Microchip Technology MCP1631 Guide

©2007 Microchip Technology Inc. DS51697A
MCP1631
Multi-Chemistry
Battery Charger
Reference Design

DS51697A-page ii ©2007 Microchip Technology Inc.
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and may be superseded by updates.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.
© 2007, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
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.

©2007 Microchip Technology Inc. DS51697A-page iii
MCP1631 MULTI-CHEMISTRY
BATTERY CHARGER
REFERENCE DESIGN
Table of Contents
Preface ...........................................................................................................................1
Introduction............................................................................................................ 1
Document Layout.................................................................................................. 1
Conventions Used in this Guide............................................................................ 2
Recommended Reading........................................................................................ 3
The Microchip Web Site........................................................................................3
Customer Support................................................................................................. 3
Document Revision History...................................................................................3
Chapter 1. Product Overview
1.1 Introduction .....................................................................................................5
1.2 What is the MCP1631 Multi-Chemistry Battery Charger
Reference Design? ................................................................................... 6
1.3 What the MCP1631 Multi-Chemistry Battery Charger
Reference Design Kit includes ................................................................. 6
Chapter 2. Installation and Operation
2.1 Introduction .....................................................................................................7
2.2 Features .........................................................................................................7
2.3 Getting Started ...............................................................................................8
Appendix A. Schematic and Layouts
A.1 Introduction ..................................................................................................13
A.2 Board – Schematic ....................................................................................... 14
A.3 Board – Top Silk Layer ................................................................................15
A.4 Board – Top Metal Layer ............................................................................. 16
A.5 Board – Mid1 Metal Layer ............................................................................ 17
A.6 Board – Mid2 Metal Layer ............................................................................ 18
A.7 Board – Bottom Metal Layer ........................................................................ 19
Appendix B. Bill Of Materials (BOM)
Appendix C. Demo Board Firmware
C.1 Device Firmware Flowchart Page 1 ............................................................. 23
Worldwide Sales and Service ....................................................................................24

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page iv ©2007 Microchip Technology Inc.
NOTES:

MCP1631 MULTI-CHEMISTRY
BATTERY CHARGER
REFERENCE DESIGN
©2007 Microchip Technology Inc. DS51697A-page 1
Preface
INTRODUCTION
This chapter contains general information that will be useful to know before using the
MCP1631 Multi-Chemistry Battery Charger Reference Design. 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 MCP1631 Multi-Chemistry Battery Charger
Reference Design. The manual layout is as follows:
•Chapter 1. “Product Overview” – Important information about the MCP1631
Multi-Chemistry Battery Charger Reference Design.
•Chapter 2. “Installation and Operation” – Includes instructions on how to get
started with this user’s guide and a description of the user’s guide.
•Appendix A. “Schematic and Layouts” – Shows the schematic and layout
diagrams for the MCP1631 Multi-Chemistry Battery Charger Reference Design.
•Appendix B. “Bill Of Materials (BOM)” – Lists the parts used to build the
MCP1631 Multi-Chemistry Battery Charger Reference Design.
•Appendix C. “Demo Board Firmware” – Provides information about the applica-
tion firmware and where the source code can be found.
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.

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 2 ©2007 Microchip Technology Inc.
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
©2007 Microchip Technology Inc. DS51697A-page 3
RECOMMENDED READING
This user's guide describes how to use MCP1631 Multi-Chemistry Battery Charger
Reference Design. The following Microchip documents are available and
recommended as supplemental reference resources.
MCP1631 Data Sheet, “High-Speed, Microcontroller-Adaptable, Pulse Width
Modulator”, DS22063
This data sheet provides detailed information regarding the MCP1631/MCP1631V,
MCP1631HV and MCP1631VHV product family.
PIC16F883 Data Sheet, "8-Pin Flash-Based, 8-Bit CMOS Microcontrollers with
Nano Watt Technology”, DS41291
This data sheet provides detailed information regarding the PIC16F883 product family.
AN1137 Application Note, “Using the MCP1631 Family to Develop Low-Cost Bat-
tery Chargers”, DS01137
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
(FAE) 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
DOCUMENT REVISION HISTORY
Revision A (January 2008)
• Initial Release of this Document.

