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User

'

s Guide

SLUU439A

August 2010

Revised May 2011

bq24725EVM Evaluation Module

This user's guide describes the features and operation of the bq24725EVM Evaluation Module (EVM).
This EVM assists users in evaluation the bq24725 synchronous battery charger. The manual includes the
bq24725EVM bill of materials, board layout, and schematic.

Contents

1

Introduction

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1

2

Test Summary

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3

3

PCB Layout Guideline

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4

Bill of Materials, Board Layouts and Schematics

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8

List of Figures

1

Connections of the EV2300 Kit

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4

2

Original Test Setup for HPA-542 (bq24725 EVM)

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5

3

Main Window of the bq24725 Evaluation Software

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5

4

Test Setup for HPA-542

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7

5

Top Layer

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10

6

Second Layer

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10

7

Third Layer

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11

8

Bottom Layer

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9

Top Mask

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12

10

Bottom Mask

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12

11

Top Silkscreen

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12

Bottom Silkscreen

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13

Top Assembly

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14

14

Bottom Assembly

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14

List of Tables

1

bq24275EVM and EV2300 Connections

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4

2

Bill of Materials

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8

1

Introduction

1.1

EVM Features

Evaluation module for bq24725

High-efficiency NMOS-NMOS synchronous buck charger with 750-kHz frequency

High-efficiency and low-cost NMOS power path selector and integrated gate driver

User-selectable 2-cell, 3-cell, or 4-cell Li-ion battery voltage

Programmable battery voltage, charge current, and ac adapter current via SMBus interface

Flexible Chargeoption() register control via SMBus interface

AC adapter operating range 9 V

24 V

Test points for key signals available for testing. Easy probe hook-up

Windows is a trademark of Microsoft Corporation.

1

SLUU439A

August 2010

Revised May 2011

bq24725EVM Evaluation Module

Submit Documentation Feedback

Copyright

©

2010

2011, Texas Instruments Incorporated

Summary of Contents for bq24725EVM

Page 1: ...2 10 Bottom Mask 12 11 Top Silkscreen 13 12 Bottom Silkscreen 13 13 Top Assembly 14 14 Bottom Assembly 14 List of Tables 1 bq24275EVM and EV2300 Connections 4 2 Bill of Materials 8 1 Introduction 1 1 EVM Features Evaluation module for bq24725 High efficiency NMOS NMOS synchronous buck charger with 750 kHz frequency High efficiency and low cost NMOS power path selector and integrated gate driver Us...

Page 2: ...r overload High accuracy current sense amplifiers enable accurate measurement of the ac adapter current allowing monitoring of overall system power For details see bq24725 data sheet SLUS702 1 3 I O Description Jack Description J1 DCIN AC adapter positive output J1 GND AC adapter negative output J2 SYS Connected to system J2 BAT Connected to battery pack J2 GND Ground J3 ACOK ACOK pin J3 IOUT IOUT...

Page 3: ...erve A B Observe if A B occur If they do not occur the unit under test has failed Assembly drawings have location for jumpers test points and individual components 2 2 Equipment 2 2 1 Power Supplies Power Supply 1 PS 1 a power supply capable of supplying 20 V at 5 A is required Power Supply 2 PS 2 a power supply capable of supplying 5 V at 1 A is required Power Supply 3 PS 3 a power supply capable...

Page 4: ...nd is newer do not overwrite the newer file 8 Click Finish 2 3 Equipment Setup 1 Set the power supply 1 for 0 V 100 mVdc with the current limit set to 5 A and then turn off supply 2 Connect the output of power supply 1 in series with a current meter multimeter to J1 DCIN GND 3 Connect a voltage meter across J1 DCIN GND 4 Set the power supply 2 for 3 3 V 100 mVdc 0 2 A 0 1 A current limit and then ...

Page 5: ...puter Open the bq24725 evaluation software The main window of the software is shown in Figure 3 Figure 3 Main Window of the bq24725 Evaluation Software 5 SLUU439A August 2010 Revised May 2011 bq24725EVM Evaluation Module Submit Documentation Feedback Copyright 2010 2011 Texas Instruments Incorporated ...

