0.5

Input leakage current (I/O pins)

0.3

μA

(1)

(1) Specified by design. Not production tested.

3.5 POWER-ON RESET

T_A= –40°C to 85°C, typical values at T_A= 25°C and V_REGIN= 3.6 V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

V_IT+

Positive-going battery voltage

input at V_CC

2.05

2.15

2.20

V

V_HYS

Power-on reset hysteresis

45

115

185

mV

3.6 2.5V LDO REGULATOR

T_A= –40°C to 85°C, C_LDO25= 1μF, V_REGIN= 3.6V (unless otherwise noted)

PARAMETER

TEST CONDITION

MIN

NOM

MAX

UNIT

2.8V ≤ V_REGIN≤ 4.5V, I_OUT≤ 16mA

2.45V ≤ V_REGIN< 2.8V (low battery),

2.3

2.5

2.6

V

V_REG25

Regulator output voltage

2.3

V

I_OUT≤ 3mA

3.7 INTERNAL CLOCK OSCILLATORS

T_A= –40°C to 85°C, 2.4 V < V_CC< 2.6 V; typical values at T_A= 25°C and V_CC= 2.5 V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

2.097

MAX

UNIT

MHz

kHz

f_OSC

High Frequency Oscillator

Low Frequency Oscillator

f_LOSC

32.768

6

ELECTRICAL SPECIFICATIONS

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3.8 ADC (TEMPERATURE AND CELL MEASUREMENT) CHARACTERISTICS

T_A= –40°C to 85°C, 2.4 V < V_CC< 2.6 V; typical values at T_A= 25°C and V_CC= 2.5 V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

V_A1

V_A2

Input voltage range (TS )

V_SS

0.125

–

2

V

Input voltage range (BAT)

Input voltage range

V_SS

0.125

–

5

1

V

V_IN(ADC)

G_TEMP

0.05

V

Internal temperature sensor

voltage gain

–2

1

mV/°C

t_{ADC_CONV}

Conversion time

Resolution

125

15

ms

bits

mV

14

V_OS(ADC)

Z_ADC1

Input offset

Effective input resistance

(TS )⁽¹⁾

8

MΩ

bq27620-G1 not measuring cell

voltage

Effective input resistance

(BAT)⁽¹⁾

Z_ADC2

bq27620-G1 measuring cell voltage

100

kΩ

μA

I_lkg(ADC)

Input leakage current⁽¹⁾

0.3

(1) Specified by design. Not tested in production.

ELECTRICAL SPECIFICATIONS

7

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3.9 DATA FLASH MEMORY CHARACTERISTICS

T_A= –40°C to 85°C, 2.4 V < V_CC< 2.6 V; typical values at T_A= 25°C and V_CC= 2.5 V (unless otherwise noted)

PARAMETER

Data retention⁽¹⁾

TEST CONDITIONS

MIN

10

TYP

MAX

UNIT

Years

Cycles

t_DR

Flash-programming write

cycles⁽¹⁾

20,000

t_WORDPROG

I_CCPROG

t_DFERASE

t_IFERASE

Word programming time⁽¹⁾

Flash-write supply current⁽¹⁾

Data flash master erase time⁽¹⁾

2

ms

mA

ms

5

10

200

Instruction flash master erase

time⁽¹⁾

t_PGERASE

Flash page erase time⁽¹⁾

20

ms

(1) Specified by design. Not production tested

3.10 I²C-COMPATIBLE INTERFACE COMMUNICATION TIMING CHARACTERISTICS

T_A= –40°C to 85°C, 2.4 V < V_CC< 2.6 V; typical values at T_A= 25°C and V_CC= 2.5 V (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

300

UNIT

ns

t_r

SCL/SDA rise time

SCL/SDA fall time

t_f

300

ns

t_w(H)

SCL pulse duration (high)

SCL pulse duration (low)

Setup for repeated start

Start to first falling edge of SCL

Data setup time

600

1.3

600

100

0

ns

t_w(L)

μs

ns

t_su(STA)

t_d(STA)

t_su(DAT)

t_h(DAT)

t_su(STOP)

t_(BUF)

ns

Data hold time

ns

Setup time for stop

600

66

ns

Bus free time between stop and

start

μs

(1)

f_SCL

Clock frequency

400

kHz

(1) If the clock frequency (f_SCL) 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 end-

equipment 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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4.1 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

SEALED

ACCESS

NAME

COMMAND CODE

UNITS

Control( )

