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User's Guide

SLUU358 – April 2009

1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger

With 50-mA LDO and 2.3-A Production Test Support

This user's guide describes the bq25040 evaluation module (EVM), how to setup the EVM to perform a

stand-alone evaluation or interface with a system or host. The charger is designed to deliver up to 1.1 A of

continuous current to the battery output in the adapter mode, ISET, or current limits the input to either 100

mA or 500 mA when in USB100/500 modes. The charge is programmed from the factory for 0.51 A in

ISET mode. In the Protection Test Support (PTS) mode, the battery output is capable of delivering > 2.3 A

of current for short pulses. The LDO regulator output can deliver up to 50 mA of current.

Contents

1 Introduction ................................................................................................................... 2

2 Considerations When Testing the bq25040 IC .......................................................................... 2

3 Performance Specification Summary ..................................................................................... 2

4 Test Summary ................................................................................................................ 3

4.1 Equipment ........................................................................................................... 3

4.2 Equipment and EVM Setup ........................................................................................ 3

4.3 Test Procedure ...................................................................................................... 3

5 Schematics ................................................................................................................... 6

6 Layout ......................................................................................................................... 7

7 Bill of Materials ............................................................................................................... 8

List of Figures

1 Evaluation Setup Charging Circuit Shown; Pulse Programming Circuit not Shown ................................ 3

2 One-Pulse Programming Shows Change From USB500 to ISET Mode ............................................. 4

3 Two-Pulse Programming Shows Timing of Program Change From 0.4 A to 0.1 A ................................. 5

4 Power-Up Sequence Shows Timing Between Vin, Viset, Vpg, and Vchg. C1: Chg @ JMP1; C4: PG @

JMP8; LEDs Pulled Up to 4.15-V Battery ................................................................................ 5

5 Basic EVM Charger Circuit ................................................................................................. 6

6 Circuit for Programming Pulse (Typically Done by Host) ............................................................... 6

7 Assembly Layer .............................................................................................................. 7

8 Top Copper Layer ........................................................................................................... 7

9 Bottom Copper Layer Bottom View ....................................................................................... 8

List of Tables

1 HPA437A Bill of Materials - bq25040 ..................................................................................... 8

SLUU358 – April 2009 1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.3-A Production Test Support 1

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Summary of content (11 pages)

PAGE 1
User's Guide SLUU358 – April 2009 1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.3-A Production Test Support This user's guide describes the bq25040 evaluation module (EVM), how to setup the EVM to perform a stand-alone evaluation or interface with a system or host. The charger is designed to deliver up to 1.1 A of continuous current to the battery output in the adapter mode, ISET, or current limits the input to either 100 mA or 500 mA when in USB100/500 modes.
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Introduction 1 www.ti.com Introduction The bq25040 is an integrated Li-ion linear battery charger targeted at space-limited portable applications. It operates from either a USB port or ac adapter and charges a single-cell, Li-Ion battery with up to 1.1 A of charge current. The bq25040 has a single-power output that charges the battery. A system load can be placed in parallel with the battery. The charge current is programmed using the ISET and EN/SET inputs.
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Test Summary www.ti.com 4 Test Summary This section covers the setup and tests performed in evaluating the EVM. 4.1 Equipment • • • • • 4.2 Power supply +5.1 ±0.1 V, current limit set to 1.5 ±0.1 A Battery: 4.2 V LiCoO2 or equivalent LDO Load: from 100-Ω to 10k-Ω resistor Three Fluke 75 DMMs (equivalent or better) Oscilloscope, Model TDS220 (equivalent or better) Equipment and EVM Setup • • • • • • • Preset P/S#1 to 5.1 ±0.1 V, 1.5 ±0.
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Test Summary www.ti.com 5. Switch, S1, DOWN, then back UP. The scope captures one pulse on CH2 (Figure 2). The pulse must be less than 1.5-ms wide. If too wide, the potentiometer, R7, can adjust the pulse width. 6. Verify that the input current changes from 0.4 A to 0.51 A (one pulse programmed the IC for ISET mode). The ISET resistor, 1 kΩ, programs the ISET mode to ~0.51 A. Note that the IC can only be programmed once.
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Test Summary www.ti.com Vbat Viset V_0.1 ohm_BAT Ven/set Figure 3. Two-Pulse Programming Shows Timing of Program Change From 0.4 A to 0.1 A Vin Viset C1 C2 C3 Vchg Vpg C4 Figure 4. Power-Up Sequence Shows Timing Between Vin, Viset, Vpg, and Vchg. C1: Chg @ JMP1; C4: PG @ JMP8; LEDs Pulled Up to 4.15-V Battery SLUU358 – April 2009 1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.
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Schematics 5 www.ti.com Schematics Figure 5. Basic EVM Charger Circuit Figure 6. Circuit for Programming Pulse (Typically Done by Host) 6 1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.
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Layout www.ti.com 6 Layout Figure 7. Assembly Layer Figure 8. Top Copper Layer SLUU358 – April 2009 1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.
PAGE 8
Bill of Materials www.ti.com Figure 9. Bottom Copper Layer Bottom View 7 Bill of Materials Table 1.
PAGE 9
Bill of Materials www.ti.com Table 1. HPA437A Bill of Materials - bq25040 (continued) Count RefDes Value Description Size Part Number MFR 1 S1 G12AP Switch, ON-ON Mini Toggle 0.28 0.18 inch G12AP NKK 4 TP1, TP2, TP6, TP10 WHT Test Point, O.032 Hole 5012 Keystone 1 U1 BQ25040DQC IC, 1.
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EVALUATION BOARD/KIT IMPORTANT NOTICE Texas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLY and is not considered by TI to be a finished end-product fit for general consumer use. Persons handling the product(s) must have electronics training and observe good engineering practice standards.
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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 orders and should verify that such information is current and complete.