Page 6: ...inal EVM2300 installation USB port Open the bq24725 evaluation software The main window of the software is shown in Figure 3 3 Type in 512 mA in the Charge Current DAC and click the Write button This sets the battery charge current regulation threshold 4 Type in 12592 mV in the Charge Voltage DAC and click the Write button This sets the battery voltage regulation threshold Measure V J2 BAT 12 6 V ...

Page 7: ...nt meter with PS 3 Make sure a voltage meter is connected across J2 BAT GND Enable the output of the PS 3 Ensure that the output voltage is 10 V 500 mV Measure Measure V J2 SYS 19 5 V 1 V adapter connected to system 3 Turn off PS 1 Measure V J2 SYS 10 V 1 V battery connected to system Measure V J2 BAT 10 V 1 V battery connected to system 3 PCB Layout Guideline The switching node rise and fall time...

Page 8: ...om power ground Connect analog ground and power ground separately Connect analog ground and power ground together using power pad as the single ground connection point Or use a 0 Ω resistor to tie analog ground to power ground power pad must tie to analog ground in this case if possible 9 Decoupling capacitors must be placed next to the IC pins and make trace connection as short as possible 10 It ...

Page 9: ...1 603 Std Std 1 R15 430k Resistor Chip 1 16W 1 603 Std Std 1 R16 10 Resistor Chip 1 4W 1 1206 Std Std 3 R17 R18 10 0k Resistor Chip 1 16W 1 603 Std Std R19 1 R20 100k Resistor Chip 1 16W 1 603 Std Std 1 R21 12 1k Resistor Chip 1 16W 1 603 Std Std 1 R22 316k Resistor Chip 1 16W 1 603 Std Std 1 R23 3 01M Resistor Chip 1 16W 1 603 Std Std 1 R24 10 Resistor Chip 1 16W 1 603 Std Std 1 TP1 131 4244 00 A...

Page 10: ...nd Schematics www ti com 4 2 Board Layouts Figure 5 Top Layer Figure 6 Second Layer 10 bq24725EVM Evaluation Module SLUU439A August 2010 Revised May 2011 Submit Documentation Feedback Copyright 2010 2011 Texas Instruments Incorporated ...

Page 11: ...als Board Layouts and Schematics Figure 7 Third Layer Figure 8 Bottom Layer 11 SLUU439A August 2010 Revised May 2011 bq24725EVM Evaluation Module Submit Documentation Feedback Copyright 2010 2011 Texas Instruments Incorporated ...

Page 12: ... Layouts and Schematics www ti com Figure 9 Top Mask Figure 10 Bottom Mask 12 bq24725EVM Evaluation Module SLUU439A August 2010 Revised May 2011 Submit Documentation Feedback Copyright 2010 2011 Texas Instruments Incorporated ...

Page 13: ...oard Layouts and Schematics Figure 11 Top Silkscreen Figure 12 Bottom Silkscreen 13 SLUU439A August 2010 Revised May 2011 bq24725EVM Evaluation Module Submit Documentation Feedback Copyright 2010 2011 Texas Instruments Incorporated ...

Page 14: ...Figure 13 Top Assembly Figure 14 Bottom Assembly 4 3 Schematics The schematic is shown on the following page 14 bq24725EVM Evaluation Module SLUU439A August 2010 Revised May 2011 Submit Documentation Feedback Copyright 2010 2011 Texas Instruments Incorporated ...

Page 15: ...www ti com Bill of Materials Board Layouts and Schematics 15 SLUU439A August 2010 Revised May 2011 bq24725EVM Evaluation Module Submit Documentation Feedback Copyright 2010 2011 Texas Instruments Incorporated ...

Page 16: ...roduct This notice contains important safety information about temperatures and voltages For additional information on TI s environmental and or safety programs please contact the TI application engineer or visit www ti com esh 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...

Page 17: ...horized for use in safety critical applications such as life support where a failure of the TI product would reasonably be expected to cause severe personal injury or death unless officers of the parties have executed an agreement specifically governing such use Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications and acknowledge ...

Page 18: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Texas Instruments BQ24725EVM 542 ...

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