Texas Instruments bq24187 User Manual

User's Guide

SLUUAI5 –April 2014

bq24187 Evaluation Module User's Guide

The bq24187 evaluation module is a complete charger module for evaluating compact, flexible, highefficiency, USB-friendly, switch-mode charge management solution for single-cell, Li-ion and Li-polymer batteries used in a wide range of portable applications.

Contents

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

1.1 BQ24187 IC Features.............................................................................................. 2

1.2 bq24187EVM Features ............................................................................................ 2

1.3 Schematic............................................................................................................ 3

1.4 I/O Description ...................................................................................................... 4

1.5 Test Points to IC Pins .............................................................................................. 4

1.6 Control and Key Parameters Setting............................................................................. 4

1.7 Recommended Operating Conditions............................................................................ 5

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

2.1 Definitions............................................................................................................ 5

2.2 Recommended Test Equipment .................................................................................. 5

2.3 Recommended Test Equipment Setup .......................................................................... 7

2.4 Recommended Test Procedure................................................................................... 9

3 Printed-Circuit Board Layout Guideline.................................................................................. 10

4 Bill of Materials and Board Layout ...................................................................................... 11

4.1 Bill of Materials .................................................................................................... 11

4.2 Board Layout....................................................................................................... 12

List of Figures

1 bq2418xEVM Schematic.................................................................................................... 3

2 BAT_Load (PR1010) Schematic........................................................................................... 6

3 Connections of HPA172 Kit ................................................................................................ 7

4 Recommended Initial Test Setup for bq24187EVM-625 ............................................................... 8

5 Main Window of BQ24187SW Evaluation Software..................................................................... 8

6 Top Assembly Layer ....................................................................................................... 12

7 Top Layer ................................................................................................................... 13

8 First Internal Layer ......................................................................................................... 14

9 Second Internal Layer ..................................................................................................... 15

10 Bottom Layer................................................................................................................ 16

List of Tables

1 Bill of Materials - PWR625A ............................................................................................. 11

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Introduction

1 Introduction

1.1 BQ24187 IC Features

The BQ24187 family integrates a synchronous PWM controller, power MOSFETs, input-current sensing, high-accuracy current and voltage regulation and charge termination into a small WCSP package. The charge parameters can be programmed through an I2C interface. Key IC features include:

• High-efficiency, fully integrated, NMOS-NMOS, synchronous buck charger with 1.5-MHz frequency

• Charge time optimizer

• Integrated power FETs for up to 2-A charge rate

• 5-V, 1-A on-the-go (OTG) VBUS supply For details, see the bq24187 data sheet (SLUSBM0).

1.2 bq24187EVM Features

The bq24187 evaluation module (EVM) provides a complete charger module for evaluating compact, flexible, high-efficiency, USB-friendly, switch-mode battery charge solutions for single-cell, Li-ion and Lipolymer battery-powered systems used in a wide range of portable applications. Key EVM features include:

• Terminal blocks and standard headers for IN, BAT, TS; USB connector for IN

• Programmable battery voltage, charge current, input current, and status via I2C interface

• IN operating up to 6.0 V

• LED indication for status signals

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

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J10

BAT

DRV

JP6

HIGH

up to 4.44V, 2A

PSEL

BAT

LOW

Open

J11

GND

BAT

GND

BQ24187YFF

PGND

PMID

BOOT

SDA

SCL

DRV

STAT

INT

CS+

AGND

BAT

PSEL

BQ2418XYFF

1.0uF

GND

JP1

USB

GND

PSEL

1.0uF

GND

22uF

up to 6V, 2.5A

GND

INT

STAT

DRV

1.0uF

4.7uF

Open

PSEL

GND

SCL

GND

SDA

GND

0.033uF

GND

DRV

1.5 uH

DRV

JP4

HIGH

DRV

LOW

DRV

GND

EXT

.62k

TP9

GND

DRV

GND

JP5

EXT

JP2

JP3

TP10

SCL

SIM

1 2 3 4 5 6 7 8 9

J12

12.4k

STAT

GND

INT

TP1TP2 TP3TP4 TP5 TP7

GNDSWGND

200

TP11

BAT SDA

GND

CS+

50K

GND

1.50k

TP6 TP8

INTSTAT

200

CS+

GND

1 1

1 See BOM for values

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Introduction

1.3 Schematic

Figure 1 illustrates the bq2418x EVM schematic.

