Texas Instruments BQ76905 User manual

EVM User's Guide: BQ76905EVM
BQ76905 Evaluation Module
Description
The Texas Instruments' BQ76905EVM is a complete
evaluation system for the BQ76905, The BQ76905 is
a highly integrated, high accuracy battery monitor and
protector for 2-series to 5-series Li-Ion, LiPolymer,
and LiFePO4 battery packs.
The circuit module connects directly to the cells in
a battery, or can be connected with a power supply
and the included cell simulator resistors. With the on-
board interface or compatible external interface board
and Microsoft® Windows® based PC graphical user
interface (GUI) software, the user can view the device
registers, evaluate voltage, current and temperature
accuracy, adjust protection limits and enable FET
control outputs.
Get Started
1. Order the BQ76905 EVM from ti.com.
2. Download the latest BQSTUDIO-TEST from the
BQSTUDIO tool page.
3. Follow the instructions in this user's guide to get
started.
Features
• Complete evaluation system for the BQ76905 2-
cell to 5-cell Li-Ion, LiPolymer, and LiFePO4 high
accuracy battery monitor
• Power connections available on test points
• Communication available with included USB
interface adapter or available on 4-pin connector
• Resistor cell simulator for quick setup with only a
power supply
• PC software available for configuration
Applications
•Cordless power tools and garden tools
•Vacuum cleaners
•Non-military drones
•Other industrial battery pack (2-series to 5-series)
www.ti.com Description
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 1
Copyright © 2023 Texas Instruments Incorporated

1 Evaluation Module Overview
1.1 Introduction
The BQ76905 features a high accuracy monitoring system with dedicated coulomb counter and accumulated
charge integration, a highly configurable protection subsystem, and support for host controlled cell balancing.
Integration includes low-side protection NFET drivers, a programmable LDO for external system use, and an
I2C host communication interface supporting up to 400-kHz operation with optional CRC. The evaluation module
includes one BQ76905 integrated circuit (IC), sense resistor, one thermistor, power FETs, and all other onboard
components necessary to protect the cells from overcharge, over discharge, short circuit, overcurrent discharge,
over temperature, and under temperature.
1.2 Kit Contents
• BQ76905 circuit module
• USB A to microUSB cable
1.3 Specification
This section summarizes the performance specifications of the BQ76905 circuit module in the default 5-cell
series FET configuration.
Typical voltage depends on the number of cells configured. Typical current depends on the application. Board
cooling can be required for continuous operation at or below maximum current.
Table 1-1. Performance Specification Summary
Specification Min Typ Max Unit
Input voltage BATT+ with respect to BATT– 3 – 25 V
Continuous charge or discharge current 0 – 6 A
Operating temperature range 20 25 30 °C
1.4 Device Information
Table 1-2. Device Information
EVM Part Number Chemistry Configuration Capacity
BQ76905EVM Li-Ion 5 cells Any
Note
Although capacity is shown as Any, practical limits of the physical construction of the module typically
limits the operation of the EVM to a 1P or 2P battery construction. Refer to the physical construction
section for board details.
Evaluation Module Overview www.ti.com
2BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

2 Hardware
2.1 Before You Begin
The following warnings and cautions are noted for the safety of anyone using or working close to the BQ76905
EVM. Observe all safety precautions.
Warning
The BQ76905EVM circuit module can become hot during operation due to
dissipation of heat. Avoid contact with the board. Follow all applicable safety
procedures applicable to your laboratory.
!
Caution Do not leave the EVM powered when unattended.
CAUTION
The default settings of the BQ76905 do not limit performance to the ratings of the EVM. Set all
protections appropriately and limit current for safe operation.
CAUTION
The circuit module has signal traces, components, and component leads on the bottom of the board,
which can result in exposed voltages, hot surfaces or sharp edges. Do not reach under the board
during operation.
CAUTION
The circuit module can be damaged by over temperature. To avoid damage, monitor the temperature
during evaluation and provide cooling, as needed, for your system environment. Do not operate
beyond the current and voltage limits in the Specification Table.
CAUTION
Some power supplies can be damaged by application of external voltages. If using more than
1 power supply, check your equipment requirements and use blocking diodes or other isolation
techniques, as needed, to prevent damage to your equipment.
CAUTION
The communication interface is not isolated on the EVM. Be sure no ground potential difference
exists between the computer and the EVM. Also, be aware that the computer is referenced to the
battery-potential of the EVM.
CAUTION
Connections for rated current must be made at the terminal block. Test points are not rated for the
board current.
www.ti.com Hardware
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 3
Copyright © 2023 Texas Instruments Incorporated

