MICROCHIP MCP1601 Technical data

MCP1601

Evaluation Board (Rev. 1)

User’s Guide

 2004 Microchip Technology Inc. DS51511A

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 Digit al Millennium Copyright Act. If suc h a c t s
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

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and may be superseded by updates.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.
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EELOQ, microID, MPLAB, PIC, PICmicro,

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© 2004, Microchip Technology Incorporated, Printed in the
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Printed on recycled paper.

Microchip received ISO/TS-16949:2002 quality system certification for
its worldwide headquarters, design and wafer fabrication facilities in
Chandler and Tempe, Arizona and Mountain View, California in
October 2003. The Company’s quality system processes and
procedures are for its PICmicro
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.

®

8-bit MCUs, KEELOQ

®

code hopping

DS51511A-page ii  2004 Microchip Technology Inc.

MCP1601 Evaluation Board

(Rev. 1) User Guide

Table of Contents

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

Chapter 1. Product Overview........................................................................................ 5

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

1.2 What is the MCP1 60 1 E valuation Bo a rd (R e v . 1)? .................... .............. 6

1.3 What the MCP1601 Evaluation Board (Rev. 1) kit includes ..................... 6

Chapter 2. MCP1601 Evaluation Board (Rev. 1)..........................................................7

2.1 Introduction ...............................................................................................7

2.2 Features ...................................................................................................7

2.3 Getting Started ......................................................................................... 7

2.4 Test Points ................................................................................................ 9

Appendix A. Schematic and Layouts ........................................................................11

A.1 Introduction .............................................................................................11

A.2 Board Schematic ................................................................................... 12

A.3 Board - Top Layer .................................................................................13

A.4 Board - Bottom Layer ............................................................................ 14

Appendix B. Bill-Of-Materials (BOM) ......................................................................... 15

Worldwide Sales and Service ....................................................................................16

 2004 Microchip Technology Inc. DS51511A-page iii

MCP1601 Evaluation Board (Rev. 1) User Guide

NOTES:

DS51511A-page iv  2004 Microchip Technology Inc.

MCP1601 Evaluation Board

(Rev. 1) User’s Guide

Preface

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

®

IDE

INTRODUCTION

This chapter contains general information that will be useful to know before using the
MCP1601 Evaluation Board (Rev. 1). Items discussed in this chapter include:

• About Th is Guide

• Recommended Reading

• The Microchip Web Site

• Customer Support

ABOUT THIS GUIDE

Document Layout

This document describes how to use MCP1601 Evaluation Board (Rev. 1) as a devel­opment tool to emulate and debug firmware on a target board. The manual layout is as
follows:

• Chapter 1: Product Overview – Important information about the MCP1601
Evaluation Board (Rev. 1).

• Chapter 2: MCP1601 Evaluation Board (Rev. 1) – Includes instructions on how
to get started, as well as a description of the evaluation board.

• Appendix A: Schematic and Layouts – Shows the schematic and layout
diagrams for the MCP1601 Evaluation Board (Rev. 1).

• Appendix B: Bill-of-Materials – Lists the parts used to build the MCP1601
Evaluation Board (Rev. 1).

 2004 Microchip Technology Inc. DS51511A-page 1

MCP1601 Evaluation Board (Rev. 1) User’s Guide

Conventions Used in this Guide

This manual uses the following docum entat io n conven tion s:

DOCUMENTATION CONVENTIONS

Description Represents Examples

Arial font:

Italic characters Referenced books MPLAB

Emphasized text ...is the only comp ile r...

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

Underlined, italic text with
right angle bracket

Bold characters A dialog button Click OK

‘bnnnn A binary number where n is a

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

Courier font:

Plain Courier Sample source code #define START

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

0xnnnn A hexadecimal number wher e

Square brackets [ ] Optional arguments mcc18 [options] file

Curly brackets and pipe
character: { | }

Ellipses... Replaces r epeated text var_name [,

A menu path File>Save

A tab Click the Power tab

digit

Filenames autoexec.bat
File paths c:\mcc18\h
Keywords _asm, _endasm, static
Command-line options -Opa+, -Opa-
Bit values 0, 1

n is a hexadecimal digit

Choice of mutually exclusive
arguments; an OR selection

Represents code supplied by
user

“Save project before build”

‘b00100, ‘b10

any valid filename

0xFFFF, 0x007A

[options]
errorlevel {0|1}

var_name...]
void main (void)

{ ...
}

®

IDE User’s Guide

RECOMMENDED READING

This user's guide describes how to use MCP1601 Evaluation Board (Rev. 1). Other
useful documents are listed below and are available and recommended as
supplemental reference resources.