Figure 1. bq2418xEVM Schematic

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Introduction

1.4 I/O Description

Header/Terminal Block Description

J1– IN/GND Input power positive and negative terminal J2 – USB USB miniconnector J3 - GND DRV linear regulator negative header J4 - IN Input power positive header J5 - GND Battery negative header J6 - DRV DRV linear regulator positive output J7 - DRV/GND DRV linear regulator positive and negative terminals J8 - GND Input power negative header J9 - EXT TS/GND External thermistor terminal J10 - GND Battery positive header J11 - BAT/GND Battery positive and negative terminal J12 - USB-TO-GPIO USB-TO-GPIO box keyed connector

1.5 Test Points to IC Pins

Test Point Description

TP1 BAT TP2 SW TP3 GND TP4 CS+ TP5 GND TP6 STAT TP7 GND TP8 INT TP9 TS TP10 SCL TP11 SDA

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1.6 Control and Key Parameters Setting

Jumper Description Default Factory Setting

JP1 N/A Not installed JP2 Shorting jumper to connect DRV to annode of D1 STAT LED SHORTED JP3 Shorting jumper to connect DRV to annode of D1 INT LED SHORTED

JP4 CD = LO

JP5 TS=SIM

JP6 PSEL = HIGH: Default mode input current limit is set to 100 mA until changed by I2C. PSEL = LOW

bq24187 Evaluation Module User's Guide SLUUAI5 –April 2014

CD = LO: Charge disable low for normal operation CD = HI: Charge disable high to disable the buck converter and enter Hi-Z mode

TS = SIM: Connects a potentiometer to the TS pin so that the potentiometer can simulator a thermistor. The potentiometer is preset per R5 and R6 so that the TS voltage is 0.5 x V (DRV). TS = EXT: Connects the TS pin to an external thermistor through J9. The resistor divider formed by R5 and R6 is sized to accommodate a 10-kΩ thermistor. If a different thermistor is used, R5 and R6 must be resized.

PSEL = LOW: Input current limit is set to 1.5 A until changed by I2C. Default mode input current limit is set to 1.5 A until changed by I2C.

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1.7 Recommended Operating Conditions

Supply voltage, V Battery voltage, V

Supply current, I

Fast charge current, Battery charge current (registers set via I2C communication) 0.500 2.0 A I

CHRG(MAX)

Operating junction temperature range, T

BAT

IN(MAX)

Input voltage from ac adapter (bq24262) 4.2 6.0 V Voltage output at VBAT terminal (registers set via I2C 3.5 4.2 4.44 V

communication) Maximum input current from ac adapter input (registers set 0.1 2.0 A

via I2C communication)

2 Test Summary

This procedure describes one test configuration of the HPA721 evaluation board for bench evaluation.

2.1 Definitions

The following naming conventions are followed.

VXXX : External voltage supply name (VADP, VBT, VSBT) LOADW: External load name (LOAD1, LOAD2) V(TPyyy): Voltage at internal test point TPyyy. For example, V(TP12) means the voltage at

TP12. V(Jxx): Voltage at header Jxx V(TP(XXX)): Voltage at test point XXX. For example, V(ACDET) means the voltage at the test

point which is marked as ACDET. V(XXX, YYY): Voltage across point XXX and YYY I(JXX(YYY)): Current going out from the YYY terminal of header XX Jxx(BBB): Terminal or pin BBB of header xx JPx ON : Internal jumper Jxx terminals are shorted JPx OFF: Internal jumper Jxx terminals are open JPx (-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 limits,

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

Introduction

Min Typ Max Unit

-40 125 °C

Assembly drawings have locations for jumpers, test points, and individual components.

