Texas Instruments BQ24450EVM User Manual

Size:
257.78 Kb
Download

User's Guide

SLUU464 – November 2010

bq24450EVM

This user'sguide describes the features and operation of the bq24450EVM Evaluation Module (EVM). This EVM assists users in evaluating the bq24450 linear battery charger. The manual includes the bq24450EVM bill of materials, board layout, and schematic.

 

 

Contents

 

1

Introduction ..................................................................................................................

2

 

1.1

EVM Features ......................................................................................................

2

 

1.2

General Description ................................................................................................

2

 

1.3

I/O Description and Jumper Functions ..........................................................................

2

 

1.4

Recommended Operating Conditions ...........................................................................

3

2

Equipment ....................................................................................................................

3

 

2.1

Power Supplies .....................................................................................................

3

 

2.2

Loads ................................................................................................................

3

 

2.3

Meters ...............................................................................................................

3

3

Equipment Setup ............................................................................................................

3

4

Procedure ....................................................................................................................

4

 

4.1

Pre-charge ..........................................................................................................

4

 

4.2

Max Charge .........................................................................................................

4

 

4.3

Charge Termination ................................................................................................

4

 

4.4

Re-Charge ..........................................................................................................

4

5

Functions and Features ....................................................................................................

5

 

5.1

Changing Output Voltage and Charge Current ................................................................

5

 

5.2

Options for External Transistor ...................................................................................

6

 

5.3

Other Options .......................................................................................................

6

6

PCB Layout Guideline ......................................................................................................

6

7

Bill of Materials, Board Layouts and Schematic ........................................................................

7

 

7.1

Bill of Materials .....................................................................................................

7

 

7.2

Board Layout .......................................................................................................

8

 

7.3

Schematic ...........................................................................................................

9

 

List of Figures

 

1

Original Test Setup for HPA691 (bq24450 EVM).......................................................................

3

2

Battery Load Circuit – PR1010-2 .........................................................................................

4

3

Calculating the Value of ITAPER .............................................................................................

5

4

Top Assembly Layer........................................................................................................

8

5

Top PCB Layer ..............................................................................................................

8

6

Bottom PCB Layer ..........................................................................................................

9

7

bq24450 EVM Schematic ..................................................................................................

9

 

 

List of Tables

 

1

I/O Description...............................................................................................................

 

2

2

Recommended Operating Conditions ....................................................................................

 

3

3

Bill of Materials ..............................................................................................................

 

7

 

 

 

SLUU464–November2010

bq24450EVM

1

Submit Documentation Feedback

 

 

© 2010, Texas Instruments Incorporated

Introduction

www.ti.com

1 Introduction

1.1EVM Features

Evaluation module for bq24450 (HPA691)

Charge controller for lead-acidbatteries

Constant current and constant voltage modes

Accommodates external transistor in DPAK or TO-220package

Programmable charge current

Pre-Chargefor deeply discharged batteries

1.2General Description

The bq24450 contains all the necessary circuitry to optimally control the charging of lead-acidbatteries. The IC controls the charging current as well as the charging voltage to safely and efficiently charge the battery, maximizing battery capacity and life. Depending on the application, the IC can be configured as a simpleconstant-voltagefloat charge controller or adual-voltagefloat-cum-boostcharge controller.

The built-inprecision voltage reference is especiallytemperature-compensatedto track the characteristics oflead-acidcells, and maintains optimum charging voltage over an extended temperature range without using any external components. The low current consumption of the IC allows for accurate temperature monitoring by minimizingself-heatingeffects.

The IC can support a wide range of battery capacities and charging currents, limited only by the selection of the external pass transistor. The versatile driver for the external pass transistor provides at least 25mA of base drive.

In addition to the voltageand current-regulatingamplifiers, the IC features comparators that monitor the charging voltage and current. These comparators feed into an internal state machine that sequences the charge cycle. Some of these comparator outputs are made available as status signals at external pins of the IC. These status and control pins can be connected to a processor, or they can be connected up in flexible ways for standalone applications.

1.3I/O Description and Jumper Functions

 

 

Table 1. I/O Description

 

 

 

Header

 

Description

 

 

 

 

J1

– Vin

 

Power Supply Positive

 

 

 

 

J2

– GND

 

Power Supply Negative

 

 

 

 

J3

– GND

 

Ground

 

 

 

 

J4

– Vout

 

Connected to Battery/System Load

 

 

 

 

J5

– GND

 

Ground

 

 

 

 

Jumper

Description See Functions and Features section for more information.

JP1

Connects ISNSM for current sense for ITAPER. It can connect ISNSM to either side of the sense

 

resistor, R4.

JP2

Connects IFB for current sense for IMAX. It can connect IFB to either side of the sense resistor, R4.

JP3

Selects the topology for the external transistor. The external transistor can be configured for

 

either Common-Emittertopology orQuasi-Darlingtontopology.

2

bq24450EVM

SLUU464–November2010

 

 

Submit Documentation Feedback

© 2010, Texas Instruments Incorporated

www.ti.com

Equipment

1.4Recommended Operating Conditions

Table 2. Recommended Operating Conditions

Symbol

Description

Min

Typ

Max

Unit

 

 

 

 

 

 

Vin, J1

Supply Voltage

9.5

10.0

10.5

V

 

 

 

 

 

 

Vout, J4

Battery Voltage (3-celllead-acidbattery)

4

 

7.5

V

 

 

 

 

 

 

Iin

Supply Current

0

 

0.5

A

 

 

 

 

 

 

Iout

Charge Current

0

 

0.5

A

 

 

 

 

 

 

2 Equipment

2.1Power Supplies

Power Supply #1 (PS#1): Adjustable from 0 to ≥ 10 VDC at ≥ 1A; used for input J1.

Power Supply #2 (PS#2): Adjustable from 0 to ≥ 10 VDC at ≥ 1.5A; used for Battery Load Board.

2.2Loads

Load #1: Battery Load Circuit Board, PR1010-2,as shown inFigure 2.

2.3Meters

Three Fluke 75 DMMs (equivalent or better).

3Equipment Setup

The original test setup of HPA691 is shown in Figure 1.

1.Set the PS #1 for 10V, 1A current limit and then turn off supply. Connect PS#1 across J1, J2 (VIN, GND).

2.Connect a voltage meter (VM #1) across J1, J2 (VIN, GND)

3.Set PS#2 to 5.2V and then turn off supply. Connect to the Battery Load Circuit Board (P/S+, P/S–)

4.Connect Load #1 (BAT+, BAT–)across J4, J5 (VOUT, GND).

5.Connect a voltage meter (VM#2) across J4, J5 (VOUT, GND).

6.Connect a voltage meter (VM#3) across sense resistor on Load #1.

7.Verify the jumpers are placed correctly as per, Figure 1.

Figure 1. Original Test Setup for HPA691 (bq24450 EVM)

SLUU464–November2010

bq24450EVM

3

Submit Documentation Feedback

 

 

© 2010, Texas Instruments Incorporated

Procedure

www.ti.com

Replacement circuit for a 3-celllead acid battery. BAT+ to BAT– voltage tracks the power supply input voltage, minus 1 diode drop

Figure 2. Battery Load Circuit – PR1010-2

4 Procedure

4.1Pre-charge

Turn on PS #1, preset to 10 VDC. Verify voltage on VM #1. Turn on PS #2, preset to 5.2 VDC.

Adjust PS #2 such that VM #2 shows 5 VDC.

Using VM #3, measure the voltage across the current sense resistor on Load #1. Multiply this value by a conversion factor of 10A/V. This is the pre-chargecurrent.

4.2Max Charge

Adjust PS #2 such that VM #2 shows 6 VDC.

Using VM #3, measure the voltage across the current sense resistor on Load #1. Multiply this value by a conversion factor of 10A/V. This is the max charge current.

4.3Charge Termination

Adjust PS #2 such that VM #2 shows 7.5 VDC. There should be no charge current in this condition.

4.4Re-Charge

Adjust PS #2 such that VM #2 shows 6 VDC.

Using VM #3, measure the voltage across the current sense resistor on Load #1. Multiply this value by a conversion factor of 10A/V. This is the max charge current.

4

bq24450EVM

SLUU464–November2010

 

 

Submit Documentation Feedback

© 2010, Texas Instruments Incorporated

www.ti.com

Functions and Features

5 Functions and Features

5.1Changing Output Voltage and Charge Current

This EVM is configured to charge a 3-CellLead Acid Battery with a maximum charge current of 450 mA. The EVM can be altered to charge lower or higher voltage batteries and can also be altered to have a lower or higher maximum charge current.

Power Dissipation

It is important to monitor the power dissipation in the external transistor, Q1.

WARNING

Q1 and the surrounding area of the PCB may become hot.

(Power Dissipation in Q1) = (Vin – Vout – 0.25 – 0.7) × Charge Current

With a large difference between Vin and Vbat, and/or a high charge current, there will be a significant amount of power dissipation in Q1. This causes both Q1 and the surrounding PCB to get hot. If any alterations are made to the EVM circuit, it is important to ensure a safe level of power dissipation in the external FET, Q1.

Changing Output Voltage

The output voltage may be altered by changing some on-boardresistors (R7, R8, R9, R11, R12). See the bq24450 datasheet for information on how to size these resistors. If Vout is changed, Vin must also be changed. Vin should be high enough to allow for the necessary dropout (across R2, R4, Q1, and D1) and low enough to maintain a safe level of power dissipation.

Changing the Maximum Charge Current

The maximum charge current is set by sense resistor, R2. (Max Charge Current) = (0.25) / R2. Resistor R2 may be adjusted to set a different max charge current. However, more current will yield higher power dissipation in Q1. This may cause the board to become hot.

Changing Pre-ChargeCurrent

Pre-Chargecurrent is set by R10.

Pre-ChargeCurrent = (Vin – 2 – Vout) / R10

Changing the value of Itaper

As populated, ITAPER is 10% ofIMax-Chg.This is because VILIM is 250mV and VISNS is 25mV and both are being sensed across R2. If a different value of ITAPER is desired, R4 can be populated (with anon-zeroresistor) and JP1 and JP2 can be used to connect pins ISNSM and IFB to opposite sides of R4. See figure below.

Figure 3. Calculating the Value of ITAPER

SLUU464–November2010

bq24450EVM

5

Submit Documentation Feedback

 

 

© 2010, Texas Instruments Incorporated

PCB Layout Guideline

www.ti.com

5.2Options for External Transistor

Using a Transistor in a TO-220package

The EVM is populated with a DPAK transistor for Q1. However, if desired, a TO-220transistor can be used instead. Three holes have been placed in the PCB in parallel with the DPAK pad. Remove the DPAK transistor and replace it with aTO-220transistor. The top hole is the base, the middle hole is the collector, and the bottom hole is the emitter.

Using a P-channelFET

The EVM is populated with a PNP transistor for Q1. However, if desired, a P-channelMOSFET may be used instead. In order to use aP-FET,a resistor must be populated on R5. Pin 16 of the BQ24450 will sink current through R5 and generate a negative gate to source voltage for theP-FET.By varying the sink current (and subsequently Vgs), the IC can accurately control the charge current. A 1kΩ resistor is suitable for R5.

Changing the topology

The EVM is configured with the Common-EmitterPNP topology. However, it can also be configured for the PNP in aQuasi-Darlingtonas described on page 13 of the datasheet. To make this change, the following steps should be taken:

1.Place jumper on JP3 such that it connects Pin 15 of the IC to the collector of Q1.

2.Remove R6 and replace with Rp as calculated on page 13 of the data sheet.

5.3Other Options

Disabling Pre-ChargeMode

The EVM is populated to perform pre-chargeon a deeply depleted battery. Ifpre-chargemode is not desired, it can be disabled by performing the steps below.

1.Populate R1 = 0 Ω

2.Remove R11 and R12

3.Populate R14 = R11 + R12 (For example: If R11 = 75kΩ and R12 = 16.9kΩ, R14 = 91.9kΩ)

PGOOD

As populated, the EVM uses PGOOD as part of the feedback divider (explained on page 11 of data sheet). If desired, PGOOD can be used to indicate the supply status on pin 5.

1.Remove R8 and place it on R15 pad.

2.Populate R13 with a pull-upresistor.

6PCB Layout Guideline

It is important to pay special attention to the printed-circuitboard (PCB) layout. The following provides some guidelines:

1.All low-currentGND connections must be kept separate from thehigh-currentcharge or discharge paths from the battery. Use asingle-pointground technique incorporating both the small signal ground path and the power ground path.

2.The high current charge paths into IN pin and from the OUT pin must be sized appropriately for the maximum charge current in order to avoid voltage drops in these traces.

6

bq24450EVM

SLUU464–November2010

 

 

Submit Documentation Feedback

© 2010, Texas Instruments Incorporated

www.ti.com

Bill of Materials, Board Layouts and Schematic

7 Bill of Materials, Board Layouts and Schematic

7.1Bill of Materials

Table 3. Bill of Materials

Reference

Value

Description

Size

Part Number

MFR

Designator

 

 

 

 

 

 

 

 

 

 

 

C1, C4

Open

Capacitor, Ceramic

1206

Std

Std

 

 

 

 

 

 

C2, C5

1.0µF

Capacitor, Ceramic, 25V, X5R, 10%

603

Std

Std

 

 

 

 

 

 

C3

0.1µF

Capacitor, Ceramic, 25V, X7R, 10%

603

Std

Std

 

 

 

 

 

 

D1

ES2AA-13-F

Diode

SMA

ES2AA-13-F

Diodes,

 

 

 

 

 

Inc.

 

 

 

 

 

 

Q1

MJD32CT4

Transistor, PNP

DPAK

MJD32CT4

ST

 

 

 

 

 

 

R1, R5, R13, R14,

Open

Resistor, Chip, 1/16W, 1%

603

Std

Std

R15

 

 

 

 

 

 

 

 

 

 

 

R2

0.56Ω

Resistor, Chip, 1/2W, 1%

2010

STD

STD

 

 

 

 

 

 

R3, R6

Resistor, Chip, 1/16W

603

Std

Std

 

 

 

 

 

 

R4

Resistor, Chip, 1/2W

2010

CRCW20100000Z0EF

Vishay

 

 

 

 

 

 

R7

475kΩ

Resistor, Chip, 1/16W, 1%

603

Std

Std

 

 

 

 

 

 

R8

46.4kΩ

Resistor, Chip, 1/16W, 1%

603

Std

Std

 

 

 

 

 

 

R9

453Ω

Resistor, Chip, 1/16W, 1%

603

Std

Std

 

 

 

 

 

 

R10

187Ω

Resistor, Chip, 1/10W, 1%

603

Std

Std

 

 

 

 

 

 

R11

75.0kΩ

Resistor, Chip, 1/16W, 1%

603

Std

Std

 

 

 

 

 

 

R12

16.9kΩ

Resistor, Chip, 1/16W, 1%

603

Std

Std

 

 

 

 

 

 

R16

10.0kΩ

Resistor, Chip, 1/16W, 1%

603

Std

Std

 

 

 

 

 

 

U1

BQ24450D

IC, INTEGRATED CHARGE

SO-16

BQ24450D

TI

 

 

CONTROLLER

 

 

 

 

 

FOR LEAD-ACIDBATTERIES

 

 

 

 

 

 

 

 

 

SLUU464–November2010

bq24450EVM

7

Submit Documentation Feedback

 

 

© 2010, Texas Instruments Incorporated

Bill of Materials, Board Layouts and Schematic

www.ti.com

7.2Board Layout

Figure 4. Top Assembly Layer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 5. Top PCB Layer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8

bq24450EVM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SLUU464–November2010

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Submit Documentation Feedback

© 2010, Texas Instruments Incorporated

www.ti.com

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bill of Materials, Board Layouts and Schematic

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6. Bottom PCB Layer

7.3Schematic

Figure 7. bq24450 EVM Schematic

SLUU464–November2010

bq24450EVM

9

Submit Documentation Feedback

 

 

© 2010, Texas Instruments Incorporated

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 ONLYand 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. As such, the goods being provided are not intended to be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product safety and environmental measures typically found in end products that incorporate such semiconductor components or circuit boards. This evaluation board/kit does not fall within the scope of the European Union directives regarding electromagnetic compatibility, restricted substances (RoHS), recycling (WEEE), FCC, CE or UL, and therefore may not meet the technical requirements of these directives or other related directives.

Should this evaluation board/kit not meet the specifications indicated in the User’s Guide, the board/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 STATUTORY, 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. 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 User’s Guide and, specifically, the Warnings and Restrictions notice in the User’s Guide prior to handling the product. 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 or services might be or are used.

FCC Warning

This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLYand is not considered by TI to be a finished end-product fit for general consumer use. It generates, uses, and can radiate radio frequency energy and has not been tested for compliance with the limits of computing devices pursuant to part 15 of FCC rules, which are designed to provide reasonable protection against radio frequency interference. Operation of this equipment in other environments may cause interference with radio communications, in which case the user at his own expense will be required to take whatever measures may be required to correct this interference.

EVM Warnings and Restrictions

It is important to operate this EVM within the input voltage range of 9.5 V to 10.5 V and the output voltage range of 4 V to 7.5 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 75° C. The EVM is designed to operate properly with certain components above 75° 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

Copyright © 2010, Texas Instruments Incorporated