CNTL

0x00 / 0x01

0x02 / 0x03

0x04 / 0x05

0x06 / 0x07

0x08 / 0x09

0x0a / 0x0b

0x0c / 0x0d

0x0e / 0x0f

0x10 / 0x11

0x12 / 0x13

0x14 / 0x15

0x16 / 0x17

0x18 / 0x19

0x1a / 0x1b

0x1c / 0x1d

0x1e / 0x1f

0x20 / 0x21

0x22 / 0x23

0x24 / 0x25

0x26 / 0x27

0x28 / 0x29

0x2A / 0x2B

0x2c / 0x2d

0x36 / 0x37

0x3A / 0x3B

0x6A / 0x6B

N/A

mA

R/W

R

AtRate( )

AtRateTimeToEmpty( )

Temperature( )

Voltage( )

Minutes

0.1 K

mV

TEMP

VOLT

R/W

R

Flags( )

FLAGS

N/A

R

NominalAvailableCapacity( )

FullAvailableCapacity( )

RemainingCapacity( )

FullChargeCapacity( )

EffectiveCurrent( )

mAh

R

mAh

R

RM

mAh

R

FCC

mAh

R

mA

R

TimeToEmpty( )

Minutes

mA

R

TimeToFull( )

R

StandbyCurrent( )

R

StandbyTimeToEmpty( )

MaxLoadCurrent( )

MaxLoadTimeToEmpty( )

AvailableEnergy( )

AveragePower( )

Minutes

mA

R

Minutes

mWh

mW

R

TTEatConstantPower( )

StateOfHealth( )

Minutes

% / num

num

R

SOH

SOC

R

CycleCount( )

R

StateOfCharge( )

%

R

InternalTemperature( )

OperationConfiguration( )

ApplicationStatus()

0.1 K

N/A

R

N/A

R

10

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4.1.1.1 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

CNTL FUNCTION

DESCRIPTION

CONTROL_STATUS

DEVICE_TYPE

FW_VERSION

HW_VERSION

PREV_MACWRITE

CHEM_ID

0x0000

0x0001

0x0002

0x0003

0x0007

0x0008

0x000c

0x000d

0x000e

0x0011

0x0012

0x001F

0x0020

0x0030

0x0041

Yes

No

Reports the status of DF checksum, hibernate, IT, etc.

Reports the device type in hex digits. (type = 0x0620)

Reports the firmware version on the device type

Reports the hardware version of the device type

Returns previous MAC subcommand code

Reports the chemical identifier of the Impedance Track™ configuration

Request the gauge to take a OCV measurement

Forces the BAT_DET bit set when the [BIE] bit is 0

Forces the BAT_DET bit clear when the [BIE] bit is 0

Forces CONTROL_STATUS [HIBERNATE] to 1

Forces CONTROL_STATUS [HIBERNATE] to 0

Returns the Data Flash Version code

OCV_CMD

BAT_INSERT

BAT_REMOVE

SET_HIBERNATE

CLEAR_HIBERNATE

DF_VERSION

SEALED

Places the bq27620-G1 in SEALED access mode

Sets the OPTIMIZ bit and enables the optimization cycle

Forces a full reset of the bq27620-G1

OPTIMIZ

No

RESET

No

GENERAL 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

bit7

bit6

FAS

bit5

SS

bit4

bit3

-

bit2

-

bit1

OCVCMDCOMP

VOK

bit0

High byte

Low byte

-

RSVD

SLEEP

OCVFAIL

OPTMIZ

INITCOMP

HIBERNATE

RLearn

LDMD

RUP_DIS

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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4.1.1.3 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

bit7

OTC

–

bit6

OTD

–

bit5

–

bit4

bit3

bit2

bit1

FC

bit0

CHG

DSG

High byte

Low byte

CALEN

NEEDID

CHG_INH

BATTDET

XCHG

SOC1

OCVGD

SYSDOWN

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 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.

GENERAL DESCRIPTION

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4.1.1.18 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.

16

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4.1.2 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

SEALED

UNSEALED

NAME

UNITS

ACCESS^{(1) (2)}

Reserved

0x34...0x3b

0x3c / 0x3d

0x3e

N/A

mAh

N/A

R

DesignCapacity( )

DataFlashClass( ) ⁽²⁾

DataFlashBlock( ) ⁽²⁾

BlockData( )

R

N/A

R/W

R

R/W

R

0x3f

0x40…0x5f

0x60

BlockDataCheckSum( )

BlockDataControl( )

ApplicationStatus( )

Reserved

R/W

N/A

R

0x61

0x6a

0x6b...0x7f

R

(1) SEALED and UNSEALED states are entered via commands to Control() 0x00/0x01.