MCP1601 Data Sheet (DS21896)

This data sheet provides detailed information regarding the MCP1601 product family.

Application Note 793, “Power Management in Portable Applications:
Understanding the Buck Switchmode Power Converter”, (DS00793)

This application note outlines a design procedure for buck regulators.

DS51511A-page 2  2004 Microchip Technology Inc.

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 (FAQ), 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

• Development Systems Information Line

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
In addition, there is a Development Systems Information Line which lists the latest

versions of Microchip's development systems software products. This line also
provides information on how customers can receive currently available upgrade kits.

The Development Systems Information Line numbers are:
1-800-755-2345 – United States and most of Canada
1-480-792-7302 – Other Interna tio nal Loca tio ns

Preface

 2004 Microchip Technology Inc. DS51511A-page 3

MCP1601 Evaluation Board (Rev. 1) User’s Guide

NOTES:

DS51511A-page 4  2004 Microchip Technology Inc.

Chapter 1. Product Overview

1.1 INTRODUCTION

The MCP1601 Evaluation Board (Rev. 1) is designed to demonstrate the use of the
MCP1601 Synchronous Buck Regulator in a step-down, inductor-based DC/DC
converter application.

This document describes the capabilities of the MCP1601 Evaluation Board (Rev. 1)
and how to select the desired synchronous converter operating mode, and to program
the output voltage.

Note: This users guide applies to the 102-00033 MCP1601 Evaluation Board

The MCP1601 Evaluation Board (Rev. 1) Schematic is shown is Figure 1-1.

MCP1601 Evaluation Boa rd

(Rev. 1) User Guide

(Rev . 1). There is another version of the MCP1601 evaluation board that
uses a different component set and is supplied with a separate user’s
guide.

FIGURE 1-1: MCP1601 Evaluation Board (Rev. 1) Block Diagram.

 2004 Microchip Technology Inc. DS51511A-page 5

MCP1601 Evaluation Board (Rev. 1) User Guide

1.2 WHAT IS THE MCP1601 EVALUATION BOARD (REV. 1)?

The MCP1601 is a 500 mA synchronous buck regulator. Both the high-side buck
P-channel and the low-side N-channel switches are integrated within the device. The
integrated synchronous switch makes the MCP1601 very efficient, even when convert­ing unregulated input voltages to low-voltage, fixed outputs. This evaluation board is
designed for a wide range of output voltages and currents. For specific applications,
smaller inductors, shielded inductors, tantalum capacitors and different output voltage
settings can improve the total DC/DC converter performance and cost.

1.3 WHAT THE MCP1601 EVALUATION BOARD (REV. 1) KIT INCLUDES

This MCP1601 Evaluation Board (Rev. 1) Kit includes:

• The MCP1601 Evaluation Board (Rev. 1) (102-00033)

• MCP1601 Evaluation Board (Rev. 1) User’s Guide (DS51511)

• MCP1601 Data Sheet (DS21762)

DS51511A-page 6  2004 Microchip Technology Inc.

Chapter 2. MCP1601 Evaluation Board (Rev. 1)

2.1 INTRODUCTION

This chapter provides detailed information illustrating how to apply input power, con­nect load, select output voltage set points and select the operating mode for the
MCP1601 Evaluation Board (Rev. 1). Board test point descriptions are also provided.

2.2 FEATURES

The MCP1601 device can operate in three different modes of operation to optimize the
efficiency of the voltage conversion. The three operating modes are:

• Automatic switching from PFM mode to PWM mode, and back

• Synchronization to external oscillator

• Fixed-frequency forced PWM mode

The MCP1601 output voltage is adjustable and is set by two external divider resistors.
A two-position switch is used on the MCP1601 Evaluation Board (Rev. 1) to change the
resistance of the external divider and adjust the output voltage to four different settings.
These output voltage settings are: 1.8V, 2.05V, 2.45V and 3.28V.

MCP1601 Evaluation Boa rd

(Rev. 1) User Guide

2.3 GETTING STARTED

2.3.1 Applying Power to the Board

Two surface-mount test points are used to apply power to the MCP1601 Evaluation
Board (Rev. 1). For proper operation, the input voltage range is 2.7V < +V
for all operating conditions. The MCP1601 has an internal Undervoltage Lockout
(UVLO) that will prevent the board from operating when the input voltage is below the
specified 2.7V minimum.

1. Connect the positive side of the external power supply (+) to the +V

2. Connect the negative side (GND) of the external power supply to the P

point, located to the left of the +V

2.3.2 Connecting a Load to the Board

To connect an external load to the board, the +V

1. Connect the positive side of the load to the +V

side of the load to the P
The MCP1601 output is rated for 500 mA (maximum) continuous current. The
output is protected against over current and short circuit conditions.

2.3.3 Enabling the MCP1601 - Using Switch SW1, Position 1

Switch SW1, position 1 is used to determine the Shutdown mode for the MCP1601
device. With switch S W
the output of the MCP1601 device is enabled. When switch SW
left, the MCP1601 device is in a low quiescent current Shutdown mode and the output
is disabled.

< +5.5V

IN

test point.

IN

test

test point.

OUT

GND

test point.

IN

and P

OUT

pin and the negative or ground

test point, located to the right of the +V

GND

, position 1 pushed to the right, the SHDN pin is pulled up and

1

OUT

test points are used.

GND

, position 1 is to the

1

 2004 Microchip Technology Inc. DS51511A-page 7

MCP1601 Evaluation Board (Rev. 1) User Guide

2.3.4 Selecting the Operating Mode - Using Switch SW1, Position 2

The multi-function SYNC/PWM pin on the MCP1601 is used to set the operating mode
of the device. The three operating modes are:

• Automatic switching from PFM mode to PWM mode, and back

• Synchronization to external oscillator

• Fixed-frequency forced PWM mode
To select automatic PFM/PWM mode:

1. Slide switch SW
mode, the MCP1601 device will automatically select the most efficient operating
mode by approximating the load current internally.

To synchronize the MCP1601 switching frequency to an external oscillator:

1. Slide switch SW
SYNC/PWM test point located below and to the right of switch SW
test point. See the MCP1601 datasheet (DS21762) for external clock specifica­tions. When synchronizing to an external oscillator, the MCP1601 will operate in
the Fixed-frequency mode at the same frequency as the external oscillator.

To select the Fixed-frequency mode that operates off of the 750 kHz internal oscillator:

1. Slide switch SW
SYNC/PWM pin high and force PWM operation from the internal oscillator,
making the MCP1601 device independent of external load conditions.

, position 2 to the left (or off) position. While operating in this

1

, position 2 to the left. Connect the external oscillator to the

1

1

, position 2 to the right (or on) position. This will tie the

1

and the A

GND

2.3.5 Selecting the MCP1601 output voltage

Switch SW2 is used to select the output voltage. Refer to Table 2-1 to choose one of
the pre-selected output voltages.

T ABLE 2-1: SWITCH SETTINGS FOR PRE-SELECTED OUTPUT VOLTAGES

SW2, Position 1 SW2, Position 2 V

OFF OFF 3.28V
OFF ON 2.45V

ON OFF 2.05V
ON ON 1.8

The output voltage for the MCP1601 device is determined by using the following
equation.

EQUATION 2-1:

R



2

V

OUT

Where:

= 0.8V, typical

V

REF

R

=200kΩ for the evaluation board

4

is set by the parallel combination of R1, R2 and R

R

2

V

=

REF

------ -

1

+



R



4

OUT

3

DS51511A-page 8  2004 Microchip Technology Inc.

MCP1601 Evaluation Board (Rev. 1) User Guide

2.4 TEST POINTS

2.4.1 Shutdown (SHDN)

The SHDN (or shutdown) test point can be used to either monitor the level of the
shutdown pin or as an input to the shutdown pin of the MCP1601 device. With switch
SW

2.4.2 SYNC/PWM

The SYNC/PWM pin can be used to either monitor the level of the SYNC/PWM pin or
as an input to the MCP1601 device. With switch SW
1MΩ resistor will pull the pin low.

To synchronize to an external oscillator:

1. With switch SW

, position 1 in the off position, a 1 MΩ resistor will pull the pin low.

1

, position 2 in the off position, a

1

, position 2 in the off position, connect the external oscillator to

1

the SYNC/PWM test point.

2.4.3 Analog Ground (A

The analog ground (or A

) can be used as a quiet ground connection. When using

GND

GND

)

the external oscillator synchronization function, connect the return or ground of the
external oscillator to the A

test point.

GND

 2004 Microchip Technology Inc. DS51511A-page 9

MCP1601 Evaluation Board (Rev. 1) User Guide

NOTES:

DS51511A-page 10  2004 Microchip Technology Inc.

Appendix A. Schematic and Layouts

A.1 INTRODUCTION

This appendix contains the schematic and board layout diagrams for the MCP1601
Evaluation Board (Rev. 1).

The MCP1601 Evaluation Board (Rev. 1) is constructed using one silk-screen layer and
two , 1 oz. metal wiring layers. The bottom metal wiring layer is a single ground plane
routed to partition the P
pin on the MCP1601 device.

Diagrams included in this appendi x:

• Board Schematic

• Top Metal Layer

• Bottom Metal Layer

MCP1601 Evaluation Boa rd

(Rev. 1) User Guide

high-current return pin from the small-signal A

GND

GND

return

 2004 Microchip Technology Inc. DS51511A-page 11

MCP1601 Evaluation Board (Rev. 1) User Guide

A.2 BOARD SCHEMATIC

M

DS51511A-page 12  2004 Microchip Technology Inc.

A.3 BOARD - TOP LAYER

12

 2004 Microchip Technology Inc. DS51511A-page 13

MCP1601 Evaluation Board (Rev. 1) User Guide

A.4 BOARD - BOTTOM LAYER

12

DS51511A-page 14  2004 Microchip Technology Inc.

MCP1601 Evaluation Boa rd

(Rev. 1) User Guide

Appendix B. Bill-Of-Materials (BOM)

TABLE B-1: BILL-OF-MATERIALS

Qty Reference Description Manufacturer Part Number

1 R1 Resistor, 1.21 MΩ, 1/10W, 1%, 0603 SMD Yageo America 9C06031A1214FKHFT

®

1 R2 Resistor, 634 kΩ, 1/16W, 1%, 0603 SMD Panasonic
1 R3 Resistor, 619 kΩ, 1/16W, 1%, 0603 SMD Panasonic - ECG ERJ-3EKF6193V
1 R4 Resistor, 200 kΩ ,1/16W, 1%, 0603 SMD Panasonic - ECG ERJ-3EKF2003V
2 R5, R6 Resistor, 1.00 MΩ, 1/16W, 1%, 0603 SMD Panasonic - ECG ERJ-3EKF1004V
2 C1, C2 Capacitor, 10 µF, 6.3V, Ceramic, X5R 0805 Panasonic - ECG ECJ-2FB0J106M
1 C3 Capacitor, CERAMIC 68 pF 50V,

0603 SMD
1 L1 Inductor Power Shield, 10µH, SMD Coiltronics
2 SW1, SW2 Switch Dip, 2pos, Half Pitch, SMT C&K™. TDA02H0SK1
2 PGND Test Point Compact, SMT Keystone

1 AGND Test Point Compact, SMT Keystone

1 +VIN Test Point Compact, SMT Keystone

1 +VOUT Test Point Compact, SMT Keystone

1 SHDN Test Point Compact, SMT Keystone

1 SYNC/PWM Test Point Compact, SMT Keystone

4 Bumpons - Protective Products 3M
1 U1 MCP1601 Buck Regulator Microchip

Panasonic - ECG ECJ-1VC1H680J

Electronics

Electronics

Electronics

Electronics

Electronics

Electronics

Technology Inc

- ECG ERJ-3EKF6343V

®

SD14-100

5016

®

5016

5016

5016

5016

5016

®

SJ5003-0
MCP1601I

 2004 Microchip Technology Inc. DS51511A-page 15

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DS51511A-page 16  2004 Microchip Technology Inc.