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 4 ©2007 Microchip Technology Inc.
NOTES:

MCP1631 MULTI-CHEMISTRY
BATTERY CHARGER
REFERENCE DESIGN
©2007 Microchip Technology Inc. DS51697A-page 5
Chapter 1. Product Overview
1.1 INTRODUCTION
The MCP1631HV Multi-Chemistry referecne design board is used to charge one, two,
three or four NiMH batteries or one or two cell Li-Ion batteries. The board uses the
MCP1631HV high speed analog PWM and PIC16F883 to generate the charge
algorithum for NiMH, NiCd or Li-Ion batteries.
The MCP1631 Multi-Chemistry Battery Charger Reference Design is used to evaluate
Microchip’s MCP1631HV in a SEPIC power converter application. As provided, the
MCP1631 Multi-Chemistry Battery Charger Reference Design is user programmable
using on board push buttons. The board can charge NiMH, NiCd or Li-Ion batteries.
TheMCP1631Multi-ChemistryBattery ChargerReference Designprovides aconstant
current charge (Ni based chemistry) and constant current / constant voltage (Li-Ion)
with preconditioning, cell temperature monitoring (Ni based) and battery pack fault
monitoring. Also, the charger provides a status or fault indication. The MCP1631
Multi-Chemistry Battery Charger Reference Design automatically detects the insertion
or removal of a battery pack.
This chapter covers the following topics.
• What is the MCP1631 Multi-Chemistry Battery Charger Reference Design?
• What the MCP1631 Multi-Chemistry Battery Charger Reference Design Kit
includes.
FIGURE 1-1: MCP1631 Multi-Chemistry Battery Charger Reference Design
Block Diagram.
5.3V to 16V
Power Supply
MCP1631HV SEPIC
Battery Charger
+-
B+
B-
THERM
Multi-Chemistry

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 6 ©2007 Microchip Technology Inc.
1.2 WHAT IS THE MCP1631 MULTI-CHEMISTRY BATTERY CHARGER
REFERENCE DESIGN?
The MCP1631 Multi-Chemistry Battery Charger Reference Design is a complete
stand-alone constant current battery charger for NiMH, NiCd or Li-Ion battery packs.
When charging NiMH or NiCd batteries the reference design is capable of charging
one, two, three or four batteries connected in series. If Li-Ion chemistry is selected, the
board is capableof charging one or two series batteries. This board utilizes Microchip’s
MCP1631HV (high-speed PIC® MCU PWM TSSOP-20). The input voltage range for
the demo board is 5.3V to 16V.
TABLE 1-1: MULTI-CHEMISTRY CHARGER CAPABILITY
An input terminal block is provided to apply the input voltage to the charger. An output
header is also provided as a means to connect the external battery pack or simulated
battery load and external 10 kΩthermistor. A programming header is available for
updating the firmware contained in the PIC16F883.
1.3 WHAT THE MCP1631 MULTI-CHEMISTRY BATTERY CHARGER
REFERENCE DESIGN KIT INCLUDES
This MCP1631 Multi-Chemistry Battery Charger Reference Design kit includes:
• The MCP1631 Multi-Chemistry Battery Charger Reference Design Board,
102-00145
• Analog and Interface Products Demonstration Boards CD-ROM (DS21912)
- MCP1631 Multi-Chemistry Battery Charger Reference Design User’s Guide,
(DS51697).
- MCP1631 Data Sheet, “High-Speed, Microcontroller-Adaptable, Pulse Width
Modulator”, (DS22063).
- PIC16F883 Data Sheet, “8-Pin Flash-Based, 8-Bit CMOS Microcontrollers
with nanoWatt Technology”, (DS41291).
- AN1137, Using the MCP1631 Family to Develop Low-Cost Battery Chargers,
(DS01137)
Note: For this board, VIN must be greater than VOUT , duty cycle is limited to 50%.
This can be modified so that VOUT = VIN or VOUT > VIN becasue the SEPIC
converter is capable of buck-boost operation.
Battery Chemistry 1-Cell 2-Cell 3-Cell 4-Cell
Li-Ion 2A 1A N/A N/A
NiMH or NiCd 1.5A 1.5A 1.5A 1.5A