(2) 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.

GENERAL DESCRIPTION

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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 Reserved — 0x6b–0x7f

18

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4.2 DATA FLASH INTERFACE

4.2.1 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.

GENERAL DESCRIPTION

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4.3 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 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

FULL ACCESS

UNSEALED

SEALED

Data Flash

R/W

Manufacture Info Block

R/W

R

R/W

None

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

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4.6 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

Data

Type

Units (EVSW

Units)*

Class

Subclass

Safety

Offset Name

Min Value

Max Value

1200

60

Default Value

Configuration

2

0

2

3

5

7

8

OT Chg

I2

U1

I2

0

550

2

0.1°C

s

OT Chg Time

OT Chg Recovery

OT Dsg

1200

60

500

600

2

0.1°C

s

I2

OT Dsg Time

OT Dsg Recovery

U1

I2

1200

550

0.1°C

Configuration

32

Charge Inhibit Cfg

0

2

4

Chg Inhibit Temp Low

Chg Inhibit Temp High

Temp Hys

I2

-400

0

1200

100

0

0.1°C

450

50

Configuration

34

Charge

0

2

4

6

Charging Voltage

Delta Temp

I2

0

4600

500

4200

50

mV

0

0.1°C

Suspend Low Temp

Suspend High Temp

-400

1200

-50

550

Configuration

36

Charge Termination

0

2

Taper Current

I2

0

1000

60

100

25

mA

mAh

mV

s

Min Taper Capacity

Taper Voltage

4

I2

0

100

40

6

Current Taper Window

FC Set %

U1

I1

0

9

-1

0

100

-1

%

10

11

FC Clear %

I1

100

98

%

DODatEOC Delta T

I2

1000

50

0.1°C

Configuration

48

Data

0

1

Initial Standby

Initial MaxLoad

CC Threshold

Design Capacity

Design Voltage

SOH LoadI

I1

I2

-256

0

-10

-750

mA

-32767

3

I2

100

32767

0

1050

mAh

mA

6

I2

0

1140

10

12

14

16

18

I2

0

-32767

0

3600

MilliVolt

mA

I2

-400

Default Temp

Data Flash Version

Device Name

I2

3050

0xffff

x

2982

°K

H2

S8

0x0000

x

0x0000

bq27620

-

Configuration

49

Discharge

0

1

SOC1 Set Threshold

SOC1 Clear Threshold

SysDown Set Volt Threshold

SysDown Set Volt Time

SysDown Clear Volt

U1

I2

0

255

150

175

3150

2

mA

mV

s

0

5

4200

60

7

U1

I2

0

8

0000

0

4200

16384

32767

3400

0

mV

15

17

19

Def Cell 0 DOD at EOC

Def Avg I Last Run

I2

-32768

-50

mA

Def Avg P Last Run

I2

mWatt

Configuration

64

Registers

0

2

3

4

6

7

8

Op Config

H2

U1

U2

H1

0x0000

0

0xffff

25

0x0853

1

SOC Delta

i2c Timeout

DF Wr Ind Wait

OpConfig B

OpConfig C

Clk Ctl Reg

%

0

7

4

0

65535

0xff

0x0f

0

0x00

0x4b

0x28

0x09

Hex

Configuration

68

Power

0

4

6

Flash Update OK Voltage

Sleep Current

I2

0

4200

100

2800

10

mV

mA

s

Sleep Time

U1

100

20

22

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Table 4-7. Data Flash Summary (continued)

Subclass

ID

Data

Type

Units (EVSW

Units)*

Class

Subclass

Power

Offset Name

Min Value

Max Value

700

Default Value

Configuration

68

7

9

Hibernate I

U2

0

8

mA

Power

Hibernate V

Block [0-31]

U2

2400

3000

2550

mV

System Data

57

Manufacturer Info

0-31

H1

0x00

0xff

[Table]