2.2 Required Equipment
The following equipment is required to operate the BQ76905 EVM in a simple demonstration:
• DC power supply, 0–35 V at 2.5 A
• DC voltmeter
• Computer with USB port and compatible Windows operating system and access to the internet
• Test leads to connect equipment
• Electronic load or assorted resistors
Additional equipment can be desired to operate the BQ76905 with a more extensive demonstration.
2.3 BQ76905 Circuit Module Use
The BQ76905 circuit module contains the BQ76905 IC and related circuitry to demonstrate the features of the
IC. Surface mount FETs are provided for the high current path. A thermistor provides temperature sensing on the
board. Other components provide support for the IC and connections to the board. Basic operation is described
in Section 3. For details of the circuit, refer to Section 5.
2.3.1 Cell Simulator
The EVM includes a resistive cell simulator made up of 200-Ω series resistors. The taps of the resistor network
are connected to the cell inputs using shunts on the J10 header. BAT- is always connected to the resistor divider
network. Installing a shunt on the top cell location connects the top cell input to the resistor divider to provide
simulated voltages for the other cell inputs. If the shunt is not installed on the top cell position of the header,
then all lower inputs are pulled to VSS. Installing shunts for the lower cell positions connects the input to the
simulated voltage. Since here is no indication of the cell simulator connection, the user must be aware of the
shunt installation.
2.3.2 Evaluating with Load Current
With the BQ76905 configured and the FETs enabled, discharge current can be demonstrated by attaching
appropriate resistors or a DC load at the PACK terminals as shown in Figure 2-1.
DC Power Supply
+ -
Install cell
simulator shunts
DC Load + -
Figure 2-1. Evaluating with Load Current
Hardware www.ti.com
4BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

2.3.3 Evaluating Charge and Discharge Currents
Bipolar power supplies source or sink currents to maintain the set voltage. When bipolar supplies are available,
the bipolar supplies can be used for both the battery and pack side of the board to allow charge and discharge
currents without re-connecting the equipment. Be sure to set the supplies appropriately to prevent exceeding the
ratings of the EVM.
Bipolar DC Power Supply
(source/sink)
+ -
Install cell
simulator shunts
Bipolar DC Power Supply
(source/sink) + -
Figure 2-2. Evaluating with Charge or Discharge Current
www.ti.com Hardware
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 5
Copyright © 2023 Texas Instruments Incorporated

2.3.4 Evaluating with Simulated Current
Section 3 describes connection for basic operation. Providing more than recognizable current in that
configuration can require a power supply with a significant power rating. Applying a charge current can damage
some power supplies. Figure 2-3 shows a method to force current through the control path without a high
wattage power supply or special equipment. The load power supply must be set at a low voltage in a constant
current mode. Polarity can be reversed on the load supply to simulate a charge current. The battery simulation
supply must never be reversed.
DC Power Supply
+ -
Install cell
simulator shunts DC Power Supply
(Simulated load) +
-
Figure 2-3. Simulating Current Setup
Hardware www.ti.com
6BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

2.3.5 Reducing the Cell Count
The BQ76905 must have the top and bottom cells used for proper operation. Cell count can be reduced by
shorting the unused cell inputs from the next-to-top down. Cell count can be reduced for basic evaluation by
shorting unused cells at the input terminal block. Follow the recommendations in the data sheet for which cells to
short. This works for both operation with the cell simulator and cells, but can have some side effects in transient
tests because the shorted resistors are parallel to the cell IC where the capacitor provides a signal path to
the used input. See Figure 2-4 for an example of simple reduced cell configuration for 3 cells. For the best
evaluation with reduced cells in a transient environment, short the VCx pins at the capacitor and remove the
unused input resistor. When using the cell simulator, shorting the unused cell at the terminal block is still required
to eliminate the simulated cell voltage. Shorting the cell inputs at the terminal block screw terminals is suggested
since the cell inputs are apparent if the board is re-used for a different cell count. Table 2-1 shows configuration
recommendations for reduced cell count, this table assumes the board has been set-up as detailed in Section 3.
By default, the BQ76905 EVM has VC4A/B and VC3A/B shorted at the IC inputs. However, the user
must make sure to also short CELL6 to CELL5 and CELL4 to CELL3 on the cell input terminals prior
to making any cell reduction, as explained in Section 3.
Table 2-1. Reducing Cell Count
Unused cell
(numbered from bottom
cell 1)
Short cell input
terminals
Input resistor to
remove
Replace capacitor with
0 ohm IC inputs shorted
Cell 4 CELL5 to CELL4 R8 C7 VC4A/B to VC3A/B
Cell 3 CELL3 to CELL2 R11 C9 VC3A/B to VC2
DC Power Supply
+ -
Install cell
simulator shunts
Short
CELL6 all the way
down to CELL2
Figure 2-4. Example 3 Cell Simple Evaluation Configuration
www.ti.com Hardware
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 7
Copyright © 2023 Texas Instruments Incorporated

2.3.6 Connecting Cells
The EVM is constructed with a single connection to the top and bottom of the cell stack. Cell voltage for these
cells is sensed on the board.
The cell simulator provides resistors between the cell inputs. When the cell simulator shunts are installed, these
resistors load the cells and divide the voltage to any unconnected inputs as cells are connected. If desired, then
the cell simulator shunts can be installed during cell connection and removed after cell connection. The shunts
must be removed after connection of cells or the cells are discharged by the constant drain of the cell simulator
resistors.
BAT- is the reference voltage for the IC and must be connected first. After BAT- cells can be connected in any
order. Cell connection from the bottom up minimizes the voltage step size applied to the board. Recommended
connection sequence for the EVM when connecting cells is bottom up:
1. Connect BAT–
2. Connect cells bottom up: CELL1, CELL2, CELL3 ...
3. Be sure the cell simulator shunts are removed
Figure 2-5 shows an example connecting cells with an EVM configuration reduced to 4 cells.
Remove cell
simulator shunts to
avoid draining cells
If connecting cells confirm operation before connecting.
Use all appropriate fusing, insulation, isolation and
shielding necessary for safe operation. Board has exposed
contacts. Do not leave unattended
For 4 cells, connect 3th
cell to CELL6 to CELL3
inputs
Figure 2-5. Example Connection with 4 Cells
Hardware www.ti.com
8BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

2.3.7 Connecting to a Host
After initial operation of the monitor with the BQStudio software, consider operating the board connected to and
controlled by a microcontroller board. To do this, unpopulate J6 and J2, and populate J1 and J5. J6 and J2
disconnect the I2C lines of the BQ76905 from the on-board MCU. J1 and J5 connect the I2C pullup resistors to
REGOUT.
DC Power Supply
+ -
Install cell
simulator shunts
Add shunts for
pull-ups if pull-
ups not provided
on MCU board
MCU
Evaluation Board
SCL
Remove shunts
for on-board MCU
connection
SDA
Figure 2-6. Host Connection Concept
2.3.8 Hardware Configuration
2.3.8.1 Configuration Jumpers
Certain features on the BQ76905EVM can be configured by jumpers or shunts on headers. See Section 5.1 for
details of the header pins.
J1 and J5 connect the BQ76905 I2C lines to pull-up resistors at REGOUT for off-board MCU communications.
J2 and J6 connect the I2C lines of the BQ76905 to the on-board MCU.
J7 connects the ALERT pin to a pull-up resistor at REGOUT.
J8 connects/disconnects the on-board thermistor from the TS pin.
J10 cell simulator connections.
The cell simulator headers and are discussed in board connection diagrams.
2.3.9 Configuration Register Programming
Configuration register programming is done once hardware configuration is set with jumpers. Configuration
registers are set in the Data Memory screen and are different from the status registers displayed in the Registers
screen. See the BQ76905 data sheet (SLUSF45) and supporting documentation for register information. When
a configuration file is available, the file can be imported to set all operational selections at once. However, a
configuration file loaded with Data Memory Import can load as little as 1 parameter, so the user must be familiar
with the contents of imported files. With a new device or after loading a configuration file, individual register
changes can be made. Configuration register programming typically involves the following general principles
selected in various register names:
1. Selection of the protection features to be enabled
2. Selection of the protection thresholds for the enabled features
3. Setting the FET control options
4. Exporting (saving) the configuration register file for future use
www.ti.com Hardware
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 9
Copyright © 2023 Texas Instruments Incorporated

