Texas Instruments BQ24351EVM User Manual

User's Guide

SLUU455–October 2010

bq24351EVM for Li-Ion Charger Front-End Protection IC

This user's guide describes the features, setup, and operation of the bq24351EVM evaluation module. Included are the bill of materials, board layout, and schematic.

Contents

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

1.1 General Description ................................................................................................ 2

1.2 EVM Features ...................................................................................................... 2

1.3 I/O Description ...................................................................................................... 2

1.4 Controls and Key Parameters Setting ........................................................................... 3

1.5 Recommended Operating Conditions ........................................................................... 3

2 Test Summary ............................................................................................................... 3

2.1 Definitions ........................................................................................................... 3

2.2 Equipment ........................................................................................................... 3

2.3 Equipment Setup ................................................................................................... 4

2.4 Procedure ........................................................................................................... 5

3 PCB Layout Guideline ...................................................................................................... 5

4 Bill of Materials, Board Layout, and Schematic ......................................................................... 6

4.1 Bill of Materials ..................................................................................................... 6

4.2 Board Layout ....................................................................................................... 7

4.3 Schematic ......................................................................................................... 11

List of Figures

1 Original Test Setup for HPA666 (bq24351 DSG EVM)................................................................ 4

2 Top Layer .................................................................................................................... 7

3 Bottom Layer ................................................................................................................ 8

4 Top Silk Screen ............................................................................................................. 9

5 Top Assembly.............................................................................................................. 10

6 bq24351 Schematic....................................................................................................... 11

List of Tables

1 Bill of Materials.............................................................................................................. 6

SLUU455–October 2010 bq24351EVM for Li-Ion Charger Front-End Protection IC

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Introduction

1 Introduction

1.1 General Description

The bq24351 evaluation module (EVM) is a complete charger module for evaluating a charger front-end protection and charger solution using the bq24351 and bq2057C devices. It is designed to deliver up to 560 mA of charge current to Li-ion or Li-polymer applications. The charger front-end protection current is designed to 1.2 A.

The bq24351 protects the charging system against three types of failures: input overvoltage when the ac adapter fails to regulate its voltage, load overcurrent when failures such as a short circuit occur in the charging system, and battery overcharge.

For details, see the bq24351 data sheet (SLUSA62).

1.2 EVM Features

• Evaluation module for bq24351 DSG

• Evaluation module for bq2057C charger integrated circuit (IC)

• Input operating range for bq24351 4.5 V–26 V

• Input overvoltage protection.

• Input overcurrent protection.

• Battery overvoltage protection.

• LED indication for status signals.

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

• Jumpers available. Easy to change connections

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1.3 I/O Description

Jack Description

J1–DC+ AC adapter, positive output J1–DC– AC adapter, negative output, ground J2–FAULT Reserved for other ICs J2–VBAT bq24351 VBAT pin J2–GATDRV bq24351 GATDRV pin J2–CHGIN bq24351 CHGIN pin J3–BATEN Reserved for ohter ICs J3–OUT bq24351 OUT pin J3–BAT+ Battery positive output J3–GND Ground J4–BAT+ Connect to battery positive output J4–BAT– Connect to battery negative output, ground

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1.4 Controls and Key Parameters Setting

(1)

Jack

JP1 If on, high-side sensing resistor is disabled Jumper on JP2 Reserved for other ICs Jumper (BATEN, GND) on JP3 bq24351 GATDRV pin Jumper off JP4 bq2057C BAT pin connection to bq24351 Jumper on JP5 bq2057C VCC pin connection to bq24351 Jumper on JP6 bq2057C CC pin connection to bq24351 Jumper on JP7 If on, low-side current-sensing resistor is disabled Jumper off

(1)

Short JP1, JP4, JP5, and JP6, and disconnect JP7 to use onboard bq2057C as charger; to use external charger to control bq24351, disconnect JP1, JP4, JP5, and JP6 and short JP7.

Description Factory Setting

1.5 Recommended Operating Conditions

Symbol Description MIN TYP MAX Unit

Supply voltage, V Battery voltage, V Supply current, I Charge current, I Operating junction temperature range, T

BAT

chrg

Input voltage from ac adapter input 4.5 5 26 V Voltage applied at VBAT terminal of J4 0 3–4.2 5 V Maximum input current from ac adapter input 0 1.5 A Battery charge current 0.05 0.56 1 A

Test Summary

0 125 °C

2 Test Summary

2.1 Definitions

This procedure details how to configure the evaluation board. On the test procedure, the following naming conventions are followed. See the schematic for details.

VXXX External voltage supply name (VIN, VBAT, VOUT) LOADW External load name (LOADR, LOADI) V(TPyyy) Voltage at internal test point TPyyy. For example, V(TP1) means the voltage at

V(Jxx): Voltage at jack terminal Jxx. V(TP(XXXXX)) Voltage at test point XXXXX. For example, V(ACDET) means the voltage at the

V(XXX, YYY) Voltage across points XXX and YYY. I(JXX(YYY)) Current going out from the YYY terminal of jack XX. Jxx(BBB) Terminal or pin BBB of jack xx Jxx ON Internal jumper Jxx terminals are shorted Jxx OFF Internal jumper Jxx terminals are open Jxx (-YY-) ON Internal jumper Jxx adjacent terminals marked as YY are shorted Measure → A,B Check specified parameters A, B. If measured values are not within specified

Observe → A,B Observe if A, B occur. If they do not occur, the unit under test has failed.

TP1.

test point which is marked as ACDET.

limits, the unit under test has failed.

Assembly drawings show locations 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 15 V at 2 A is required.

SLUU455–October 2010 bq24351EVM for Li-Ion Charger Front-End Protection IC

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FAULT

VBAT

GATDRV

CHGIN

BATEN

OUT

BAT+

GND

HPA666 bq24351EVM

JP7

Supply 1

DC+

JP1

BAT+

Ibat

CFET APPLICATION

CIRCUIT

JP6 JP5

JP4

JP3 JP2

Load

Test Summary

2.2.2 Load 1

A 10-V (or above), 2-A (or above) electronic load that can operate in constant-current mode.

2.2.3 Load 2

A 10-V (or above), 2-A (or above) electronic load that can operate in constant-voltage mode.

2.2.4 Meters

Four Fluke 75 multimeters (equivalent or better) Or: Three equivalent voltage meters and one equivalent current meter The current meter must be capable of measuring 2-A+ current.

2.2.5 Wire Gauge

All wires connected to the EVM input power supply and output load must be at least AWG 22. The maximum current is up to 1 A.

2.3 Equipment Setup

1. Set PS 1 for 0 V ±100 mVdc, 2 ± 0.1 A current limit, and then disable the output.

2. Connect the output of PS 1 to J1 (DC+, DC–).

3. Connect a voltage meter across J1 (DC+, DC–).

4. Connect the output of load 1 in series with a current meter (multimeter) to J2 (CHGIN) and J3 (GND).

Turn on the power of load 1. Set the load current to 1.5 A ±50 mA, but disable the output.

5. Connect the output of load 2 in series with a current meter (multimeter) to J4 (BAT+, BAT–).

6. Connect a voltage meter across J4 (BAT+, BAT–).

7. Set the voltage of load 2 to 3.6 V ±0.1 V, and disable output of load 2.

8. JP1: ON, JP2 (BATEN, GND): ON, JP3: OFF, JP4: ON, JP5: ON, JP6: ON, JP7: OFF. After the preceding steps have been taken, the test setup for HPA666 (bq24351 DSG EVM) appears as is

shown in Figure 1.

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Figure 1. Original Test Setup for HPA666 (bq24351 DSG EVM)

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