MCP3421DM-BFG - Microchip Technology

MCP3421

Battery Fuel Gauge

Demo Board

User’s Guide

Information contained in this publication regarding device

applications and the like is provided only for your convenience

and may be superseded by updates. It is your responsibility to

ensure that your application meets with your specifications.

MICROCHIP MAKES NO REPRESENTATIONS OR

WARRANTIES OF ANY KIND WHETHER EXPRESS OR

IMPLIED, WRITTEN OR ORAL, STATUTORY OR

OTHERWISE, RELATED TO THE INFORMATION,

INCLUDING BUT NOT LIMITED TO ITS CONDITION,

QUALITY, PERFORMANCE, MERCHANTABILITY OR

FITNESS FOR PURPOSE. Microchip disclaims all liability

arising from this information and its use. Use of Microchip

devices in life support and/or safety applications is entirely at

the buyer’s risk, and the buyer agrees to defend, indemnify

and hold harmless Microchip from any and all damages,

claims, suits, or expenses resulting from such use. No

licenses are conveyed, implicitly or otherwise, under any

Microchip intellectual property rights.

Trademarks

The Microchip name and logo, the Microchip logo, Accuron,

dsPIC, KEELOQ, KEELOQ logo, microID, MPLAB, PIC, PICmi-

cro, PICSTART, PRO MATE, rfPIC and SmartShunt are regis-

tered trademarks of Microchip Technology Incorporated in the

U.S.A. and other countries.

AmpLab, FilterLab, Linear Active Thermistor, Migratable

Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The

Embedded Control Solutions Company are registered trade-

marks of Microchip Technology Incorporated in the U.S.A.

Analog-for-the-Digital Age, Application Maestro, CodeGuard,

dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,

ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Cir-

cuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM,

MPLAB Certified logo, MPLIB, MPLINK, PICkit, PICDEM,

PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, Power-

Mate, PowerTool, REAL ICE, rfLAB, Select Mode, Smart

Serial, SmartTel, Total Endurance, UNI/O, WiperLock and

ZENA are trademarks of Microchip Technology Incorporated

in the U.S.A. and other countries.

SQTP is a service mark of Microchip Technology Incorporated

in the U.S.A.

All other trademarks mentioned herein are property of their

respective companies.

Printed on recycled paper.

Note the following details of the code protection feature on Microchip devices:

• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the

intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our

knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data

Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not

mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our

products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts

allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Microchip received ISO/TS-16949:2002 certification for its worldwide

headquarters, design and wafer fabrication facilities in Chandler and

Tempe, Arizona; Gresham, Oregon and design centers in California

and India. The Company’s quality system processes and procedures

are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping

devices, Serial EEPROMs, microperipherals, nonvolatile memory and

analog products. In addition, Microchip’s quality system for the design

and manufacture of development systems is ISO 9001:2000 certified.

MCP3421 BATTERY FUEL GAUGE

DEMO BOARD USER’S GUIDE

Table of Contents

Preface ........................................................................................................................... 1

Chapter 1. Product Overview

1.1 Introduction ..................................................................................................... 5

1.2 Features ......................................................................................................... 6

Chapter 2. Installation and Operation

2.1 Board Description ........................................................................................... 9

2.2 Getting Started ............................................................................................. 11

Appendix A. Schematic and Layouts

A.1 Introduction .................................................................................................. 15

A.2 Schematic .................................................................................................... 16

A.3 Top Layer and Silk Screen ......................................................................... 17

A.4 Bottom Layer ............................................................................................. 17

Appendix B. Bill Of Materials (BOM)

Worldwide Sales and Service .................................................................................... 22

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

NOTES:

MCP3421 BATTERY FUEL GAUGE

DEMO BOARD USER’S GUIDE

Preface

INTRODUCTION

This chapter contains general information that will be useful to know before using the

MCP3421 Battery Fuel Gauge Demo Board. Items discussed in this chapter include:

• Document Layout

• Conventions Used in this Guide

• Recommended Reading

• The Microchip Web Site

• Customer Support

• Document Revision History

DOCUMENT LAYOUT

This document describes how to use the MCP3421 Battery Fuel Gauge Demo Board

as a development tool. The manual layout is as follows:

•Chapter 1. “Product Overview” - Provides the important information about the

MCP3421 Battery Fuel Gauge Demo Board.

•Chapter 2. “Installation and Operation” – Covers the installation and operation

of the MCP3421 Battery Fuel Gauge Demo Board. It lists the required tools,

shows how to set up the board, and demonstrates how to verify the amplifier

operation.

•Appendix A. “Schematic and Layouts” – Shows the schematic and board

layouts for the MCP3421 Battery Fuel Gauge Demo Board.

•Appendix B. “Bill Of Materials (BOM)” – Lists the parts used to build the

MCP3421 Battery Fuel Gauge Demo Board.

NOTICE TO CUSTOMERS

All documentation becomes dated, and this manual is no exception. Microchip tools and

documentation are constantly evolving to meet customer needs, so some actual dialogs

and/or tool descriptions may differ from those in this document. Please refer to our web site

(www.microchip.com) to obtain the latest documentation available.

Documents are identified with a “DS” number. This number is located on the bottom of each

page, in front of the page number. The numbering convention for the DS number is

“DSXXXXXA”, where “XXXXX” is the document number and “A” is the revision level of the

document.

For the most up-to-date information on development tools, see the MPLAB® IDE on-line help.

Select the Help menu, and then Topics to open a list of available on-line help files.

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

CONVENTIONS USED IN THIS GUIDE

This manual uses the following documentation conventions:

DOCUMENTATION CONVENTIONS

Description Represents Examples

Arial font:

Italic characters Referenced books MPLAB® IDE User’s Guide

Emphasized text ...is the only compiler...

Initial caps A window the Output window

A dialog the Settings dialog

A menu selection select Enable Programmer

Quotes A field name in a window or

dialog

“Save project before build”

Underlined, italic text with

right angle bracket

A menu path File>Save

Bold characters A dialog button Click OK

A tab Click the Power tab

N‘Rnnnn A number in verilog format,

where N is the total number of

digits, R is the radix and n is a

digit.

4‘b0010, 2‘hF1

Text in angle brackets < > A key on the keyboard Press <Enter>, <F1>

Courier New font:

Plain Courier New Sample source code #define START

Filenames autoexec.bat

File paths c:\mcc18\h

Keywords _asm, _endasm, static

Command-line options -Opa+, -Opa-

Bit values 0, 1

Constants 0xFF, ‘A’

Italic Courier New A variable argument file.o, where file can be

any valid filename

Square brackets [ ] Optional arguments mcc18 [options] file

[options]

Curly brackets and pipe

character: { | }

Choice of mutually exclusive

arguments; an OR selection

errorlevel {0|1}

Ellipses... Replaces repeated text var_name [,

var_name...]

Represents code supplied by

user

void main (void)

{ ...

}

Preface

RECOMMENDED READING

This user's guide describes how to use MCP3421 Battery Fuel Gauge Demo Board.

Other useful documents are listed below. The following Microchip documents are

available and recommended as supplemental reference resources.

MPLAB® IDE, Simulator, Editor User's Guide (DS51025)

Consult this document for more information pertaining to the installation and features of

the MPLAB Integrated Development (IDE) Software.

MCP3421 Data Sheet, “18-Bit ADC with I2C Interface and On-Board Reference“

(DS22003)

Data sheet for the 18 bit ADC MCP3421. This data sheet is needed to understand how

the MCP3421 is used to meaure the current and battery voltage.

MCP73831/2 Data Sheet, “Miniature Single-Cell, Fully Integrated Li-Ion, Li-Poly-

mer Charge Management Controllers“ (DS21984)

Data sheet for the Single-Cell Li-Ion, LI-Polymer Charger. This data sheet is helpful to

understand how the battery fuel is charged.

PIC18F2455/2550/4455/4550 Data Sheet, (DS39632)

This data sheet is needed if the user wants to modify the firmware used in the demo

board.

THE MICROCHIP WEB SITE

Microchip provides online support via our web site at www.microchip.com. This web

site is used as a means to make files and information easily available to customers.

Accessible by using your favorite Internet browser, the web site contains the following

information:

•Product Support – Data sheets and errata, application notes and sample

programs, design resources, user’s guides and hardware support documents,

latest software releases and archived software

•General Technical Support – Frequently Asked Questions (FAQs), technical

support requests, online discussion groups, Microchip consultant program

member listing

•Business of Microchip – Product selector and ordering guides, latest Microchip

press releases, listing of seminars and events, listings of Microchip sales offices,

distributors and factory representatives

CUSTOMER SUPPORT

Users of Microchip products can receive assistance through several channels:

• Distributor or Representative

• Local Sales Office

• Field Application Engineer (FAE)

• Technical Support

Customers should contact their distributor, representative or field application engineer

for support. Local sales offices are also available to help customers. A listing of sales

offices and locations is included in the back of this document.

Technical support is available through the web site at: http://support.microchip.com

Note: In the MCP3421 Battery Fuel Gauge Demo Board Kit, the battery charging

function is disabled. Contact Microchip Technology, Inc., if you need this

function enabled.

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

DOCUMENT REVISION HISTORY

Revision A (October 2007)

• Initial Release of this Document.

MCP3421 BATTERY FUEL GAUGE

DEMO BOARD USER’S GUIDE

Chapter 1. Product Overview

1.1 INTRODUCTION

The MCP3421 Battery Fuel Gauge Demo Board is used to demonstrate the MCP3421

device for battery fuel gauging applications.

The MCP3421 Battery Fuel Gauge Demo Board includes two MCP3421 devices,

MCP73831(single cell Li-Ion/Li-Polymer Charger), and PIC18F4550 MCU.

The MCP3421 device is a low-power, single channel 18-bit delta-sigma Analog-to-Dig-

ital Converter (ADC) in a SOT-23 package. It has an internal voltage reference

(VREF = 2.048V) and programmable gain amplifier (x1,x2, x4, x8). It communicates

with a master device with I2C interface.

The MCP3421 Battery Fuel Gauge Demo Board measures: (a) the battery voltage and

(b) the current coming out from the battery in the discharging mode and into the battery

in the charging mode using the ADC device (if charging mode is enabled (optional)). It

calculates the total fuel used and also remaining fuels. The measurement takes places

approximately every one second and updates the measurement data and calculated

results on the LCD for about every second.

The MCP3421 Battery Fuel Gauge Demo Board includes 2x16 LCD. The LCD

displays: (a) measured battery voltage and current, (b) calculated results of battery fuel

used.

The MCP3421 Battery Fuel Gauge Demo Board also includes a buzzer. This buzzer

makes a buzzing sound when the battery voltage drops 50% or the battery is not

connected.

The PIC18F4550 communicates with the MCP3421 and calculates the fuels. The

board also includes a USB connector for a PC graphic user interface (GUI) utility. This

GUI is available only for the training class and not included with this demo kit.

Figure 1-1 shows the picture of the MCP3421 Battery Fuel Gauge Demo Board. The

board includes device foot prints for the two channel 18-bit ADC (MCP3422). The

MCP3421 and MCP3422 are the same device family with the same electrical

performance, but the MCP3422 has two channels. Therefore, the two MCP3421

devices on the board can be replaced with one MCP3422 device.

Note: MCP3421 Battery Fuel Gauge Demo Board has a feature to charge the

battery in use. This feature is currently disabled in firmware. Please contact

Microchip Technology Inc. if you need the battery charging feature.

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

1.2 FEATURES

The MCP3421 Battery Fuel Gauge Demo Board has the following features:

• Measure the battery voltage and display the result on LCD.

• Measure the current coming out from the battery (discharging current) or coming

into the battery (charging current) and displays the value on LCD.

• Calculate the battery fuel that has been used and display the result on LCD.

• Turn on beep sounds if the battery is used more than 50% of its initial value, or the

battery is not connected.

The MCP3421 Battery Fuel Gauge Demo Board includes a 9V and 1.5V AAA batteries.

Please make sure the positive lead of the 1.5V battery holder is connected to TP9 and

the negative lead (black) is connected to the GND terminal.

Note: The charging current is only available when the battery charging mode is

enabled.

Note: The MCP3421 Battery Fuel Gauge Demo Board can be also configured

very easily for other sensor output measurements. Just connect the sensor

output at the ADC input terminal. The LCD will display the voltage.

WARNING

The U1 and U5 devices may get damaged if the polarity of the battery connection is

reversed. If the connection is accidently reversed, replace the U1 and U5 devices in

order to obtain accurate measurements.

Product Overview

FIGURE 1-1: MCP3421 Battery Fuel Gauge Demo Board (Top Side).

9V Power Supply

MCP3421 I2C

Interface Test Points

(See Note 1)

Test Pins for Battery Charger

Menu Selection Switch

Connector for

MPLAB® ICD2 In-Circuit

2x16 LCD

MCP3421

MCP3422

Footprint MCP73831

MCU MCLR Reset Switch

Potentiometer

USB

Jumper for Discharging Path

NOTICE

Note 1: Use 9V Power Supply or 9V Battery. Do not use both at same time.

2: 1.5V battery connection: connect the positive lead (red) to TP9 and the negative lead

(black) to the GND terminal. A reversed connection will damage the U1 and U5 devices.

1.5V Battery

Connector

(not used)

–

Red Lead

Black Lead

1.5V AAA

Battery

Insertion of 1.5V AAA Battery

into Battery Holder

9V Battery

(See Note 1)

Connector (TP11)

Current

Sensor

PIC18F4550

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

FIGURE 1-2: MCP3421 Battery Fuel Gauge Demo Board (Bottom Side).

Buzzer

MCP3421 BATTERY FUEL GAUGE

DEMO BOARD USER’S GUIDE

Chapter 2. Installation and Operation

2.1 BOARD DESCRIPTION

The major components of the MCP3421 Battery Fuel Gauge Demo Board are:

1. MCP3421 devices (U1 and U5).

- U1: Measuring current using the R12 current sensor.

- U5: Measuring battery voltage.