MCP1631 MULTI-CHEMISTRY
BATTERY CHARGER
REFERENCE DESIGN
©2007 Microchip Technology Inc. DS51697A-page 7
Chapter 2. Installation and Operation
2.1 INTRODUCTION
The MCP1631HV Multi-Chemistry Battery Charger demonstrates Microchip’s
high-speed Pulse Width Modulator (PWM), MCP1631HV, used in a multi-chemistry
battery charger application. When used in conjunction with a microcontroller, the
MCP1631HV will control the power system duty cycle to provide output voltage or
current regulation. The PIC16F883 microcontroller can be used to regulate output
voltageor setcurrent, switchingfrequency and maximumduty cycle. The MCP1631HV
generates duty cycle and provides fast overcurrent protection based off various
external inputs. External signals include the input oscillator, the reference voltage, the
feedbackvoltageand thecurrentsense. Theoutputsignal isa square-wavepulse. The
power train used for the MCP1631HV Multi-Chemistry Battery Charger is a
Single-Ended Primary Inductive Converter (SEPIC).The MCP1631HV microcontroller
is programmable, allowingthe user to modify or develop their own firmware routines to
further evaluate the MCP1631HV Multi-Chemistry Battery Charger in this application.
2.2 FEATURES
The MCP1631HV Multi-Chemistry Battery Charger has the following features:
• Input Operating Voltage Range
- +5.3V to +16V (VIN > VBATT)
• Maximum of 2A Charge Current for single cell Li-Ion
• Charge NiMH, NiCd or Li-Ion Chemisties
• Charge 1 or 2 Cell Li-Ion Batteries in Series
• Charge 1 to 4 Cells of NiMH or NiCd Batteries in Series
• Select Chemistry and Cells using push-buttons
• ON/OFF switch
• Charge Status Indication
• Programmable Charge Profile
• OV Shutdown (2.0V / Cell for NiMH/NiCd or 4.4V/Cell for Li-Ion)

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 8 ©2007 Microchip Technology Inc.
2.3 GETTING STARTED
The MCP1631HV Multi-Chemistry Battery Charger is fully assembled and tested for
charging one or two series Li-Ion Batteries or one to four series cell NiMH or NiCd bat-
teries. The charge termination for Li-Ion is based a percentage of fast charge current,
the charge termination for NiMH is based on a negative voltage change versus time or
positive temperature change versus time. This board requires the use of an external
voltage source to charge the series connected batteries with a range of +5.3V to +16V
input.Anexternalloadandthermistoris alsorequiredtoevaluatethechargerreference
design.
FIGURE 2-1: MCP1631HV Multi-Chemistry Battery Charger Charge profile,
Li-Ion.
0.0
1.0
2.0
3.0
4.0
5.0
0
15 30 45 60 75 90
105 120 135 150 165 180
Time (Minutes)
Battery Voltage (V)
Charge Current (A)
1 Cell 3,600 mA-hr Li-Ion Battery

Installation and Operation
©2007 Microchip Technology Inc. DS51697A-page 9
FIGURE 2-2: MCP1631HV Multi-Chemistry Battery Charger Charge profile,
NiMH/NiCd.
2.3.1 Power Input and Output Connection
2.3.1.1 POWERING THE MCP1631HV MULTI-CHEMISTRY BATTERY
CHARGER
1. Apply the input voltage to the input terminal block, J1. The input voltage source
should be limited to the 0V to +16V range. For nominal operation the input
voltage should be between +5.3V and +16V.
2. Connect the positive side of the input source (+) to pin 1 of J1. Connect the
negative or return side (-) of the input source to pin 2 of J1. Refer to Figure 2-3.
0.0
1.0
2.0
3.0
4.0
5.0
0
15 30 45 60 75 90
105 120 135 150
Time (Minutes)
Battery Voltage (V)
Charge Current (A)
0
10
20
30
40
50
60
Temperature (C)
3 Cell 2,000 mA-hr NiMH Batteries

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 10 ©2007 Microchip Technology Inc.
FIGURE 2-3: Setup Configuration Diagram.
2.3.1.2 APPLYING A LOAD TO THE MCP1631HV MULTI-CHEMISTRY
BATTERY CHARGER
1. To apply a load (battery pack), to the MCP1631HV Multi-Chemistry Battery
Charger, the positive side of the battery pack (B+) should be connected to pin 1
of J2. The negative side of the load (B-)should be connected to pin 5 of J2.
2. For NiMH or NiCd battery packs, a thermistor referenced to (B-) in the battery
pack should be utilized, reccomened EPCOS Inc. PN B57500M0103A005. If a
thermistor is not available or not desired, a 10 kΩresistor should be placed
between pins 4 and 5 of the battery header (J2) or the charger will detect a miss-
ing thermistor and no charge cycle will begin.