3 Quick Start Guide
The BQ76905 registers must be configured to enable most protections, select the monitored cells, and enable
the protection FETs on the EVM. This section does not describe current protection settings.
These steps describe quick connection of the BQ76905 EVM to demonstrate operation of the AFE portion of the
EVM. For more detailed descriptions, refer to other sections of the user's guide.
Refer to Figure 3-1 for the following steps.
1. Download the BQSTUDIO software from the tool folder link www.ti.com/tool/BQSTUDIO or search from
www.ti.com.
2. Install the BQStudio software (see Section 4.1.2).
3. Install the cell simulator shunts.
4. VC4A to VC4B and VC3A to VC3B are shorted directly at the pins. However, CELL6 to CELL 5 and CELL4
to CELL 3 must also be shorted at the cell-side for proper circuit module functionality.
5. Position shunts for the I2C to MCU connection.
6. Attach the on-board communication adapter USB connector to the PC using USB cable.
7. Connect a 0-V DC power supply capable of 250 mA minimum between the “BAT-” and "7P" terminals and
adjust to approximately 15 V.
8. Start the BQStudio software. If there is proper communication, then the GUI opens with a register display.
Click on the Scan button to enable repeated update of the display. The power supply can be adjusted within
range of the part to observe voltage changes in the GUI register display.
9. Select the Data Memory button in the BQStudio window.
10. Select the Settings button. Set the Enabled Protections A CUV bit.
11. Select the Protections button. Set the Cell Undervoltage Protection Threshold to 2800.
12. In the Commands panel click on the FET_ENABLE button.
13. In the Registers view click on the Scan icon so that the registers update periodically. Observe that the CHG
and DSG bits in the Battery Status register are on. Measure the PACK voltage on the board if desired.
14. Adjust the supply voltage to approximately 12.5 V. In the registers view observe that the DSG bit goes off.
15. Make other adjustments as desired for evaluation. See other sections of this user guide for details of
operation.
16. When complete with this quick start demonstration, exit the BQStudio software and turn off the power supply.
Refer to other sections of this user's guide for additional details.
Short
CELL6 to CELL5 and
CELL4 to CELL3
DC Power Supply
+ -
Install cell
simulator shunts
Position shunts
to uC_SCL and
uC_SDA
Figure 3-1. EVM Connection for Basic Operation
Quick Start Guide www.ti.com
10 BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

4 Software
4.1 Battery Management Studio Software
The Battery Management Studio software is used for evaluation of the BQ76905 monitor. This software is also
identified as BQStudio for a compact name. If an earlier version of the BQStudio software is already installed
from another product evaluation, then install BQStudio software again to load the configuration files and tools
specific to the current version of the BQ76905.
4.1.1 System Requirements
The BQStudio software requires a Windows 7, or later, operating system. Additional items are required and are
described in the installation windows.
4.1.2 Installing BQStudio
Find the latest software version in the software section of the product folder http://www.ti.com/tool/BQSTUDIO
or search from ti.com. There are multiple versions available, but the BQSTUDIO-TEST version needs to be the
version used with the BQ76905 EVM. Check periodically for software updates. Use the following steps to install
the BQStudio software:
1. Uninstall older versions of BQStudio software. After uninstalling, delete the BatteryManagementStudio
program directory.
2. Copy the archive file to a directory of your choice, extract all files and run the Battery Management Studio-
xxxxxx-Setup.exe application.
3. Follow the instructions and make selections as required on the setup windows selecting Next, as required.
TI recommends installing the software in the default location.
4. On the last window select option check-boxes desired and Finish to complete the BQStudio software
installation.
4.1.3 BQ76905 bqz File Installation
The BQStudio software uses a .bqz file to configure the displays for the BQ76905 device family or specific family
device. This is normally provided in the BQStudio installation. If provided separately, copy the .bqz file to the
config directory in the installation, typically C:\ti\BatteryManagementStudio\config.
4.1.4 BQStudio Operation and Registers View
BQStudio is used to communicate to the BQ76905 for evaluation. BQStudio includes several tools to aid in
configuration, calibration and data display of the BQ76905 during evaluation.
Although the software runs without connection to an interface board or powered device, TI recommends to have
the interface connected and the device on when starting the software. Follow the directions in Section 3. Figure
3-1 shows typical connections for operation with the BQStudio software.
Start the software from the desktop shortcut Battery Management Studio or from the Start menu.
When started, the software looks for the communication interface and the device. If the device is not found, then
the device opens a Target Selection Wizard. On the first window select the Monitor or All class and click the Next
button. On the second window select the newest or appropriate BQ76905 version in the list and click the Finish
button. This selection is remembered until the software is re-started. If the device is not found, then the user is
presented with a Proceed? window, which must be acknowledged. If the software still cannot find the device,
then a Battery Management Studio pop-up window appears indicating communication status. Acknowledge the
message to proceed.
www.ti.com Software
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 11
Copyright © 2023 Texas Instruments Incorporated

