Texas Instruments bq26220EVM-001 User manual

User’s Guide
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User’s Guide

2
EVM IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION
PURPOSES ONLY and is not considered by TI to be fit for commercial use. As such, the goods being provided
may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective
considerations, including product safety measures typically found in the end product incorporating the goods.
As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic
compatibility and therefore may not meet the technical requirements of the directive.
Should this evaluation kit not meet the specifications indicated in the EVM User’s Guide, the kit may be returned
within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE
WARRANTY MADE BY SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED,
IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user
indemnifies TI from all claims arising from the handling or use of the goods. Please be aware that the products
received may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). Due to the open construction
of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic
discharge.
EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE
TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not
exclusive.
TI assumes no liability for applications assistance, customer product design, software performance, or
infringement of patents or services described herein.
Please read the EVM User’s Guide and, specifically, the EVM Warnings and Restrictions notice in the EVM
User’s Guide prior to handling the product. This notice contains important safety information about temperatures
and voltages. For further safety concerns, please contact the TI application engineer.
Persons handling the product must have electronics training and observe good laboratory practice standards.
No license is granted under any patent right or other intellectual property right of TI covering or relating to any
machine, process, or combination in which such TI products or services might be or are used.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated

3
DYNAMIC WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the input voltage range of 2.6 V to 4.5 V and the output range of 2.6 V
to 4.5 V.
Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM.
If there are questions concerning the input range, please contact a TI field representative prior to connecting
the input power.
Applying loads outside of the specified output range may result in unintended operation and/or possible
permanent damage to the EVM. Please consult the EVM User’s Guide prior to connecting any load to the EVM
output. If there is uncertainty as to the load specification, please contact a TI field representative.
During normal operation, some circuit components may have case temperatures greater than 70°C. The EVM
is designed to operate properly with certain components above 70°C as long as the input and output ranges are
maintained. These components include but are not limited to linear regulators, switching transistors, pass
transistors, and current sense resistors. These types of devices can be identified using the EVM schematic
located in the EVM User’s Guide. When placing measurement probes near these devices during operation,
please be aware that these devices may be very warm to the touch.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated

SLUU151 –April 2003
4bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
bq26220EVM-001 Single Cell Battery Monitor Evaluation
Module
Portable Powe
r
Contents
1 bq26220EVM–001 Battery Monitor Evaluation Module 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Circuit Module 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 EVM Hardware and Software Setup 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Operation 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Introduction
The bq26220EVM-001 is a complete evaluation system for the bq26220 flash-based battery
monitoring IC. The EVM includes one bq26220 circuit module, an EV2200 PC interface board
for gas-gauge evaluation, a PC serial cable, and Windows-based PC software.The circuit
module includes one bq26220 and all other components on-board necessary to monitor capacity
and other critical parameters in a one-cell Li-Ion battery pack.The circuit module connects
directly across the cell in a battery. With the EV2200 interface board and software, the user can
read the bq26220 data registers and evaluate the functions of the bq26220 under different
charge and discharge conditions
1.1 Features
The following list highlights some of the features of the bq26220 single cell battery monitor.
•Complete evaluation system for the bq26220 battery monitor IC
•Populated circuit module for quick setup
•PC software and interface board for easy evaluation
•Software allows data logging for system analysis
1.2 Kit Contents
•bq26220 circuit module with sense resistor
•EV2200 PC interface board
•Set of evaluation software disks entitled EV2200–26220
•PC serial cable
•Set of support documentation
1.3 Ordering Information
Table 1. Ordering Information
EVM Part Number Additional Devices Chemistry Pack Voltage Capacity
bq26220EVM–001 None Li-Ion/NiMH/NiCd 2.6 V to 4.5 V Any

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bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
2 Circuit Module
The circuit module in the bq26220EVM-001 is a complete and compact example solution for battery
monitoring of a single-cell Li-on pack.The circuit module incorporates a bq26220 battery monitor IC and all
other components necessary to accurately protect and monitor the charge and discharge of one Li-Ion
cell. This EVM can also be used for 3-series NiMH applications.
Contacts on the circuit module provide direct connection to the cell (BAT+, BAT–) and the serial
communications port (HDQ).The system load and charger connect across PACK+ and PACK–.
2.1 Pin Descriptions
•BAT+/PACK+ Cell positive/pack positive
•BAT–Cell negative
•PACK–Pack negative
•HDQ Serial communications port
•STAT Status output
•GPIO Programmable input/output port
2.2 Circuit Module Schematic
The schematic shows the circuit for the bq26220EVM-001 implementation.
2.2.1 Schematic
Figure 1 is the bq26220EVM-001 (SLUP165) circuit module schematic diagram.
1
2
3
4
8
7
6
GPIO
SRP
SRN
BAT
RBI
VCC
VSS
HDQ
U1
bq26220PW
J2
D2
5.6 V
D1
5.6 V
1
J1
HDQ
1
2
5
3
1
2
PACK+
GPIO
PACK–
BAT–
R7 100 kΩ
UDG–03024
R6 20 mΩ
R5 100 kΩ
R3 100 Ω
R1
100 ΩR2
100 Ω
C2
0.1 µF
C3
0.1 µFC2
0.1 µF
R4
100 Ω
NOTE: R1, R2, and D1 are required for external use only.
Figure 1. bq26220EVM–001 Schematic