Installation and Operation
©2007 Microchip Technology Inc. DS51697A-page 11
FIGURE 2-4: Simulated Battery Load.
2.3.1.3 SELECTING BATTERY CHEMISTRY AND NUMBER OF CELLS
2.3.1.3.1 Three push buttons are used to start a charge cycle, select chemistry and
select number of series cells. There are two LED’s, (green - NiMH, red -
Li-Ion) used to indicate chemistry type and four yellow LED’s to indicate
the number of series cells selected (D6, D7, D8, D9).
2.3.1.3.2 S1 (ON/OFF) is used to start and stop the charge cycle or to enter the
programming mode. When the input voltage is within the specified
operating range (+5.3V to +16V), press and hold the ON/OFF button for 5
seconds, all LEDs with the exception of D3 should flash. Release S1 and
STATUS LED (D3) will be flash, indicating that the board is in
programming mode.
1. Press S2 (CHEM) to select the desired chemistry. Indication is provided by a red
LED (D4) (Li-Ion) or a green LED (D5) (NiMH/NiCd).
2. Press S3 (CELLS) to select the number of series cells. Indication is provided by
yellow (D6 thru D9) (1 Cell to 4 Cell LED’s) where D6 = 1 cell, D7 = 2 cell,
D8 = 3 cell and D9 = 4 cell.
3. Once the desired chemistry and number of cells is selected, press and release
S1 ON/OFF to store the settings. The selected chemistry LED and number of
series cells LED both should be illuminated.
4. To start a charge cycle, press and release S1. D3 (green) will be illuminated
indicating a charge cycle has begun, the selected chemistry LED should flash
slowly indicating normal charge cycle conditions.
5. If the chemistry LED is not flashing and the Status LED is flashing, a fault
condition has persisted for 5 attempts idicating that the charge cycle has
terminated.
6. Remove the input voltage and check the connections and verify the proper
battery pack chemistry and number of series cells.
7. Once the problem is corrected, apply the input voltage, check the chemistry and
number of series cells LEDs and press S1 to start a charge cycle.
Note: For single cell Li-Ion, a 3,600 mA-Hr. battery with internal protection
circuitryisrecommendedforevaluation.ForNiMHchargecycle,Panasonic
HHR-210AA/B2B batteries were used to develop the -dV/dt and +dT/dt ter-
mination methods.

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 12 ©2007 Microchip Technology Inc.
2.3.1.4 STATUS LED
1. The MCP1631HV Multi-Chemistry Battery Charger has an LED to indicate
charge status or fault status. Table 2-1 represents the state of the Satus LED dur-
ing various states of the charge cycle.
TABLE 2-1: STATUS OUTPUT
2.3.1.5 CHARGE PROFILE
•Li-Ion
- Qualification: Precharge at 200 mA for VCELL < 3.0V
- Constant Current = 2A for 1 Cell, 1A for 2 Cell
- Constant Voltage = 4.20V, Calibrated at board final test
- Charge Termination = 140 mA for 1 Cell and 2 Cell
- Overvoltage Detection, once detected, attempt to restart charge cycle 5 times,
if overvoltage is persistant, terminate attemtps and flash STATUS LED.
• NiMH/NiCd
- Qualification: Precharge at 200 mA for VCELL < 0.9V
- Constant Current = 1.5A for 1 Cell to 4 Cell
- Terminate Fast Charge for -dV/dT or +dT/dt
- Timed 50 mA top off charge for 1 hour
- Overvoltage Detection, once detected, attempt to restart charge cycle 5 times,
if overvoltage is persistant, terminate attemtps and flash STATUS LED.
2.3.1.6 PROGRAMMING
Header J3 is provided for in-system circuit programming.
Charge Cycle State LED
Programming Flashing (Fast)
Qualification OFF
Preconditioning ON
Constant Current Fast Charge ON
Top Off Charge ON
Charge Complete OFF
Safety Timer Fault Flashing (2 Hertz)
Cell Temperature Invalid Flashing (2 Hertz)
Battery Disconnected Flashing ( 2 Hertz)
Input Power Removed OFF

MCP1631 MULTI-CHEMISTRY
BATTERY CHARGER
REFERENCE DESIGN
©2007 Microchip Technology Inc. DS51697A-page 13
Appendix A. Schematic and Layouts
A.1 INTRODUCTION
This appendix contains the following schematics and layouts for the MCP1631
Multi-Chemistry Battery Charger Reference Design:
• Board Schematic
• Board – Top Silk Layer
• Board – Top Metal Layer
• Board – Mid1 Metal Layer
• Board – Mid2 Metal Layer
• Board – Bottom Metal Layer

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 14 ©2007 Microchip Technology Inc.
A.2 BOARD – SCHEMATIC
AK
AK
AK
AK
5
8
3
4
6
7
1
2
AK
AK
AK
AK
13 11
9 7 5 3 1
16 18 20 22 24 26 28
10 12 14
2 4 6 8
17 15 19 27 25 23 21

Schematic and Layouts
©2007 Microchip Technology Inc. DS51697A-page 15
A.3 BOARD – TOP SILK LAYER

MCP1631 Multi-Chemistry Battery Charger Reference Design
DS51697A-page 16 ©2007 Microchip Technology Inc.
A.4 BOARD – TOP METAL LAYER