-

Gas Gauging

80

IT Cfg

0

Load Select

U1

U2

I2

0

255

1

0

1

Load Mode

0

21

22

24

44

46

49

53

55

57

59

64

68

70

72

74

76

83

Max Res Factor

Min Res Factor

Ra Filter

0

255

15

5

0

255

0

1000

32767

4200

65534

-100

800

3200

200

500

0

Terminate Voltage

Term V Delta

-32768

mV

s

I2

0

ResRelax Time

User Rate-mA

User Rate-mW

Reserve Cap-mAh

Reserve Cap-mWh

Min Delta Voltage

Ra Max Delta

U2

I2

0

-2000

mA

cW

I2

-7200

-350

0

I2

0

9000

14000

32000

65535

32767

100

0

mA

10mW

I2

0

I2

-32000

0

U2

U1

0

44

10

5000

200

10

80

mΩ

mV

Num

%

DeltaV Max dV

Max Res Scale

Min Res Scale

Fast Scale Start SOC

LC Dection Sensitivity

100

%

Gas Gauging

81

Current Thresholds

6

8

Dsg Relax Time

U2

U1

U2

0

8191

255

63

60

s

Chg Relax Time

9

Quit Relax Time

1

10

11

12

Transient Factor Charge

Transient Factor Discharge

Max IR Correct

255

1000

128

400

mV

Gas Gauging

82

State

0

1

Host Cfg

H1

I2

0x01

0xff

0x00

Qmax Cell 0

Cycle Count0

Qmax Cell 1

Cycle Count 1

Chg DoD0 C 0

Chg DoD0 C 1

DoDatEOC

0

32767

65535

32767

65535

16384

rate

3

U2

I2

0

5

16384

7

U2

0

9

11

15

25

27

0

T Rise

20

1000

Num

T Time Constant

OCV Table

83

85

OCVa Table

Def Ra

0

Chem ID

H2

H1

0x0000

0x00

0xffff

0x00

0x1124

0x55

hex

-

Default Ra

Tables

Cell0 R_a flag

2^-10

Ω

Default Ra

Tables

85

Def Ra

1

3

Cell0 R_a 0

Cell0 R_a 1

Cell0 R_a 2

Cell0 R_a 3

Cell0 R_a 4

Cell0 R_a 5

Cell0 R_a 6

I2

1

32767

424

509

538

535

461

460

509

Default Ra

Tables

Default Ra

Tables

5

Default Ra

Tables

7

Default Ra

Tables

9

Default Ra

Tables

11

13

Default Ra

Tables

GENERAL DESCRIPTION

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Units (EVSW

Table 4-7. Data Flash Summary (continued)

Subclass

Data

Class

ID

Subclass

Offset Name

Cell0 R_a 7

Type

Min Value

Max Value

Default Value

Units)*

2^-10

Ω

Default Ra

Tables

85

Def Ra

15

17

19

21

23

25

27

29

I2

1

32767

578

Default Ra

Tables

85

Def Ra

Cell0 R_a 8

Cell0 R_a 9

Cell0 R_a 10

Cell0 R_a 11

Cell0 R_a 12

Cell0 R_a 13

Cell0 R_a 14

I2

1

32767

563

Default Ra

Tables

544

Default Ra

Tables

574

Default Ra

Tables

726

Default Ra

Tables

956

Default Ra

Tables

1222

8099

Default Ra

Tables

Ra Table

88

R_a0

0

1

Cell0 R_a flag

Cell0 R_a 0

H1

I2

0x00

1

0x255

32767

0x55

424

-

2^-10

Ω

Ra Table

88

R_a0

3

Cell0 R_a 1

Cell0 R_a 2

Cell0 R_a 3

Cell0 R_a 4

Cell0 R_a 5

Cell0 R_a 6

Cell0 R_a 7

Cell0 R_a 8

Cell0 R_a 9

Cell0 R_a 10

Cell0 R_a 11

Cell0 R_a 12

Cell0 R_a 13

Cell0 R_a 14

I2

1

32767

509

538

535

461

460

509

578

563

544

574

726

956

1222

8099

5

7

9

11

13

15

17

19

21

23

25

27

29

Ra Table

89

R_a1

0

1

Cell1 R_a flag

Cell1 R_a 0

H1

I2

0x00

1

0x255

32767

0x55

424

-

2^-10

Ω

Ra Table

89

R_a1

3

Cell1 R_a 1

Cell1 R_a 2

Cell1 R_a 3

Cell1 R_a 4

Cell1 R_a 5

Cell1 R_a 6

Cell1 R_a 7

Cell1 R_a 8

Cell1 R_a 9

Cell1 R_a 10

Cell1 R_a 11

Cell1 R_a 12

Cell1 R_a 13

Cell1 R_a 14

I2

1

32767

509

538

535

461

460

509

578

563

544

574

726

956

1222

8099

5

7

9

11

13

15

17

19

21

23

25

27

29

Ra Table

90

R_a0x

0

1

xCell0 R_a flag

xCell0 R_a 0

H1

I2

0x00

1

0x255

32767

0x55

424

-

2^-10

Ω

Ra Table

90

R_a0x

3

xCell0 R_a 1

I2

1

32767

509

Ω

24

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Table 4-7. Data Flash Summary (continued)