2.2 Recommended Test Equipment

2.2.1 Power Supplies

1. A power supply #1 (PS #1) capable of supplying 5 V at 2.5 A, is required.

2. If not using a battery as the load, then power supply #2 (PS #2) capable of supplying up to 5 V at 5 A is required to power the circuit shown in Figure 2.

2.2.2 Load #1 Between BAT and GND

Testing with an actual battery is the best way to verify operation in the system. If a battery is not available, then a circuit similar to the one shown in Figure 2 can simulate a battery when connected to a power supply. Alternatively, a sourcemeter, capable of sourcing and sinking current can be used to simulate a battery.

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Test Summary

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Figure 2. BAT_Load (PR1010) Schematic

2.2.3 Meters

Four equivalent voltage meters (VM #) and two equivalent current meters (CM #) are required. The current meters must be able to measure 3-A current.

2.2.4 Computer

A computer with at least one USB port and a USB cable is required. The BQ24187 evaluation software must be properly installed.

2.2.5 HPA172 Communication Kit (USB TO GPIO)

An HPA172 USB-to-I2C communication kit is required.

2.2.6 Software

Download BQ24187SW.zip from the charger's product folder, unzip the file, and double-click on the SETUP.EXE file. Follow the installation steps.

Because the bq24187 has a watchdog timer, it is recommended that you set the software's Reset Watchdog Timer to reset every 5 seconds. Otherwise, after 30 seconds of operation, the IC enters Default mode. Note that the 27-minute safety timer is not reset by this function and eventually times out if charging does not complete, unless the Safety Timer Time Limit is expanded or disabled via the GUI. One way to reset the safety timer is to allow the 30-second watchdog timer to expire. See Figure 3 in the data sheet for more information about the timers.

Also, it is generally helpful to activate the Write On Change functions, in the upper left of the GUI window, to ON. The Write On Change function writes any changes to the GUI's check boxes, drop-down boxes, and registers to the IC. Otherwise, the user must click the WRITE button to write changes to the software. It is recommended that the user periodically click the READ button to find the IC's instantaneous status. Alternatively, the AutoRead function can be activated to periodically update the GUI with the IC's status.

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To Computer USB port

USB Interface

Adapter

I/O

USB

TexasInstruments

©2006

10-pin Ribbon Cable

To EVM

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2.3 Recommended Test Equipment Setup

1. For all power connections, use short, twisted-pair wires of appropriate gauge wire for the amount of the current.

2. Set PS #1 for 5-V, 2.5-A current limit and then turn off supply.

3. Connect the output of PS #1 in series with a current meter (CM #1) to J1 (IN).

4. Connect a voltmeter (VM #1) across J4 and J3 (IN and GND).

5. If BAT_Load as shown in Figure 1 is used, connect PS #2, set to approximately 3.7 V, to the input side (PS #2+/-) of BAT_Load, then turn off PS #2.

6. Connect the output side of the battery or BAT_Load in series with current meter (multimeter) #2 (CM #2) to J11 and J10 or J5 (BAT, GND). Ensure that a voltage meter (VM #2) is connected across J10 or TP1 and J5 or TP7 (BAT and GND).

7. Connect VM #3 across J6 and J8 (DRV and GND).

8. Connect the HPA172 kit to J12 by the 10-pin ribbon cable. Connect the USB port of the HPA172 kit to the USB port of the computer. The connections are shown in Figure 3.

Test Summary

Figure 3. Connections of HPA172 Kit

9. Ensure jumpers are at the settings highlighted in yellow (except for JP1 which is not installed) per

Section 1.6.

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Texas Instruments bq24187 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual