TEXAS INSTRUMENTS bq241xx Technical data

User’s Guide

Using the bq241xx (bqSWITCHERE)

User’ s Gu ide

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 S TA TUTOR Y, 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 b e r e gulatory 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

DYNAMIC WARNINGS AND RESTRICTIONS

It is important to operate this EVM within the input voltage range of 4.5 V to 16 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 50°C. The EVM is designed to operate properly with certain components above 50°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

SLUU200 − July 2004

Using the bq241xx (bqSWITCHERE)

Portable Powe

Contents

1 Introduction 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2 Test Summary 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 Schematic 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 Physical Layouts 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 List of Materials 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6 References 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 Introduction

This user’s guide describes the bq241xxEVM (bqSWITCHER) Evaluation Module. The EVM provides a convenient method for evaluating the performance of a charge management solution for portable applications using the bq241xx product family. A complete designed and tested charger is presented. The charger is designed to deliver up to 2.0 A of continuous output current. The charger is programmed from the factor to deliver

1.33 A of charging current. Follow the instructions in this user’s guide that pertain to the specific bq241xxEVM to be evaluated (one-, two- or three-cell). Please refer to the bqSWITCHER data sheet (SLUS606) prior to evaluation for detailed information on the bqSWITCHER device.

1.1 Background

The bqSWITCHER series are highly integrated Li-Ion and Li-Pol switch-mode charge management devices targeted at a wide range of portable applications. The bqSWITCHER series offer integrated synchronous PWM Controller and PowerFETs, high-accuracy current and voltage regulation, charge conditioning, charge status, and charge termination, in a small thermally enhanced QFN package. The system-controlled version provides additional input for full charge management under system control.

The bqSWITCHER charges the battery in three phases: conditioning, constant current and constant voltage. Charge is terminated based on user-selectable minimum current level. A programmable charge timer provides a backup safety for charge termination. The bqSWITCHER automatically restarts the charge if the battery voltage falls below an internal threshold. The bqSWITCHER automatically enters sleep mode when V is removed.

supply

Using the bq241xx (bqSWITCHERE)

SLUU200 − July 2004

1.2 Performance Specification Summary

This section summarizes the performance specifications of the EVM. Table 1 gives the performance specifications of the EVM. The TS pin has been disabled, for easier charging evaluation, by fixing its voltage to a set value. See EVM schematic and data sheet for information on how to change R10 and R11 values to use with an external thermistor

SPECIFICATION

Input DC voltage, V Battery charge current

Power dissipation

I(DC)

(1)

, I

O(CHG)

2 Test Summary

Table 1. Performance Specification Summary

TEST CONDITIONS MIN TYP MAX UNIT

bq24100

(1 cell)

bq24103 bq24113

(1 cell)

bq24103 bq24113

(2 cell)

bq24105 bq24115

(1 cell)

bq24105 bq24115

(2 cell)

bq24105 bq24115

(3 cell)

5 V ≤ VIN ≤ 16 V, V

9 V ≤ VIN ≤ 16 V, V

5 V ≤ VIN ≤ 16 V, V

9 V ≤ VIN ≤ 16 V, V

13.5 V ≤ VIN ≤ 16 V, V

(BAT)

= 4.2 V, I

= 8.4 V, I

= 4.2 V, I

= 8.4 V, I

= 12.6 V , I

= 1.33 A 0.6

OUT

= 1.33 A 0.6

OUT

= 1.33 A 0.85

OUT

= 1.33 A 0.6

OUT

= 1.33 A 0.85

OUT

= 1.33 A 1.17

OUT

(1)

+ 0.6 5.0 16 V

REG

1.33 2.0

(1)

This chapter covers the test setups and tests performed, in evaluating the EVM.

2.1 Equipment

Power Source: Current limited 15-V lab supply with its current limit set to 25% above the programmed charging current (1.7 A for setup from factory). This is basically a safety limit. The actual DC input current should be less than the charging current.

D Two Fluke 75: (optional) To measure input and output voltage and drop across current sense resistor.

2.2 Setup

The bq241xx EVM board requires a regulated supply approximately 0.3 V minimum above the regulated voltage of the battery pack (1-cell pack: 4.2 V; 2-cell pack: 8.4 V; 3-cell pack: 12.6 V) to a maximum input voltage of 16 V

A one- to three-cell battery pack is needed for EVM evaluation. The EVM should be chosen and set up to charge the same numbers of cells as the battery pack to be evaluated. See Table 2.

Setup the EVM as shown in Table 2. Preset the input supply to the desired voltage, turn off supply and then connect supply to J1. Set the supply’s current limit 25% above the programmed charging current. The test setup connections and jumper setting selections are configured for a stand-alone evaluation but can be changed to interface with external hardware such as a microcontroller. Refer to schematic and data sheet for additional functional information on other optional connections.

Using the bq241xx (bqSWITCHERE)

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