2. PIC MCU - PCI18F4550 (U2).

3. MPLAB ICD2 Header (P2).

4. USB connector (Not used for this version).

5. Battery discharging path selection Jumper (JP1).

6. Battery charging path selection Jumper (JP2): When battery recharge feature is

enabled.

7. 9V Power Supply (BAT 1 and 9V power supply, use only one).

8. 1.5V AAA Battery with battery holder.

9. 2 x 16 LCD (LCD1).

10. MCP73831 device (U3).

11. Switches (SW1, SW2, SW3, SW4, Reset Switch).

12. Potentiometer (R1).

For more detailed circuit information, refer to Appendix A: “Schematics and Layouts”

and Appendix B: Bill of Materials”.

2.1.1 Power Supply

The MCP3421 Battery Fuel Gauge Demo Board needs a 9V power supply to provide

a 5V DC power to all active components including MCU, ADC, battery charger devices,

etc. The user can use a 9V power supply or 9V battery. The MCP3421 Battery Fuel

Gauge Demo Board has two connectors for both the 9V power supply and 9V battery.

Do not use both power sources at same time.

2.1.2 Microcontroller (MCU)

The PIC18F4550 (44-pin, TQFT) is used to control ADC devices, charger, buzzer, and

LCD. All fuel gauge computations are takes place in the MCU.

2.1.3 LCD Display

The LCD display used is a 2 x 16 character dot matrix type display. The PIC18F4550

device writes characters to the LCD.

Note: All active electrical components on the board are powered by the 9V power

source. The 1.5V AAA battery that is connected to TP9 (positive) and GND

(negative) terminals DOES NOT power the board components. During the

discharging, the current path of the test battery is from the 1.5V battery to

the ground via a 10 mili-ohm current sensor and an 100Ω resistor. During

the recharging mode (if recharging mode is enabled), the current path is

from the VBAT pin of U3 (MCP73831) to the battery via the current sensor.

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

2.1.4 Buzzer

This demo board has a buzzer. The buzzer beeps when the board is first powered up

and also when the battery fuel is consumed 50% or less, or the battery is disconnected.

2.1.5 USB Connector

This board has a USB connector for the PIC18F4550. The current firmware version for

the PIC18F4550 is not including the USB interface feature.

2.1.6 Interface to MPLAB® ICD2 Programmer

The MCP3421 Battery Fuel Gauge Demo Board includes the PIC18F4550. This MCU

is used to control the data acquisition devices (ADC) and compute the fuel gauging

parameters. The MCU also sends characters to the LCD.

The board has an 8-pin connector for the ICD In-Circuit Serial Programming™

(ICSP™). The MCU source code is written in assembly language. The user can modify

the code for their own experiment using the MPLAB ICD2 Programmer. The user needs

an ICD-2 ICSP adapter socket (P/N: AC164110) between the MPLAB ICD2 Program-

mer and the MCP3421 Battery Fuel Gauge Demo Board.

2.1.7 Jumper

The MCP3421 Battery Fuel Gauge Demo Board uses two jumpers, JP1 and JP2. JP1

is used to provide a battery discharge path. Connect JP1 (while JP2 is disconnected)

when testing battery discharging. Contact Microchip Technology Inc., if you need the

battery charging mode.

2.1.8 Push Button Switches

The MCP3421 Battery Fuel Gauge Demo Board has 5 push button switches.

•SW1 is used to enter the battery fuel gauging mode.

•SW2, SW3, SW4: are not Used.

•Reset SW is the MCLR reset pin switch and is used to reset the MCU.

2.1.9 Potentiometer (R1)

This potentiometer is used to calibrate the input voltage to the ADC and is calibrated

before shipping to the customer. If the customer wants to calibrate, then refer to Step 5

of the calibration procedure in Section 2.2.1 “Battery Fuel Measurement”.

2.1.10 Signal Outputs

The MCP3421 Battery Fuel Gauge Demo Board has various test points to capture the

communication between the MCU and ADC devices. The user can see the I2C

communication data streams at SCL and SDA test pins using an oscilloscope. The

SYNC terminal is used as a “trigger” source when the SCL and SDA signals are

captured. The board also has the test terminals for the battery charger (U3): Prog 1,

Prog 2 and C-STAT terminals.

Note: Do not connect both JP1 and JP2 at the same time.

Installation and Operation

2.2 GETTING STARTED

You can simulate battery voltage discharging and charging using the MCP3421 Battery

Fuel Gauge Demo Board.

Battery Fuel Measurement Mode: The MCP3421 Battery Fuel Gauge Demo Board

measures the currents coming from the battery every second and computes how many

fuels are being used. The fuel is calculated from the time when the MCP3421 Battery

Fuel Gauge Demo Board is powered and the fuel measurement is initiated. When JP1

jumper is connected, a battery discharging path from the battery to the current sensor

to the 100Ω resistor (R11) to ground is created. This simulates how battery fuel is

consumed in real applications. The differential input pins of U1 (ADC) are connected

across the current sensor and measure the current passing through the current sensor.

The ADC can determine whether the measured current is discharging current or charg-

ing current by testing the sign of the current value. In the battery discharging path, the

direction of current flow is from the battery to the ground through R12 and R11. There-

fore, the LCD will display a positive sign (‘ + ‘) on the display.

2.2.1 Battery Fuel Measurement

The battery fuel being used is measured by setting up a discharge path. This discharge

path is created when connecting Jumper 1 (JP1) while disconnecting Jumper 2 (JP2).

1. Connect JP1.

2. Connect a 9V power supply to J1, or connect a 9V battery to TP11.

There are two 9V connections. You can use either 9V battery or 9V power supply. Only

one power source is used.

3. The LED D3 will turn on, and the LCD will display the following message:

4. A few seconds later, the LCD will display the following message:

5. Press S1. The LCD will display the following message:

If the 1.5V battery is disconnected, connect the positive lead (red) of the 1.5V

battery holder to the TP9 terminal and the negative lead (black) to the GND ter-

minal. Make sure the 1.5V AAA battery is correctly inserted into the battery

holder. Press the S1 push button.

Note: Make sure JP2 is not connected.

Microchip

Fuel Gauge Demo

ConntJP1, Push S1

Disconnect JP2

Connect 1.5V Bat

at TP9. Press S1

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

6. The LCD will display the following message continuously:

If this happens, one of the symptoms is that the LCD will display a higher reading or a

lesser reading (negative) sign in the current “I” reading. Please replace the U1 and U5

devices, if this incident occurred or contact Microchip Technology Inc.

V = +1.5203062 V

I = +0.0141780 A

Fuel Used:

0.02452 mAh

WARNING

If the 1.5V AAA battery is reverse connected to the TP9 and GND, it will cause

permanent damage to the U1 and U5 devices. The reading on the LCD is not reliable

anymore.

Installation and Operation

ADC Input Voltage Calibration:

The potentiometer (R1) is used to calibrate the ADC input voltage. If the displayed bat-

tery voltage on the LCD is suspicious, the customer can calibrate the ADC input voltage

using the following method:

1. Connect a digital voltmeter between the TP9 (Battery) and Ground (TP4).

2. Read the volts value on the LCD while adjusting the potentiometer. Adjust the

potentiometer until the reading on the LCD is the same as the reading on the

Digital Volt Meter (DVM). This completes the ADC input calibration.

FIGURE 2-1: MCP3421 Battery Fuel Gauge Computation Algorithm.

Note: The MCP3421 (U5) is used to measure the battery voltage. The internal

reference voltage of the MCP3421 is 2.048V. The MCP3421 (U5) will give

a saturated output if the input is greater than its reference voltage (2.048V).

To avoid the saturation, the MCP3421 Battery Fuel Gauge Demo Board

uses a voltage divider formed by R3, R4 and R1. The potentiometer (R1) is

used to calibrate the voltage divider, and provide 50% of the voltage applied

at TP9 to the input pin of the MCP3421 (U5).

The microcontroller (U2) firmware takes into account this voltage divider

value automaticaly. The firmware multiplies a factor of 2 on the U5 result

and displays the result on the LCD.

Get ADC value from U1

( for Battery Voltage)

Battery Volt = 2 * Acquired Volts

(ADC Input = Voltage after voltage divider)

Get ADC value from U5

( for Discharging Current)

Battery Volts < 50% ?

* Discharging Fuel (mAh) = Discharging Current (mAs)/3600

Beep

Display Battery Volts and

Discharging Current

Display Fuel Used

Yes

START

Fuel Used (mAh) = Discharging Fuel (mAh)

i0=

∑

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

FIGURE 2-2: MCP3421 Battery Fuel Gauge Computation Algorithm with Battery Recharge Feature

Enabled. (Contact Microchip Technology Inc., if you need this feature enabled).

Get ADC value from U1

( for Battery Voltage)

Battery Volt = 2 * Acquired Volts

(ADC Input = Voltage after voltage divider)

Get ADC value from U5

( for Discharging Current)

Battery Volts < 50% ?

* Discharging Fuel (mAh) = Discharging Current (mAs)/3600

Fuel Remain (mAh) = Fuel Remain (mAh)

+ Fuel Charged (mAh)

Fuel Remain (mAh) = Initial Battery Fuel = 170 mAh, 4.2V

Is Battery Fully Charged ?

Interrupted ?

Get ADC value from U1

( for Charging Current)

Get ADC value from U5

(Battery Volts)

Display Charging Current &

Battery Volts

Display Battery Volts and

Discharging Current

Display Fuel Remain &

Fuel Used

Yes

START

Fuel Used (mAh) = Discharging Fuel (mAh)

i0=

∑

Yes

Want

Recharge Battery?

MCP3421 BATTERY FUEL GAUGE

DEMO BOARD USER’S GUIDE

Appendix A. Schematic and Layouts

A.1 INTRODUCTION

This appendix contains the schematics and PCB layouts for the MCP3421 Battery Fuel

Gauge Demo Board. This Appendix includes:

• Schematic

• Top Layer (with silk screen)

• Bottom Layer

NOTICE TO CUSTOMERS

All documentation becomes dated, and this user’s guide is no exception. Microchip tools and

documentation are constantly evolving to meet customer needs, so some schematics and

board layouts may differ from those in this document. Please refer to our web site

(www.microchip.com) to obtain the latest documentation available.

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

A.2 SCHEMATIC

Schematic and Layouts

A.3 TOP LAYER AND SILK SCREEN

A.4 BOTTOM LAYER

BOARD EDGE

MCP3421 Battery Fuel Gauge Demo Board User’s Guide

NOTES:

MCP3421 BATTERY FUEL GAUGE

DEMO BOARD USER’S GUIDE

Appendix B. Bill Of Materials (BOM)

NOTICE TO CUSTOMERS

All documentation becomes dated, and this user’s guide is no exception. Microchip tools and

documentation are constantly evolving to meet customer needs, so the Bill Of Materials may

differ from those in this document. Please refer to our web site (www.microchip.com) to

obtain the latest documentation available.

TABLE B-1: BILL OF MATERIALS (BOM)

Qty Reference Description Manufacturer Part Number

1 BAT1 BATTERY ALKALINE 9V Gold Peak 29A

1 BAT1 + lug CONN BATT 9V MALE OFF-BRD

SNAP

Keystone Electronics®635

1 BAT1 - lug CONN BATT 9V FEMALE

OFF-BRD SNAP

Keystone Electronics 636

0 BAT2 DO NOT POPULATE

Polymer Li-Ion Battery: One Mini

size (25x20x5 mm) 3.7V, 170mAh

for Micro RC Car or Device

— PL-052025

1 BAT3 IC Test Clips Red Kobiconn 13IC307

1 BAT3 IC Test Clips Black Kobiconn 13IC308

1 BAT3 HOLDER BATTERY 1CELL AAA

6"LEAD

Keystone Electronics 2467

1 BT3 Alkaline Batteries AAA SIZE ALKA-

CELL

Gold Peak GP24AU-OS2

1 BUZZER PIEZO BUZZER PIEZO 4KHZ 17.5MM

SMT

Mallory Sonalert

Products Inc

AST100Q

9 C1, C4, C7, C9,

C10, C11, C12,

C13, C19

CAP .1UF 16V CERAMIC

X7R 0603

Panasonic® - ECG ECJ-1VB1C104K

2 C2, C3 CAP CERAMIC 4.7UF 6.3V

X5R 0603

Panasonic - ECG ECJ-1VB0J475K

3 C5, C17, C18 CAP 1.0UF 16V CERAMIC

X5R 0603

Panasonic - ECG ECJ-1VB1C105K

1 C6 CAP CER .33UF 16V X7R 0603 Murata Electronics North

America

GRM188R71C334KA01D

2 C8,C14 CAP CER 10UF 6.3V X5R 0603 Murata Electronics North

America

GRM188R60J106ME47D

2 C15, C16, CAP CERAMIC 18PF 50V

0603 SMD

Panasonic - ECG ECJ-1VC1H180J

1 D1 LED THIN 565NM GRN DIFF

0805 SMD

Lumex® Inc. SML-LXT0805GW-TR

Note: The components listed in this Bill of Materials are representative of the PCB assembly. The

released BOM used in manufacturing uses all RoHS-compliant components.

Bill Of Materials (BOM)

10 D2, D6, D7, D8,

D9, D10, D11,

D12, D13, D14

LED THIN 635NM RED DIFF

0805 SMD

Lumex Inc. SML-LXT0805IW-TR

1 D3 Lumex Opto/Components Inc Lumex Inc. SML-LX15IC-TR

1 D4 DIODE SWITCH 100V 150MA

SOD123

Micro Commercial Co. 1N4148W-TP

1 D5 DIODE SWITCHING 100V DO35 Micro Commercial Co. 1N914B-TP

4 Ea. Corner SCREW MACH PHIL 4-40X1/4

NYLON

Building Fasteners NY PMS 440 0025 PH

4 Ea. Corner STANDOFF HEX .375/4-40THR

NYLON

Keystone Electronics 1902B

1 J1 CONN POWER JACK 2.5MM PCB

CIRC

CUI Inc PJ-102B

2 JP1, JP2 CONN HEADER VERT 2POS .100

TIN

Tyco® Electronics/Amp 3-644695-2

0 JP3 Do Not Populate — —

2 SHNTS

JP1 & JP2

SHUNT LP W/HANDLE 2 POS

30AU

Tyco Electronics/Amp 881545-2

1 L1 INDUCTOR FIXED SMD 10UH

10%

Panasonic - ECG ELJ-FC100KF

1 LCD1 16 X 2 LCD Character Display Fema CG1626-SGR1

0 P2 Do Not Populate Tyco Electronics/Amp 3-644456-6

1 PCB RoHS Compliant Bare PCB,

MCP3421 Battery Fuel Gauge

Demo Board

— 104-00121

1 R1 POT 200K OHM THUMBWHEEL

CERM ST

Bourns Inc. 3352T-1-204LF

7 R2, R7, R10,

R17, R18, R28,

R29

RES 10.0K OHM 1/10W 1%

0603 SMD

Vishay/Dale CRCW060310K0FKEA

1 R3 RES 510K OHM 1/10W 5%

0603 SMD

Rohm MCR03EZPJ514

1 R4 RES 390K OHM 1/10W 5%

0603 SMD

Rohm MCR03EZPJ394

1 R5 RES 100K OHM 1/10W 1%

0603 SMD

Vishay/Dale CRCW0603100KFKEA

1 R6 RES 2.49K OHM 1/10W 1%

0603 SMD

Vishay/Dale CRCW06032K49FKEA

2 R8, R9 RES 221 OHM 1/10W 1%

0603 SMD

Vishay/Dale CRCW0603221RFKEA

1 R11 RES 100 OHM 1/8W 1% 0805 SMD Panasonic - ECG ERJ-6ENF1000V

1 R12 RES CURRENT SENSE .010 OHM

Ohmite 13FR010E

9 R13, R14, R15,

R19, R26, R27,

R32, R33, R34

RES 1.5K OHM 1/16W .5%

0603 SMD

Susumu Co Ltd RR0816P-152-D

2 R16, R30, R31 RES 1.0K OHM 1/10W .5%

0603 SMD

Yageo® Corporation RT0603DRD071KL

TABLE B-1: BILL OF MATERIALS (BOM) (CONTINUED)

Qty Reference Description Manufacturer Part Number

Note: The components listed in this Bill of Materials are representative of the PCB assembly. The

released BOM used in manufacturing uses all RoHS-compliant components.

Bill Of Materials (BOM)

1 R20 RES 332 OHM 1/10W 1% 0603

SMD

Vishay/Dale CRCW0603332RFKEA

2 R21, R22 RES 24.9 OHM 1/10W 1% 0603

SMD

Vishay/Dale CRCW060324R9FKEA

0 R23 Do Not Populate — —

1 R24 RES 523 OHM 1/10W 1% 0603

SMD

Panasonic - ECG ERJ-3EKF5230V

1 R25 RES 4.7K OHM 1/10W 5% 0603

SMD

Panasonic - ECG ERJ-3GEYJ472V

2 R35, R36 RES 0.0 OHM 1/10W 5% 0603

SMD

Yageo Corporation RC0603JR-070RL

5 S1, S2, S3, S4,

SWITCH LT TOUCH 6X3.5

100GF SMD

Panasonic - ECG EVQ-PJS04K

12 TP1<>TP18 PC TEST POINT COMPACT SM Keystone Electronics 5016

1 U1 18-Bit Analog-to-Digital Converter

with I2C Interface and On-Board

Reference

Microchip Technology

Inc.

MCP3421A0T-E/OT

1 U2 High-Performance, Enhanced

Flash, USB Microcontroller, 44-Pin,

QFP

Microchip Technology

Inc.

PIC18F4550-I/PT

1 U3 Minature Single Cell, Fully inte-

grated Li-Ion, Li-Polymer Charge

Management Controller

Microchip Technology

Inc.

MCP73831-2ACI/OT

Alternate Part#

MCP73831-2ACI/OT

1 U4 MCP1702 mA Low Quiescent

Current LDO Regulator

Microchip Technology

Inc.

MCP1702T-5002I/CB

1 U5 18-Bit Analog-to-Digital Converter

with I2C Interface and On-Board

Reference

Microchip Technology

Inc.

MCP3421A3T-E/OT

0 U6 Do Not Populate — —

1 USB1 CONN RECEPT MINI USB2.0

5POS

Hirose Electronic Co. Ltd UX60-MB-5ST

1 X1 CRYSTAL 20.000MHZ 18PF FUND

SMD

Connor-Winfield XM-1-20.0000

TABLE B-1: BILL OF MATERIALS (BOM) (CONTINUED)

Qty Reference Description Manufacturer Part Number

Note: The components listed in this Bill of Materials are representative of the PCB assembly. The

released BOM used in manufacturing uses all RoHS-compliant components.

AMERICAS

Corporate Office

2355 West Chandler Blvd.

Chandler, AZ 85224-6199

Tel: 480-792-7200

Fax: 480-792-7277

Technical Support:

http://support.microchip.com

Web Address:

www.microchip.com

Atlanta

Duluth, GA

Tel: 678-957-9614

Fax: 678-957-1455

Boston

Westborough, MA

Tel: 774-760-0087

Fax: 774-760-0088

Chicago

Itasca, IL

Tel: 630-285-0071

Fax: 630-285-0075

Dallas

Addison, TX

Tel: 972-818-7423

Fax: 972-818-2924

Detroit

Farmington Hills, MI

Tel: 248-538-2250

Fax: 248-538-2260

Kokomo

Kokomo, IN

Tel: 765-864-8360

Fax: 765-864-8387

Los Angeles

Mission Viejo, CA

Tel: 949-462-9523

Fax: 949-462-9608

Santa Clara

Santa Clara, CA

Tel: 408-961-6444

Fax: 408-961-6445

Toronto

Mississauga, Ontario,

Canada

Tel: 905-673-0699

Fax: 905-673-6509

ASIA/PACIFIC

Asia Pacific Office

Suites 3707-14, 37th Floor

Tower 6, The Gateway

Harbour City, Kowloon

Hong Kong

Tel: 852-2401-1200

Fax: 852-2401-3431

Australia - Sydney

Tel: 61-2-9868-6733

Fax: 61-2-9868-6755

China - Beijing

Tel: 86-10-8528-2100

Fax: 86-10-8528-2104

China - Chengdu

Tel: 86-28-8665-5511

Fax: 86-28-8665-7889

China - Fuzhou

Tel: 86-591-8750-3506

Fax: 86-591-8750-3521

China - Hong Kong SAR

Tel: 852-2401-1200

Fax: 852-2401-3431

China - Nanjing

Tel: 86-25-8473-2460

Fax: 86-25-8473-2470

China - Qingdao

Tel: 86-532-8502-7355

Fax: 86-532-8502-7205

China - Shanghai

Tel: 86-21-5407-5533

Fax: 86-21-5407-5066

China - Shenyang

Tel: 86-24-2334-2829

Fax: 86-24-2334-2393

China - Shenzhen

Tel: 86-755-8203-2660

Fax: 86-755-8203-1760

China - Shunde

Tel: 86-757-2839-5507

Fax: 86-757-2839-5571

China - Wuhan

Tel: 86-27-5980-5300

Fax: 86-27-5980-5118

China - Xian

Tel: 86-29-8833-7252

Fax: 86-29-8833-7256

ASIA/PACIFIC

India - Bangalore

Tel: 91-80-4182-8400

Fax: 91-80-4182-8422

India - New Delhi

Tel: 91-11-4160-8631

Fax: 91-11-4160-8632

India - Pune

Tel: 91-20-2566-1512

Fax: 91-20-2566-1513

Japan - Yokohama

Tel: 81-45-471- 6166

Fax: 81-45-471-6122

Korea - Daegu

Tel: 82-53-744-4301

Fax: 82-53-744-4302

Korea - Seoul

Tel: 82-2-554-7200

Fax: 82-2-558-5932 or

82-2-558-5934

Malaysia - Kuala Lumpur

Tel: 60-3-6201-9857

Fax: 60-3-6201-9859

Malaysia - Penang

Tel: 60-4-227-8870

Fax: 60-4-227-4068

Philippines - Manila

Tel: 63-2-634-9065

Fax: 63-2-634-9069

Singapore

Tel: 65-6334-8870

Fax: 65-6334-8850

Taiwan - Hsin Chu

Tel: 886-3-572-9526

Fax: 886-3-572-6459

Taiwan - Kaohsiung

Tel: 886-7-536-4818

Fax: 886-7-536-4803

Taiwan - Taipei

Tel: 886-2-2500-6610

Fax: 886-2-2508-0102

Thailand - Bangkok

Tel: 66-2-694-1351

Fax: 66-2-694-1350

EUROPE

Austria - Wels

Tel: 43-7242-2244-39

Fax: 43-7242-2244-393

Denmark - Copenhagen

Tel: 45-4450-2828

Fax: 45-4485-2829

France - Paris

Tel: 33-1-69-53-63-20

Fax: 33-1-69-30-90-79

Germany - Munich

Tel: 49-89-627-144-0

Fax: 49-89-627-144-44

Italy - Milan

Tel: 39-0331-742611

Fax: 39-0331-466781

Netherlands - Drunen

Tel: 31-416-690399

Fax: 31-416-690340

Spain - Madrid

Tel: 34-91-708-08-90

Fax: 34-91-708-08-91

UK - Wokingham

Tel: 44-118-921-5869

Fax: 44-118-921-5820

WORLDWIDE SALES AND SERVICE

10/05/07