Subclass

ID

Data

Type

Units (EVSW

Units)*

Class

Subclass

Offset Name

Min Value

Max Value

Default Value

2^-10

Ω

Ra Table

90

R_a0x

5

xCell0 R_a 2

I2

1

32767

538

Ra Table

R_a0x

7

xCell0 R_a 3

xCell0 R_a 4

xCell0 R_a 5

xCell0 R_a 6

xCell0 R_a 7

xCell0 R_a 8

xCell0 R_a 9

xCell0 R_a 10

xCell0 R_a 11

xCell0 R_a 12

xCell0 R_a 13

xCell0 R_a 14

I2

1

32767

535

461

460

509

578

563

544

574

726

956

1222

8099

9

11

13

15

17

19

21

23

25

27

29

Ra Table

91

R_a1x

0

1

xCell1 R_a flag

xCell1 R_a 0

H1

I2

0x00

1

0x255

32767

0x55

424

-

2^-10

Ω

Ra Table

91

R_a1x

3

xCell1 R_a 1

xCell1 R_a 2

xCell1 R_a 3

xCell1 R_a 4

xCell1 R_a 5

xCell1 R_a 6

xCell1 R_a 7

xCell1 R_a 8

xCell1 R_a 9

xCell1 R_a 10

xCell1 R_a 11

xCell1 R_a 12

xCell1 R_a 13

xCell1 R_a 14

I2

1

32767

509

538

535

461

460

509

578

563

544

574

726

956

1222

8099

5

7

9

11

13

15

17

19

21

23

25

27

29

Calibration

104

Data

2

3

4

Int Temp Offset

Ext Temp Offset

Pack V Offset

I1

-128

127

0

Security

112

Codes

0

4

8

Sealed to Unsealed

Unsealed to Full

FactRestore Key

H4

0x0000000

0

0xffffffff

0x00000000

-

0x0000000

0

0x0000000

0

GENERAL DESCRIPTION

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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.

26

FUNCTIONAL DESCRIPTION

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5.2 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

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.

0

Present average discharge current: This is the average discharge current from the beginning of this discharge cycle

until present time.

1(default)

2

3

4

5

6

Average current: based on EffectiveCurrent( )

Current: based off of a low-pass-filtered version of EffectiveCurrent( ) (τ =14 s)

Design capacity / 5: C Rate based off of Design Capacity /5 or a C/5 rate in mA.

AtRate (mA): Use whatever current is in AtRate( )

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

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.

0

Present average discharge power: This is the average discharge power from the beginning of this discharge cycle

until present time.

1(default)

2

3

4

5

6

Average current × voltage: based off the EffectiveCurrent( ) and Voltage( ).

Current × voltage: based off of a low-pass-filtered version of EffectiveCurrent( ) (τ=14 s) and Voltage( )

Design energy / 5: C Rate based off of Design Energy /5 or a C/5 rate in mA.

AtRate (10 mW): Use whatever value is in AtRate( ).

User_Rate-10mW: Use the value in User_Rate-10mW. This mode provides a completely user-configurable method.

5.2.3 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.

FUNCTIONAL DESCRIPTION

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5.2.5 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).

28

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5.3 DETAILED PIN DESCRIPTION

5.3.1 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

bit7

RESCAP

0

bit6

BATG_OVR

0

bit5

INT_BREM

0

bit4

PFC1

0

bit3

PFC2

1

bit2

–

bit1

–

bit0

High Byte

Default =

-

0

0x08

0x73

Low Byte

Default =

INT_FOCV

0

IDSELEN

1

LDODEOC

1

RMFCC

1

SOCPOL

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.

FUNCTIONAL DESCRIPTION

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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

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

Byte

WRTEMP

BIE

BL_INT

GNDSEL

FCE

DFWrIndBL RFACTSTE INDFACRE

P

1

S

1

Default=

0

1

0

1

0

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

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

Byte

BATGSPUE BATGWPU BATLSPUE BATLWPUE

VCCE

–

DeltaVOpt1 DeltaVOpt0

N

0

EN

0

N

1

N

0

Default =

1

0

0x28

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.

30

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Table 5-6. Pin Function Code Summary

External Thermistor Bias Rate

([TEMPS]=1 only)

PFC_CFG

Dis-

BAT_GD pin

PFC

[1:0]

charge

Charge

Sleep

Usage for PFC Pin Function Description

0

0/0

1 / sec

1 / 20

sec

N/A

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.

1

2

3

0/1

1/0

1/1

Temperature-

A dedicated external thermistor is used for the fuel gauge to monitor battery

based Charge temperature in all conditions. If battery charging temperature falls outside of the

Inhibit.

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.

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.

1 / sec

Follows Flags( ) Used to disable a battery charger IC when fuel gauge has determined the battery is

[FC] flags bit.

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_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].

FUNCTIONAL DESCRIPTION

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POR

Exit From HIBERNATE

Battery Removed

Exit From HIBERNATE

Communication Activity

AND Comm address is for bq27520

BAT INSERT CHECK

Check for battery insertion

from HALT state.

No gauging

bq27520 clears Control Status

[HIBERNATE] = 0

Flags [BAT_DET] = 0

Recommend Host also set Control

Status [HIBERNATE] = 0

Entry to NORMAL

Exit From NORMAL

Flags [BAT_DET] = 0

Flags [BAT_DET] = 1

Exit From SLEEP

NORMAL

Flags [BAT_DET] = 0

Fuel gauging and data

updated every1s

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

Entry to SLEEP

Operation Configuration[SLEEP] = 1

AND

Current is Detected above I_WAKE

|

EffectiveCurrent | ≤ Sleep Current

AND

Control Status[SNOOZE] = 0

Exit From WAIT_HIBERNATE

Cell relaxed

AND

| EffectiveCurrent | < Hibernate

Current

WAIT_HIBERNATE

SLEEP

OR

Fuel gauging and data

updated every 20seconds

BAT_GD unchanged

Cell relaxed

AND

V_CELL< Hibernate Voltage

Fuel gauging and data

updated every 20 seconds

(LFO ON and HFO OFF)

Exit From WAIT_HIBERNATE

Host must set Control Status

[HIBERNATE] = 0

AND

V_CELL> Hibernate Voltage

System Shutdown

Exit FromSLEEP

(Host has set Control Status

[HIBERNATE] = 1

OR

V_CELL< 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.

32

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Table 5-7. SOC_INT Pulse Condition and Width

Enable Condition

SOC_Delta ≠ 0

Always

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

1 ms

SOC1 Set

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.

SOC1 Clear Always

SysDown Set Always

When the Battery Voltage reached the SysDown Set or Clear threshold

set in the Data Flash

SysDown

Always

Clear

1 ms

State

Change

When there is a state change including charging, discharging and

relaxation. This function is disabled when SOC_Delta is set to 0.

SOC_Delta ≠ 0

Battery

Removal

INT_BREM bit is set in

OpConfig AND BIE bit is

set

1 ms

This function is disabled when BIE is cleared.

About 165ms. Same

as the OCV

command execution

time period

SOC_INT pulses for the OCV command after the initialization.

OCV

Command

After Initialization

About 165ms. Same

as the OCV

This command is to generate the SOC_INT pulse during the

initialization.

OCV

INT_FOCV bit is set in

Command

OpConfig

command execution

time period

Programmmable

SOC_INT is used to indicate the data flash update. The gauge will wait

Data Flash

Write

After Initialization AND

DFWrIndWaitTime ≠ 0

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

1 ms

Upon first assertion of Flags[OTC] or Flags[OTD] over temperature

conditions.

Always

FUNCTIONAL DESCRIPTION

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5.4 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 OVERTEMPERATURE INDICATION

5.5.1 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 CHARGING AND CHARGE-TERMINATION INDICATION

5.6.1 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].

34

FUNCTIONAL DESCRIPTION

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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

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

Byte

—

OPTCMP

—

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

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7 COMMUNICATIONS

7.1 I²C INTERFACE

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

ADDR[6:0] 0 A

Gauge generated

S

CMD[7:0]

(a) 1-byte write

A

DATA [7:0]

A

P

S

ADDR[6:0]

1

A

DATA [7:0]

(b) quick read

DATA [7:0]

N P

S

ADDR[6:0] 0 A

CMD[7:0]

A

Sr

ADDR[6:0]

1

A

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]

A . . . A P

N P

(d) incremental read

S

ADDR[6:0] 0 A

CMD[7:0]

A

DATA [7:0]

(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 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 (f_SCL) 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 read-

write standard command, a minimum of 2 seconds is required to get the result updated. For read-only

standard commands, there is no waiting time required, but the host should not issue all standard

commands more than two times per second. Otherwise, the gauge could result in a reset issue due to the

expiration of the watchdog timer.

S

ADDR [6:0] 0 A

CMD [7:0]

A

DATA [7:0]

ADDR [6:0]

A

P

66ms

Sr

1

A

DATA [7:0]

A

DATA [7:0]

N P

66ms

Waiting time inserted between two 1-byte write packets for a subcommand and reading results

(required for 100 kHz < f_SCL£ 400 kHz)

S

ADDR [6:0] 0 A

CMD [7:0]

A

DATA [7:0]

ADDR [6:0]

A

DATA [7:0]

A

P

66ms

DATA [7:0]

Sr

1

A

N P

66ms

Waiting time inserted between incremental 2-byte write packet for a subcommand and reading results

(acceptable for f_SCL£ 100 kHz)

S

ADDR [6:0] 0 A

DATA [7:0]

CMD [7:0]

DATA [7:0]

A

Sr

ADDR [6:0]

66ms

1

A

DATA [7:0]

A

DATA [7:0]

A

N P

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

Gauging Mode

Operating Condition / Comment

Duration

SLEEP

Clock stretch occurs at the beginning of all traffic as the device wakes up.

≤ 4 ms

HIBERNATE

BAT INSERT

CHECK

NORMAL

Clock stretch occurs within the packet for flow control. (after a start bit, ACK or first data bit)

Normal Ra table Data Flash updates.

≤ 4 ms

24 ms

Data Flash block writes.

72 ms

Restored Data Flash block write after loss of power.

End of discharge Ra table Data Flash update.

116 ms

144 ms

38

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8 REFERENCE SCHEMATICS

8.1 SCHEMATIC

REFERENCE SCHEMATICS

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PACKAGE OUTLINE

YZF0015

DSBGA - 0.625 mm max height

SCALE 6.500

DIE SIZE BALL GRID ARRAY

A

B

E

BALL A1

CORNER

D

C

0.625 MAX

SEATING PLANE

0.05 C

0.35

0.15

BALL TYP

1 TYP

SYMM

E

D

SYMM

2

TYP

C

B

0.5

TYP

A

1

2

3

0.35

0.25

C A B

15X

0.5 TYP

0.015

4219381/A 02/2017

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.

3. NanoFree^TMpackage configuration.

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EXAMPLE BOARD LAYOUT

YZF0015

DSBGA - 0.625 mm max height

DIE SIZE BALL GRID ARRAY

(0.5) TYP

15X ( 0.245)

(0.5) TYP

1

3

2

A

B

SYMM

C

D

E

SYMM

LAND PATTERN EXAMPLE

EXPOSED METAL SHOWN

SCALE:30X

0.05 MAX

0.05 MIN

(

0.245)

METAL

METAL UNDER

SOLDER MASK

EXPOSED

METAL

EXPOSED

METAL

(

0.245)

SOLDER MASK

OPENING

SOLDER MASK

OPENING

NON-SOLDER MASK

DEFINED

SOLDER MASK

DEFINED

(PREFERRED)

SOLDER MASK DETAILS

NOT TO SCALE

4219381/A 02/2017

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

YZF0015

DSBGA - 0.625 mm max height

DIE SIZE BALL GRID ARRAY

(0.5) TYP

(R0.05) TYP

15X ( 0.25)

1

2

3

A

B

(0.5)

TYP

METAL

TYP

SYMM

C

D

E

SYMM

SOLDER PASTE EXAMPLE

BASED ON 0.1 mm THICK STENCIL

SCALE:40X

4219381/A 02/2017

NOTES: (continued)

5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release.

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型号：	BQ27620-G1
厂家：	TEXAS INSTRUMENTS
描述：	具有动态电压相关性的系统侧电池电量监测计电池
文件：	总45页 (文件大小：796K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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