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6bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
2.3 Circuit Module Physical Layouts
This section contains the board layout and assembly drawings for the bq26220EVM-001 circuit module (SLUP165)
2.3.1 Board Layout
Figure 2 shows the PCB layers and assembly drawing for the circuit module.
Figure 2. Top Assembly
Figure 3. Silk 1

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bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
Figure 4. Layer 1
Figure 5. Layer 2

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8bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
2.4 List of Materials
Table 2. List of Materials
Ref Des Qty-001 Description MFG MFG Part# Size
PCB 1 Printed-circuit board, 0.031, FR4, SMOBC, HASL Any See FAB DWG
Terminal 1 Terminal block 3.5 mm On Shore ED555/2DS 3.5 mm ×2
Terminal 1 Terminal block 3.5 mm On Shore ED555/2DS 3.5 mm ×3
C1, C2, C3 3Capacitor, ceramic, 0.1 µF, 16 V, ±10%, X7R Panasonic ECJ-1VB1C104K 603
R6 1 Resistor, 0.020 Ω, 1/2 W, 1% IRC LR2010-01-R020-F 2010
R5, R7 2Resistor, 100 kΩ, 1/16 W, 5% Panasonic ERJ-3GSYJ104 603
R1, R2, R3, R4 4Resistor, 100 Ω, 1/16 W, 5% Venkel ERJ-3GSYJ101 603
D1, D2 2Diode, zener, 5.6 V Zetex BZX84C5V6 SPT-23
U1 1 Integrated circuit, gas gauge, bq26220PW TI bq26220PW TSSOP-8
Component count 16
Assembly Notes:
1. This assembly is ESD sensitive.
2. This assembly must comply with IPC–A–610 class 2 or better.
3. This assembly must be clean of flux residues and contaminants.
4. Use of no-clean flux is not acceptable.
2.5 Performance Specification Summary
This section summarizes the performance specifications of the bq26220EVM-001 circuit module. Table 3 gives the
performance specifications of the circuit.
Table 3. Performance Specification Summary(1)
Specification MIN TYP MAX UNIT
Input voltage BAT+/BAT–2.6 4.5 V
Charge and discharge current 4 A
Note: Maximum charge and discharge current. is limited by the PCB design and power dissipation of the 20-mΩ, 1/2 W sense resistor included
on the PCB.

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bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
3 EVM Hardware and Software Setup
This section describes how to install the EV2200-26220 PC software and how to connect the components
of the EVM.
3.1 Software Installation
The following steps install the EV2200-26220 software:
1. Insert disk 1 into a 3 1/2 inch floppy drive.
2. Select the 3 1/2 inch drive using My Computer.
3. Double-click on the Setup.exe icon.
4. The setup program prompts for the remaining disks and installs a Windows application group.
3.2 Hardware Installation
There are three hardware components to the bq26220EVM-001:
1. The bq26220EVM-001 circuit module
2. The EV2200 PC interface board
3. The PC
3.2.1 Connecting the bq26220EVM-001 Circuit Module to a Battery Pack
Figure 6 shows how to connect the bq26220EVM-001 circuit module to a Li-Ion cell and the system load/charger.
Cell
Load
bq26220EVM-001
Circuit Module
Charger
PACK
BAT–
PACK–
BAT
PACK
PACK–
Battery Pack
Figure 6. bq26220EVM-001 Circuit Module Connection to Cells and System Load/Charger

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10 bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
3.2.2 PC Interface Connection
The following steps configure the hardware for interface to the PC:
1. Connect bq26220EVM–001 to the EV2200 using wire leads as in the following table.
Table 4. Circuit Module-to-EV2200 Connection
bq26220 Based Battery EV2200
HDQ SMBD/HDQ1
PACK–VSS
2. Connect the PC serial cable to the EV2200 and the PC COM port.
The bq26220EVM-001 is now set up for operation.

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bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
4 Operation
This section details the operation of the bq26220EVM-001 software.
4.1 Starting the Program
Run EV2200–26220 from the Start|Programs|Texas Instruments|bq26220 Battery Monitor menu
sequence.The software defaults to PC Com port 1 for communication.If the EV2200 is connected to Com
port 1, the program should load and display the initial data screen.
Figure 7. Internal Register Screen
If the EV2200 is connected to PC Com port 2 or no port, the program displays a blank screen in Binary,
Hex, Dec, and Total Decimal columns.
Once the appropriate Com Port is selected, the program loads the initial register screen.The com port can
be changed by selecting the port under the Options menu.

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12 bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
4.2 Initialization
This section describes the settings required before the bq26220 is evaluated.
4.2.1 Setting Programmable bq26220 Options
4.2.1.1 Wake-Up Threshold
Select the wake-up threshold with the woe pulldown tab at location 0x64.This designates the potential
across the sense resistor, below which the bq26220 goes to sleep.
4.2.1.2 GPIO and STAT Boxes
To configure the GPIO pin as input or output click on the GPIO box at 0x64 location. To turn off the GPIO
as ouput, set the GPIO pin by clicking the STAT box at the 0x64 location. To reset, click the box again.
4.2.2 Register Clearing
Each counter in the bq26220 can be cleared (set to 00) by depressing the adjacent Clr button.The All
button clears all counting registers in one sequence.

SLUU151 –April 2003
13
bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
4.3 Reading and Writing Flash Memory
The flash memory on the bq26220 can store battery-pack specific parameters that can be used by the
host system in its capacity monitoring algorithm.To read the flash memory, click on the Flash button to
select the flash data screen. Click the Read Flash button to read all flash pages or click on the individual
page number to read the pages individually.
Each flash location can be modified by clicking on the individual location and entering the new value in
hex.
The flash values can be stored to disk as one data file.To do this, select File|Save Flash File and enter
the file name in the Store Flash File window.The file can subsequently be opened using the the
File|Open Flash File command from the pull down menu.Once the flash file is loaded into the program,
the Write Flash button can be used to store the data in the bq26220.
Figure 8. Flash Register Screen

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14 bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
4.4 RAM Addressing
The RAM page of memory can be viewed by selecting the RAM data screen.
Click on the Read RAM button to read the RAM locations.
Each RAM location can be modified by clicking on the individual location and entering the new value in
hex.The RAM values can be stored to disk as one data file.To do this, select File|Save RAM File and
enter the file name in the Store Ram File window.The file can subsequently be opened using the the
File|Open Ram File command from the pulldown menu. Once the FLASH file is loaded into the program
the Write RAM button can be used to store the data in the bq26220.
On this screen, two other buttons are available to transfer data RAM to flash page 0 and from flash page 0
to RAM.
Figure 9. RAM Register Screen

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bq26220EVM-001 Single Cell Battery Monitor Evaluation Module
4.5 Data Logging
The bq26220 registers can be logged by using the data log function.To log the data and create a log file
1. Select Options|Logging Options to select the registers to log and set the logging interval.
2. File|Start Data Log from the pulldown menu.
3. Enter the name of the data log file in the Name Datalog File box
4. Click on the Open button
5. To stop the data logging, select File|Close Data Log from the pulldown menu
The file can be imported into a text editor, spreadsheet, or word processor program.
Example data log:
EV2200–26220 Version: 0.0.1 Texas Instruments bq26220 battery monitor
5/6/02 3:04:23 PM
ROM ID: 32 8C 00 02 01 11 00 26
Sample Stamp Elapsed(s) DCR CCR SCR DTC CTC MODE/WOE CLR TEMP
1 3:04:33 PM 10 27 3 0 2008 955 78 96 297
2 3:04:43 PM 20 27 3 0 2008 955 78 96 297
3 3:04:53 PM 30 27 3 0 2008 955 78 96 297
4 3:05:03 PM 40 27 3 0 2008 955 78 96 297
5 3:05:13 PM 50 27 3 0 2053 955 78 96 297
6 3:05:23 PM 60 27 3 0 2063 955 78 96 297
7 3:05:33 PM 70 27 3 0 2074 955 78 96 297
8 3:05:43 PM 80 27 3 0 2086 955 78 96 297
9 3:05:53 PM 90 27 3 0 2098 955 78 96 297
10 3:06:03 PM 100 27 3 0 21–7 955 78 96 297
11 3:06:13 PM 110 27 3 0 2123 955 78 96 297
12 3:06:23 PM 120 27 3 0 2134 955 78 96 297

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Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated

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