Texas Instruments bq26231EVM-001 User manual


     
July 2002 PMP
User’s Guide
SLUU126

IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
ordersandshouldverifythatsuchinformationiscurrentandcomplete.AllproductsaresoldsubjecttoTI’sterms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TIdoesnotwarrantorrepresentthatanylicense, eitherexpress orimplied, isgranted underanyTIpatentright,
copyright,maskworkright,orotherTIintellectualpropertyrightrelatingtoanycombination,machine,orprocess
inwhichTIproductsorservicesareused.InformationpublishedbyTIregardingthird–partyproductsorservices
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2002, Texas Instruments Incorporated

EVM IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:
Thisevaluationkit being soldbyTI is intendedforuse 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.
ShouldthisevaluationkitnotmeetthespecificationsindicatedintheEVMUser’sGuide,thekitmaybereturned
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,ORSTATUTORY,INCLUDINGANYWARRANTY OF MERCHANTABILITY ORFITNESSFORANY
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
receivedmaynotberegulatorycompliant oragency certified (FCC,UL, CE,etc.). Dueto theopen construction
oftheproduct,itistheuser’sresponsibilitytotakeanyandallappropriateprecautionswithregardtoelectrostatic
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’sGuidepriortohandlingtheproduct.Thisnoticecontainsimportantsafetyinformationabouttemperatures
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 2002, Texas Instruments Incorporated

EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the input voltage range of 2.8–5.5 V and the output
voltage range of 2.8–5.5 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.
Applyingloadsoutsideofthespecifiedoutputrangemayresultinunintendedoperationand/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.
Duringnormaloperation,somecircuitcomponentsmayhavecasetemperaturesgreaterthan
70°C.TheEVM isdesignedto operateproperlywith certaincomponentsabove 70°C aslong
astheinputandoutput rangesare maintained.Thesecomponentsincludebut arenot limited
tolinearregulators,switchingtransistors,passtransistors,andcurrentsenseresistors.These
typesof devicescanbeidentifiedusingtheEVM schematiclocated intheEVMUser’sGuide.
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 2002, Texas Instruments Incorporated

Contents
iii
Contents
1 Introduction 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1 Features 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Kit Contents 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Ordering Information 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Circuit Module 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 Pin Descriptions 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Schematic 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Board Layout 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Bill of Materials 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 Performance Specifications 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 EVM Hardware and Software Setup 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Software Installation 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Hardware Connection 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1 Connecting the bq26231EVM-001 Circuit Module to a Battery Pack 3-2. . . . . . . .
3.2.2 PC Interface Connection 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Operation 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1 Software Installation 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Starting the Program 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 Software Instructions 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3.1 bq26231 Registers Screen 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3.2 Graphs Screen 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3.3 Read/Write Regs Screen 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3.4 Setup Screen 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4 Data Logging 4-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contents
iv
Figures
2–1 bq26231EVM-001 Schematic 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2 bq26231EVM-001 Circuit Module Layout 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1 bq26231EVM-001 Circuit Module Connection to Cells and System Load/Charger 3-2. . . . .
4–1 Initial Register Screen 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–2 Loading Screen That Shows the Board Detection Is Failing 4-4. . . . . . . . . . . . . . . . . . . . . . . . .
4–3 Graph Screen 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–4 Read/Write Regs. Screen 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–5 Setup Screen 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–6 Data Logging Screen 4-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–7 Example of Data Logged Screen 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tables
1–1 Ordering Information 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–1 Bill of Materials 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2 Performance Specification Summary 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1 Circuit Module-to-EV2200 Connection 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1
Introduction
The bq26231EVM–001 is a complete evaluation system for the battery
monitoring IC bq26231. The EVM includes one bq26231 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 bq26231 and
allothercomponentsonboard necessarytomonitorcapacityand othercritical
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
EV2200–231 software, the user can read the bq26231 data registers and
evaluate the functions of the bq26231 under different charge and discharge
conditions.
Topic Page
1.1 Features 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Kit Contents 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Ordering Information 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1

Features
1-2
1.1 Features
-Complete evaluation system for the bq26231 battery monitor IC
-Populated circuit module for quick setup
-PC software and interface board for easy evaluation
-Software that allows data logging for system analysis
1.2 Kit Contents
-bq26231 circuit module with sense resistor
-EV2200 PC interface board
-Set of evaluation software disks entitled EV220–231
-PC serial cable
-Set of support documentation
1.3 Ordering Information
Table 1–1.Ordering Information
EVM Part Number Additional ICs Chemistry Pack Voltage Capacity
bq26231EVM–001 None Li-Ion/NiMH/NiCd 2.8–5.5 V Any

2-1
Circuit Module
Circuit Module
The bq26231EVM-001 based circuit module is a complete and compact
example of a circuit for battery monitoring of a single-cell Li-Ion pack. The
circuit module incorporates a bq26231 battery monitor IC and all other
components necessary to accurately protect and monitor the charge and
discharge of single 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, serial
communications port, system load, and charger.
Topic Page
2.1 Pin Descriptions 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Schematic 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Board Layout 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Bill of Materials 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 Performance Specifications 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 2

2-2
2.1 Pin Descriptions
BAT+ Cell positive/pack positive (PACK+)
BAT_ Cell negative
PACK–Pack negative
HDQ Serial communications port
RBI Register backup input
2.2 Schematic
Figure 2–1 is the bq26231EVM-001 (SLUP148) circuit module schematic
diagram.
Figure 2–1.bq26231EVM-001 Schematic
R3
100 kΩ
NC
21
U1
bq26230PW/
bq26231PW
BAT+ RBI
D2
J2
100 kΩ
R6 BAT–
NC
D1
5.6 V
R3
100 ΩPACK–
C4
0.1 µf
R7
1 M
HDQ
J1
1
R1
100 Ω
C1
0.1 µf
R5
100 kΩ
R2
100 Ω
VCC
VSS
HDQ
SR1
SR2
RBI R8
0.02
C3
0.1 µf
C2
0.1 µf
2
3
4
8
7
6
5

Board Layout
2-3
Circuit Module
2.3 Board Layout
Figure 2–2 shows the PCB layers and assembly drawing for the
bq26231EVM-001 circuit module (SLUP148).
Figure 2–2.bq26231EVM-001 Circuit Module Layout
U1
TEXAS INSTRUMENTS SLUP148 A
TOP ASSEMBLY
44.45
R1
R3 C1
10.80
J2 C4 R5 R6
C2 C3 J1
1
44.45
D2
R7
R4
R2
R8 D1
10.80
TEXAS INSTRUMENTS SLUP148 A
BOTTOM ASSEMBLY
TEXAS INSTRUMENTS SLUP148 REV. A 4.06
25.40
J2 J1
SILK 1

Board Layout
2-4
Figure 2–2. bq26231EVM-001 Circuit Module Layout (Continued)
TEXAS INSTRUMENTS SLUP148 REV. A
LAYER 1
TEXAS INSTRUMENTS SLUP148 REV. A
LAYER 2
TEXAS INSTRUMENTS SLUP148 REV. A
MASK 1
TEXAS INSTRUMENTS SLUP148 REV. A
MASK 2

Bill of Materials
2-5
Circuit Module
2.4 Bill of Materials
Table 2–1 lists materials required for the bq26231EVM-001 circuit module.
Table 2–1.Bill of Materials
Ref Des Qty–002 Description MFG MFG Part No. Size
PCB 1 Printed circuit board, 0.031,
FR4, SMOBC, HASl Any See FAB DWG
Terminal 2 Terminal block 3,5 mm On Shore ED555/2DS 3,5 mm ×2
C1, C2, C3, C4 4Capacitor, ceramic, 0.1 µF,
16 V, ±10%, X7R Panasonic ECJ-1VB1C1104K 603
R1 1 Resistor, 1 MΩ, 1/16 W, 5% Panasonic ERJ-3GSYJ105 603
R8 1 Resistor, 0.020 Ω, 1/2 W, 1% IRC LR2010-01-R020-F 2010
R3, R5, R6 3Resistor, 100 kΩ, 1/16 W, 5% Panasonic ERJ-3GSYJ104 603
R1, R2, R4 3Resistor, 100 Ω, 1/16 W, 5% Venkel ERJ-3GSYJ101 603
D1 1 Diode, zener, 5.6 V Zetex BZX84C5V6 SOT-23
D2 1 Diode, 1N914 Diode Inc. MMBD914 SOT-23
U1 1 Integrated circuit, gas gauge,
bq26231PW Benchmarq/TI bq26231PW TSSOP-8
Component count 18
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 Specifications
Table 2–2 summarizes the performance specifications of the
bq26231EVM-001 circuit module (SLUP148). Table 2–2 gives the
performance specifications of the circuit.
Table 2–2.Performance Specification Summary
Specification MIN TYP MAX UNIT
Input voltage BAT+/BAT–2.8 5.5 V
Charge and discharge current 4 A
Note: Charge and discharge current. maximums are limited by the PCB design and power
dissipation of the 20-mΩ, 0.5-W sense resistor on the PCB.

2-6

3-1
EVM Hardware and Software Setup
EVM Hardware and Software Setup
This section describes how to install the EV2200-231 PC software and how
to connect the components of the EVM.
Topic Page
3.1 Software Installation 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Hardware Connection 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 3

Software Installation
3-2
3.1 Software Installation
The following steps install the EV2200–231 software:
1) Insert disk 1 into a 3 1/2 inch floppy drive.
2) Select the 3 1/2 inch drive using My Computer or Windows Explorer.
3) Double-click the Setup.exe icon.
4) The setup program prompts for the remaining disks and installs a
Windows application group.
3.2 Hardware Connection
There are three hardware components to the bq26231EVM-001:
1) bq26231EVM-001 circuit module
2) EV2200 PC interface board
3) PC
3.2.1 Connecting the bq26231EVM-001 Circuit Module to a Battery Pack
Figure 3–1 shows how to connect the bq26231EVM-001 circuit module to a
Li-Ion cell and the system load/charger.
Figure 3–1.bq26231EVM-001 Circuit Module Connection to Cells and System
Load/Charger
Cell
Load
bq26231EVM-001
Circuit Module
Charger
PACK
BAT–
PACK–
BAT
PACK
PACK–
Battery Pack

Hardware Connection
3-3
EVM Hardware and Software Setup
3.2.2 PC Interface Connection
The following steps configure the hardware for interface to the PC:
1) Connect bq26231EVM-001 to the EV2200 using wire leads as shown in
Table 3–1.
Table 3–1.Circuit Module-to-EV2200 Connection
bq26231 Based Battery EV2200
HDQ SMBD/HDQ1
PACK–VSS
2) Connect the PC serial cable to the EV2200 and the PC COM port.
The bq26231EVM–001 is now set up for operation.

3-4

4-1
Operation
Operation
This chapter details the installation operation of the EVM2200-231 software.
Topic Page
4.1 Software Installation 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Starting the Program 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 Software Instructions 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4 Data Logging 4-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 4

Software Installation
4-2
4.1 Software Installation
The following steps install the EV2200–231 software:
1) Insert disk 1 into a 3 1/2 inch floppy drive.
2) Select the 3 1/2 inch drive using My Computer or Windows Explorer.
3) Double-click the Setup.exe icon.
4) The setup program prompts for the remaining disks and installs a
Windows application group.
4.2 Starting the Program
The installation process creates an icon labeled EV2200-231. Find this icon
and double-click it. Run this EV2200-231 from the Start|Programs|Texas
Instruments menu sequence. The software defaults to PC com port 1 for
communication.Theevaluation software loadsin3to 10 seconds, depending
on the speed of the PC. During this time the EV2200 software is testing the
communications to the EV2200. The subsequent message indicates the
boardstatus.Afterthecommunicationsportisdetected,the softwaredisplays
the bq26231 Registers screen. See Figure 4–1.
If bq26231 Registers screen is not displayed, then the software is not
communicating with the EV2200 interface board. In such case, you will see a
windowasinFigure4–2whenyoufirstclickedontheEV2200-231icon,which
indicates that the serial link is not connected correctly. Secure the serial cable
connection at the EV2200 and the PC and check with the computer manual
to verify the com port selection. Once an appropriate com port is selected, the
program loads the initial register screen.