Figure 4-1. Target Selection Wizard
If the software was started without a communication interface adapter, then a Battery Management Studio
pop-up window indicates a free adapter is not available. Acknowledge the message to proceed. Errors appear
in the left bottom border of the Battery Management Studio screen. Correct the problem with the adapter and
restart the software.
BQStudio contains a user's guide for general operation of the software. Refer to the menu selection Help | Help
Contents for information.
The BQStudio window appears as shown in Figure 4-2. The register area is blank since the device is not
attached.
The center panel of BQStudio displays tool tips when the cursor is held over an item name. The tool tip provides
some description of the item. The tool tip closes after approximately 30 seconds. To avoid the tool tip display
move the cursor to the value or units column, or to the Dashboard panel.
Software www.ti.com
12 BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

Figure 4-2. BQStudio Window without Device
Without a device, BQStudio operates with reduced functions. Tools can be browsed and data fields inspected,
but data cannot be entered.
The dashboard on the left-side of the window shows the adapter, device and simple voltage and current
displays. The dashboard updates periodically unless Auto Refresh is stopped by clicking on the banner. The
right side of the window has the Commands panel.
The center panel of the window initially shows the Registers tab. The register display shows device status
registers and is read once when the device is detected. To update the register values select the Refresh button
at the top of the Registers tab. To repeatedly read the registers select the Scan button. To repeatedly read and
log the register values to a file select the Start Log button and follow the prompts to save a log file. When a log
is running, select Stop Log to end the log and close the file. The Parameter View selection allows the choice of
basic parameters which shows commonly used registers, or all parameters which shows more registers.
If a device is connected and powered after BQStudio is powered, then the dashboard auto-detects the device
and update the device and register display. Figure 4-3 shows a register display with a connected device.
www.ti.com Software
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 13
Copyright © 2023 Texas Instruments Incorporated

Figure 4-3. Register View with Device
The available tools for the device are shown at the top of the window and can be selected by clicking on the tool
icon. Tools can also be selected from the View menu as shown in Figure 4-4. Opening a new tool can change
the center tab of the window. Not all devices have all the tools described. Multiple tools can be active at one
time, which use the center pane for display are shown as a tabs at the top of the center section. These tabs can
be closed with the X as desired, but closing the tab can terminate the operation running in the tab.
Figure 4-4. Tool Selections
Software www.ti.com
14 BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

4.1.5 Commands
The Commands tab is displayed on the right side of the BQStudio window. Buttons in this tab allow reading
various information about the device and certain operations by sending a command to the device. Commands
and returned data are shown in the Log Panel of the tab. The seal function is unusual in general evaluation and
is not recommended during initial evaluation.
CAUTION
Sealing the device without remembering the key reduces the function of the EVM.
4.1.6 Data Memory
The data memory tool is used to configure the device. Configuration files can be saved and loaded later to
resume evaluation. At power up, the device is loaded with factory configurations. Configuration can be entered
in the volatile registers using the Data Memory tool. The Data Memory tool displays as a tab in the center pane
of the BQStudio window. Figure 4-5 shows the initial data memory view with a device connected. Configuration
settings are grouped into different functions accessed with buttons on the left side of the panel. Other functional
sections can be displayed by clicking on the named button.
Figure 4-5. Data Memory View
4.1.6.1 Entering, Saving, and Loading Configuration
Most of the configuration of the BQ76905 is accomplished through setting values in the data memory. The data
memory locations are accessed using the buttons in the Data Memory view. The Parameter View selection at
the top of the panel allows the choice of basic parameters, which shows commonly used parameters, or all
parameters which shows more configuration parameters. Data values can be changed by selecting and entering
a value. Parameter registers, which are bit fields, can be changed by selecting the bit in the pop up when the
register or the value is selected. Data Memory must be written after bit changes, and a button is provided under
the bit field. Figure 4-6 shows the bit field for the Enabled Protections A, which is one of the most basic settings
that must typically be changed with the EVM.
www.ti.com Software
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 15
Copyright © 2023 Texas Instruments Incorporated

Figure 4-6. Data Memory Bit Field Change
Changes to configuration by memory changes take place immediately, however the FETs are enabled using the
FET_ENABLE command. Enabling a protection and enabling the protection action on a FET are not sufficient,
the FETs must be enabled with the command.
The Export tool in the Data Memory view allows saving the configuration data to a comma-separated-value file
format, which can be accessed by a spreadsheet program. Reading data before export with the Read All button
loads the data from the part rather than values which can be only in the view. The Import tool allows loading
such a saved file into the view so that the file can be written to the device. The Write All tool writes all values in
the view into registers in the device.
4.1.7 Command Sequences
Features are controlled by commands as described in the BQ76905 data sheet. Data is available from registers,
and the registers view shows data, but a user can send specific commands to the device. The Command
sequences tool allows this operation and is shown in Figure 4-7. The Device Send and Receive section allows
read or write to a single or consecutive locations. The Command Sequence section allows reads and writes to
be intermixed in a sequence. Sequences can be stored to files or called from files. Files can be assigned to
buttons in the Command Sequence File Assignment Buttons section. Results can be viewed in the Transaction
Log and saved to a file if desired.
Figure 4-7. Command Sequence View
Software www.ti.com
16 BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

5 Hardware Design Files
5.1 Schematic
Figure 5-1 through Figure 5-2 illustrate the schematics.
2P
1P
BAT-
4P
3P
BAT
VSS
VSS
VSS
VSS
GND
SRP SRN
5P
100
R17
100
R18
100pF
C15
0.1uF
C19
TP20
0.001
R21
t°
RT1
VC3
VC2
VC1
NT1
Net-Tie
40V
D2
100
R2
1P
3P
4P
TP24
BAT-
VC0
VC5
BAT-
1P
2P
3P
4P
VSS
GND
GND
TP21
100pF
C3
VSS
1uF
C4
VSS
TP9
Input
25V 6A
5P
5P
WAKE
VC4
220nF
C7
0
C8
220nF
C9
220nF
C10
220nF
C12
220nF
C13
TP13
TP14
TP16
TP17
TP18
TP19
TP28 TP29
VC0
VC1
VC2
VC3
VC4
VC5
VC6
VC7
REGSRC
REGOUT
VSS
TS
6P
7P
6P
7P
6P
7P
0
C6
220nF
C5
VC6
VC7
TP3 External I2C
Connection
4
1
2
3
J4
GND
SDA
SCL
E2E1
12
U3
12
U2
REGOUT
10k
R4
TP4
uC_SDA
uC_SCL 1
2
J2
1
2
J6
1
2
J5
1
2
J1
TP8
REGOUT
10k
R3
On-board (EV2400)
MCU connections
Pull-ups to
REGOUT
25V 6A Max
TP25
PACK-
PACK+
PACK-
PACK-
PACK+
E3
0.1uF
C18
0.1uF
C14
Output
4
7,8 1,2,3
5,6,
Q2
4
7,8
1,2,3
5,6,
Q1
0.1uF
C21
0.1uF
C20
10M
R19
10M
R20
DSG
CHG
1uF
C1
REGSRC
41
32
S1
1P
REGOUT
10k
R5
TP11
1
2
J7
CHGDSG
2P
10.0
R6
10.0
R7
10.0
R8
10.0
R9
10.0
R11
10.0
R12
10.0
R13
10.0
R14
TP26
VSS
TP27
VSS
0.1uF
C17
0.1uF
C16
VSS VSS
TP12
TP10
1
2
J8
BAT-
40V
D1
16V
D6
0
R1
TP1
TP5 TP6
TP2
TP7
TP22 TP23
5
4
1
2
3
6
7
8
J3
GNDGND
TP15
VSS
Thermistor and Wake
button for TS pin
TS
D5
VSS
VSS
470pF
50V
C11
1.8V
D4
VSS
1µF
50V
C2
TP33 TP34
5.1k
R15
5.1k
R16
100
R42
100
R41
REGOUT
7P
BAT+
BAT+
3
2
1
Q3
D3
1.0k
R10
1
2
3
4
J9
VC0
5
SRP
6
SRN
7
TS
8
DSG 9
CHG 10
VSS 11
SCL 12
SDA 13
ALERT 14
REGOUT 15
REGSRC 16
BAT
17
EP 21
VC3A
1
VC3B
2
VC2
3
VC1
4
VC5
18
VC4A
19
VC4B
20
BQ76905RGR
U1
Figure 5-1. Schematic Diagram Monitor
www.ti.com Hardware Design Files
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 17
Copyright © 2023 Texas Instruments Incorporated

TPS 76 333 DBVR
IN
1
2
EN
3NC 4
OUT 5
GND
U7
VBUS 1
D- 2
D+ 3
ID 4
GND 5
67 8
11 10
9
J11
VBUS TP30
33R31
33R32
10k
R34
1
MP 2MP 1
2
MP 3 MP4
S2
10k
R40
2200pF
C32
3.3V
3.3V
0.1uF
C24
QGND
10µF
C25
10µF
C26
0.1uF
C27
VBUS 3.3V
0.1uF
C28
0.1uF
C22
0.1uF
C30
2.0k
R33
1.0M
R36
1.0M
R35
VUS B
VUS B
0.47uF
C29
0.47uF
C23
4
1
2
3
J13
TP31
1
2
3
Y1
VBUS
0.47uF
C31
330
R37
330
R38
330
R39
TP32 GND
1
2
J12
QGND
QGNDQGND QGND
QGND
QGND
NT4
Ne t-Tie
QGND
12
U9
12
U8
MSP 4 30F5529IPN
P6.4/CB4/A4 1
P6.5/CB5/A5 2
P6.6/CB6/A6 3
P6.7/CB7/A7 4
P7.0/CB8/A12
5
P7.1/CB9/A13
6
P7.2/CB10/A14
7
P7.3/CB11/A15
8
P5.0/A8/VR EF +/VERE F+
9
P5.1/A9/VR EF -/VEREF-
10
AVCC1
11
P5.4/XIN
12
P5.5/XOUT
13
AVSS1 14
P8.0 15
P8.1 16
P8.2 17
DVCC1
18 DVSS 1 19
VC ORE
20
P1.0/TA0CLK/ACLK
21
P1.1/TA0.0
22
P1.2/TA0.1
23
P1.3/TA0.2
24
P1.4/TA0.3
25
P1.5/TA0.4
26
P1.6/TA1CLK/CBOUT
27
P1.7/TA1.0
28
P2.0/TA1.1 29
P2.1/TA1.2 30
P2.2/TA2CLK/SMCLK 31
P2.3/TA2.0 32
P2.4/TA2.1 33
P2.5/TA2.2 34
P2.6/RTCCLK/DMAE0 35
P2.7/UCB0STE/UCA0CLK 36
P3.0/UCB0SIMO/UCB0S DA
37
P 3.1 /UCB0 S OMI/UCB0 S CL
38
P3.2/UCB0CLK/UCA0STE
39
P3.3/UCA0TXD/UCA0SIMO
40
P 3.4 /UCA0RXD/UCA0S OMI
41
P3.5/TB0.5
42
P3.6/TB0.6
43
P3.7/TB0O UTH/SVMO UT
44
P4.0/P M_UCB1S TE/PM_UCA1CLK 45
P4.1/P M_UCB1S IMO /P M_UCB1S DA 46
P 4.2 /P M_UCB1 S OMI/P M_UCB1S C L 47
P4.3/P M_UCB1CLK/P M_UCA1STE 48
DVS S 2 49 DVCC2
50
P4.4/P M_UCA1TXD/PM_UCA1 SIMO 51
P 4.5 /P M_UCA1RXD/PM_UCA1S OMI 52
P4.6/P M_NONE 53
P4.7/P M_NONE 54
P5.6/TB0.0
55
P5.7/TB0.1
56
P7.4/TB0.2
57
P7.5/TB0.3
58
P7.6/TB0.4
59
P7.7/TB0CLK/MCLK
60
VS S U 6 1
PU.0/DP 62
PUR 63
PU.1/DM 64
VBUS
65
VUS B
66
V1 8
67
AVSS2 68
P5.2/XT2IN
69
P5.3/XT2O UT
70
TES T/S BWTCK 71
P J .0/ TDO 72
P J .1/ TDI/TCLK 73
P J .2/ TMS 7 4
P J .3/ TCK 75
RS T/NMI/SBWTDIO 76
P6.0/CB0/A0 77
P6.1/CB1/A1 78
P6.2/CB2/A2 79
P6.3/CB3/A3 80
U4
NT2
Ne t-Tie
NT3
Ne t-Tie
S MBC1
S MBD1
12
U5
12
U6
LED1
LED2
LED3
LED1
LED2
LED3
RST
TES T
DP
DM
PUR
RST
TES T
DM
DP
PUR
Gre en
D7
Gre en
D8
Gre en
D9
3.3V
10k
R28
10k
R29
uC_S CL
uC_S DA
200
R24
200
R25
200
R26
200
R27
200
R30
5P
4P
3P
2P
1P
BAT-
1 2
3 4
5 6
7 8
9 10
11 12
13 14
J10
6P
7P
200
R23
200
R22
Ce ll Simulator - P opulate
shunts to us e cell s imulator if
not conne cting ba tte ry ce lls .
VSS
Figure 5-2. Schematic Diagram Adapter
Hardware Design Files www.ti.com
18 BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

5.2 Board Layout
The BQ76905EVM circuit module is a 2.175-inch × 4.4-inch 2-layer circuit card assembly. The BQ76905EVM is
designed for easy assembly with cell connections on the left edge to a terminal block. Pack terminals are on the
bottom edge using a terminal block. Wide trace areas are used reducing voltage drops on the high current paths.
An on-board interface adapter with USB connector is located in the right lower corner.
See additional information in the configuration and operation sections of this document.
Figure 5-3. Top Layer
Figure 5-4. Bottom Layer
www.ti.com Hardware Design Files
SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
BQ76905 Evaluation Module 19
Copyright © 2023 Texas Instruments Incorporated

5.3 Bill of Materials
The bill of materials for the circuit module is shown in Table 5-1. Substitute parts can be used in the manufacturing of the assembly.
Table 5-1. Bill of Materials
Designator Quantity Value Description Package
Reference
Part Number Manufacturer
!PCB1 1 Printed Circuit Board BMS057 Any
C1 1 1uF CAP, CERM, 1 uF, 16 V, +/- 10%, X7R, 0805 0805 EMK212B7105KG-T Taiyo Yuden
C2 1 1uF CAP, CERM, 1 uF, 50 V, +/- 10%, X7R, 0805 0805 885012207103 Wurth Elektronik
C3, C15 2 100 pF CAP, CERM, 100 pF, 50 V, +/- 5%, C0G/NP0,
0603
0603 C0603C101J5GACTU Kemet
C4 1 1uF CAP, CERM, 1 uF, 50 V, +/- 10%, X7R, AEC-
Q200 Grade 1, 1206
1206 CGA5L3X7R1H105K160AB TDK
C5, C7, C9, C10,
C12, C13
6 0.22uF CAP, CERM, 0.22 uF, 50 V, +/- 10%, X7R, 0603 0603 C1608X7R1H224K080AB TDK
C6, C8 2 0 RES, 0, 1%, 0.1 W, AEC-Q200 Grade 0, 0603 0603 RMCF0603ZT0R00 Stackpole Electronics Inc
C11 1 470 pF CAP, CERM, 470 pF, 50 V, +/- 10%, X7R, 0603 0603 C0603C471K5RACTU Kemet
C14, C18, C19, C20,
C21
5 0.1uF CAP, CERM, 0.1 uF, 50 V, +/- 10%, X7R, 0603 0603 885012206095 Wurth Elektronik
C22, C24, C27, C28,
C30
5 0.1uF CAP, CERM, 0.1 uF, 16 V, +/- 10%, X7R, 0402 0402 885012205037 Wurth Elektronik
C23, C29, C31 3 0.47uF CAP, CERM, 0.47 uF, 6.3 V, +/- 10%, X5R, 0402 0402 04026D474KAT2A AVX
C25, C26 2 10uF CAP, CERM, 10 µF, 16 V,+/- 10%, X5R, 0805 0805 CL21A106KOQNNNG Samsung Electro-
Mechanics
C32 1 2200 pF CAP, CERM, 2200 pF, 10 V, +/- 10%, X7R, 0402 0402 885012205008 Wurth Elektronik
D1, D2, D3 3 40 V Diode, Schottky, 40 V, 0.2 A, SOT-323 SOT-323 BAS40W-7-F Diodes Inc.
D4 1 1.8V Diode, Zener, 1.8 V, 500 mW, SOD-123 SOD-123
D6 1 16 V Diode, Zener, 16 V, 500 mW, SOD-123 SOD-123 MMSZ5246B-7-F Diodes Inc.
D7, D8, D9 3 Green LED, Green, SMD LED_0603 150060VS75000 Wurth Elektronik
H1, H2, H3, H4 4 Bumpon, Hemisphere, 0.44 X 0.20, Clear Transparent
Bumpon
SJ-5303 (CLEAR) 3M
J1, J2, J5, J6, J7, J8 6 Header, 100mil, 2x1, Tin, TH Header, 2 PIN,
100mil, Tin
PEC02SAAN Sullins Connector
Solutions
Hardware Design Files www.ti.com
20 BQ76905 Evaluation Module SLUUCY9 – NOVEMBER 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated