MCP19111
PMBus™ Protocol-Enabled
Point-of-Load (POL) Converter
Reference Design
User’s Guide
2015 Microchip Technology Inc.
DS50002379A
Note the following details of the code protection feature on Microchip devices:
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Microchip products meet the specification contained in their particular Microchip Data Sheet.
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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
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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
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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
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Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
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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and may be superseded by updates.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
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Trademarks
The Microchip name and logo, the Microchip logo, dsPIC,
FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer,
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The Embedded Control Solutions Company and mTouch are
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Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo,
CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit
Serial Programming, ICSP, Inter-Chip Connectivity, KleerNet,
KleerNet logo, MiWi, MPASM, MPF, MPLAB Certified logo,
MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code
Generation, PICDEM, PICDEM.net, PICtail, RightTouch logo,
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© 2015, Microchip Technology Incorporated, Printed in the
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ISBN: 978-1-63277-476-7
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
DS50002379A-page 2
Microchip received ISO/TS-16949:2009 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.
2015 Microchip Technology Inc.
Object of Declaration: MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
2015 Microchip Technology Inc.
DS50002379A-page 3
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
NOTES:
DS50002379A-page 4
2015 Microchip Technology Inc.
MCP19111 PMBus™
PROTOCOL-ENABLED POL
CONVERTER REFERENCE DESIGN
USER’S GUIDE
Table of Contents
Preface ........................................................................................................................... 7
Introduction............................................................................................................ 7
Document Layout .................................................................................................. 8
Conventions Used in this Guide ............................................................................ 9
Warranty Registration.......................................................................................... 10
Recommended Reading...................................................................................... 10
The Microchip Web Site ...................................................................................... 10
Development Systems Customer Change Notification Service .......................... 11
Customer Support ............................................................................................... 11
MCP19111 PMBus™-Enabled POL Converter Reference Design License........ 11
Revision History .................................................................................................. 11
Chapter 1. Product Overview
1.1 Introduction ................................................................................................... 13
1.2 MCP19111 Device Short Overview .............................................................. 13
1.3 What is the MCP19111 PMBus™ Protocol-Enabled Point-of-Load
Converter Reference Design? ................................................................ 15
1.4 System Requirements .................................................................................. 15
1.4.1 The Development System’s Components ................................................. 16
1.5 What the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design Kit Contains? ............................................................ 16
Chapter 2. Installation and Operation
2.1 Board Features ............................................................................................. 17
2.2 Getting Started ............................................................................................. 18
2.2.1 Necessary Instruments and Tools ............................................................. 18
2.2.2 Setup Procedure ....................................................................................... 18
2.2.3 Board Testing ............................................................................................ 19
Chapter 3. Calibration Procedure
3.1 Introduction ................................................................................................... 21
3.2 Voltage Calibration ....................................................................................... 22
3.3 Current Calibration with Inductor Temperature Measurement ..................... 23
Chapter 4. Typical Performance Data, Curves and Waveforms .............................. 25
2015 Microchip Technology Inc.
DS50002379A-page 5
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
Appendix A. Schematics and Layouts
A.1 Introduction .................................................................................................. 33
A.2 Board – Schematic 1 .................................................................................... 34
A.3 Board – Schematic 2 .................................................................................... 35
A.4 Board – Top Layer ....................................................................................... 36
A.5 Board – Top Copper .................................................................................... 36
A.6 Board – Mid Layer 1 ..................................................................................... 37
A.7 Board – Mid Layer 2 ..................................................................................... 37
A.8 Board – Bottom Layer .................................................................................. 38
A.9 Board – Bottom Copper ............................................................................... 38
Appendix B. Bill of Materials (BOM) ...........................................................................39
Appendix C. Calibration Example
C.1 Introduction .................................................................................................. 41
C.2 Configuration Requirements ........................................................................ 42
C.2.1 Calibration .................................................................................................42
Worldwide Sales and Service .....................................................................................44
DS50002379A-page 6
2015 Microchip Technology Inc.
MCP19111 PMBus™
PROTOCOL-ENABLED POL
CONVERTER REFERENCE DESIGN
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 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
“DSXXXXXXXXA”, where “XXXXXXXX” 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 online help.
Select the Help menu, and then Topics to open a list of available online help files.
INTRODUCTION
This chapter contains general information that will be useful to know before using the
MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference Design.
Items discussed in this chapter include:
•
•
•
•
•
•
•
•
Document Layout
Conventions Used in this Guide
Warranty Registration
Recommended Reading
The Microchip Web Site
Development Systems Customer Change Notification Service
Customer Support
Revision History
I
WARNING
The present reference design is intended to be used only to prove the MCP19111
functionality and performance, solely in a laboratory environment. Microchip
Technology Inc. assumes no liability for any damage resulting from using the present
reference design in other purposes.
2015 Microchip Technology Inc.
DS50002379A-page 7
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
DOCUMENT LAYOUT
This document describes how to use the MCP19111 PMBus™ Protocol-Enabled
Point-of-Load Converter Reference Design as a development tool to emulate and
debug firmware on a target board, as well as how to program devices. The document
is organized as follows:
• Chapter 1. “Product Overview” – Important information about the MCP19111
PMBus™ Protocol-Enabled Point-of-Load Converter Reference Design.
• Chapter 2. “Installation and Operation” – Includes instructions on how to get
started using the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design.
• Chapter 3. “Calibration Procedure” – Includes instructions on the calibration
procedure of the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design.
• Chapter 4. “Typical Performance Data, Curves and Waveforms” – Includes
typical performance graphs of data, curves and waveforms.
• Appendix A. “Schematics and Layouts” – Shows the schematic and layout
diagrams for the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design.
• Appendix B. “Bill of Materials (BOM)” – Lists the parts used to build the
MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference
Design.
• Appendix C. “Calibration Example” – Gives an example of a calibration
procedure for the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design.
DS50002379A-page 8
2015 Microchip Technology Inc.
Preface
CONVENTIONS USED IN THIS GUIDE
This manual uses the following documentation conventions:
DOCUMENTATION CONVENTIONS
Description
Arial font:
Italic characters
Initial caps
Quotes
Underlined, italic text with
right angle bracket
Bold characters
N‘Rnnnn
Text in angle brackets < >
Courier New font:
Plain Courier New
Represents
Referenced books
Emphasized text
A window
A dialog
A menu selection
A field name in a window or
dialog
A menu path
MPLAB® IDE User’s Guide
...is the only compiler...
the Output window
the Settings dialog
select Enable Programmer
“Save project before build”
A dialog button
A tab
A number in verilog format,
where N is the total number of
digits, R is the radix and n is a
digit.
A key on the keyboard
Click OK
Click the Power tab
4‘b0010, 2‘hF1
Italic Courier New
Sample source code
Filenames
File paths
Keywords
Command-line options
Bit values
Constants
A variable argument
Square brackets [ ]
Optional arguments
Curly brackets and pipe
character: { | }
Ellipses...
Choice of mutually exclusive
arguments; an OR selection
Replaces repeated text
Represents code supplied by
user
2015 Microchip Technology Inc.
Examples
File>Save
Press ,
#define START
autoexec.bat
c:\mcc18\h
_asm, _endasm, static
-Opa+, -Opa0, 1
0xFF, ‘A’
file.o, where file can be
any valid filename
mcc18 [options] file
[options]
errorlevel {0|1}
var_name [,
var_name...]
void main (void)
{ ...
}
DS50002379A-page 9
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
WARRANTY REGISTRATION
Please complete the enclosed Warranty Registration Card and mail it promptly.
Sending in the Warranty Registration Card entitles users to receive new product
updates. Interim software releases are available at the Microchip web site.
RECOMMENDED READING
This user’s guide describes how to use MCP19111 PMBus™ Protocol-Enabled
Point-of-Load Converter Reference Design. Other useful documents are listed below.
The following Microchip documents are available and recommended as supplemental
reference resources.
MCP19110/11 Data Sheet (DS20002331)
This data sheet describes the operation and features of the MCP19110/11
digitally-enhanced power analog controller with integrated synchronous driver.
PMBus™ Monitoring Graphical User Interface User’s Guide (DS50002380)
This user’s guide describes how to use the PMBus Monitoring Graphical
User Interface (GUI).
TB3139, MCP19111 PMBus™ Firmware Technical Brief (DS90003139)
This technical brief describes how to use the MCP19111 PMBus firmware.
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
DS50002379A-page 10
2015 Microchip Technology Inc.
Preface
DEVELOPMENT SYSTEMS CUSTOMER CHANGE NOTIFICATION SERVICE
Microchip’s customer notification service helps keep customers current on Microchip
products. Subscribers will receive e-mail notification whenever there are changes,
updates, revisions or errata related to a specified product family or development tool of
interest.
To register, access the Microchip web site at www.microchip.com, click on Customer
Change Notification and follow the registration instructions.
The Development Systems product group categories are:
• Compilers – The latest information on Microchip C compilers, assemblers, linkers
and other language tools. These include all MPLAB® C compilers; all MPLAB
assemblers (including MPASM™ Assembler); all MPLAB linkers (including
MPLINK™ Object Linker); and all MPLAB librarians (including MPLIB™ Object
Librarian).
• Emulators – The latest information on Microchip in-circuit emulators.This
includes the MPLAB REAL ICE™ and MPLAB ICE 2000 In-Circuit Emulators.
• In-Circuit Debuggers – The latest information on the Microchip in-circuit
debuggers. This includes MPLAB ICD 3 In-Circuit debugger and PICkit™ 3
Debug Express.
• MPLAB® IDE – The latest information on Microchip MPLAB IDE, the Windows®
Integrated Development Environment for development systems tools. This list is
focused on the MPLAB IDE, MPLAB IDE Project Manager, MPLAB Editor and
MPLAB SIM Simulator, as well as general editing and debugging features.
• Programmers – The latest information on Microchip programmers. These include
production programmers, such as MPLAB REAL ICE In-Circuit Emulator, MPLAB
ICD 3 In-Circuit Debugger and MPLAB PM3 Device Programmer.
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://www.microchip.com/support
MCP19111 PMBUS-ENABLED POL CONVERTER REFERENCE DESIGN LICENSE
Copyright © 2015 Microchip Technology Inc. All rights reserved.
1. License Grant. Microchip licenses to you the right to use this reference design
and all related documentation (“Reference Design Materials”) for purposes of
developing your application using Microchip products. You may not re-distribute
Reference Design Materials to any third parties.
2. Warranty Disclaimer. Reference Design Materials are provided for your convenience only and may be superseded by updates. These materials will not be
deemed to modify Microchip’s standard warranty for its products. It is your
responsibility to: (1) ensure that the Reference Design Materials, and your use
thereof, meet your requirements; and (2) test your application.
2015 Microchip Technology Inc.
DS50002379A-page 11
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
REFERENCE DESIGN MATERIALS ARE PROVIDED “AS IS” WITHOUT
WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY, TITLE,
NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR PURPOSE.
3. Limit on Liability. IN NO EVENT WILL MICROCHIP BE LIABLE OR
OBLIGATED UNDER CONTRACT, NEGLIGENCE, STRICT LIABILITY,
CONTRIBUTION, BREACH OF WARRANTY, OR OTHER LEGAL EQUITABLE
THEORY ANY DIRECT OR INDIRECT DAMAGES OR EXPENSES INCLUDING
BUT NOT LIMITED TO ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL
DAMAGES, LOST PROFITS OR LOST DATA, COST OF PROCUREMENT OF
SUBSTITUTE GOODS, TECHNOLOGY, SERVICES, ANY CLAIMS BY THIRD
PARTIES (INCLUDING BUT NOT LIMITED TO ANY DEFENSE THEREOF), OR
OTHER SIMILAR COSTS. 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.
TO THE FULLEST EXTENT PERMITTED BY LAW, MICROCHIP’S LIABILITY IS
CAPPED AT THE AMOUNT YOU PAID DIRECTLY TO MICROCHIP FOR THESE
REFRENCE DESIGN MATERIALS.
4. Governing Law. THIS LICENSE WILL BE GOVERNED BY AND
CONSTRUCTED UNDER THE LAWS OF THE STATE OF ARIZONA AND THE
UNITED STATES WITHOUT REGARD TO CONFLICTS OF LAWS PROVISIONS.
Licensee agrees that any disputes arising out of or related to this License, Software
or Reference Design Materials will be brought in the courts of State of Arizona. The
parties agree to waive their rights to a jury trial in actions relating to this License.
REVISION HISTORY
Revision A (June 2015)
This is the initial release of this document.
DS50002379A-page 12
2015 Microchip Technology Inc.
MCP19111 PMBus™
PROTOCOL-ENABLED POL
CONVERTER REFERENCE DESIGN
USER’S GUIDE
Chapter 1. Product Overview
NOTICE TO CUSTOMERS
The present reference design is intended to be used only to prove the MCP19111 functionality
and performance, solely in laboratory environment. Microchip Technology Inc. assumes no
liability for any damage resulting from using the present reference design in other purposes.
1.1
INTRODUCTION
This chapter provides an overview of the MCP19111 PMBus™ Protocol-Enabled
Point-of-Load Converter Reference Design and covers the following topics:
• MCP19111 Device Short Overview
• What is the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design?
• What the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design Kit Contains?
CAUTION
All the functionalities described in this document are specific to the original firmware
loaded in the MCP19111. Once the user software is loaded, the PMBus communication
and board settings become the user’s responsibility.
1.2
MCP19111 DEVICE SHORT OVERVIEW
The MCP19111 device is a highly integrated, mixed signal, Analog Pulse-Width
Modulation (PWM) Current mode controller with an integrated microcontroller core for
synchronous DC/DC step-down applications. Since the MCP19111 uses traditional
analog control circuitry to regulate the output of the DC/DC converter, the integration of
the PIC® microcontroller mid-range core is used to provide complete customization of
the device operating parameters, start-up and shutdown profiles, protection levels and
Fault handling procedures.
The MCP19111 is designed to efficiently operate from a single, 4.5V to 32V supply. It
features integrated synchronous drivers, a bootstrap device, internal linear regulator and
4000 words of nonvolatile memory, all in a space-saving, 28-pin 5 mm x 5 mm QFN
package.
PMBus™ or I2C™ can be used by a host to communicate with, or modify the operation of,
the MCP19111. A subset of the commands contained in the “PMBus™ Power System
Management Protocol Specification, Revision 1.1” are supported by the ARD00609 board.
An internal 5V rail provides power to the PIC MCU and is also present on the VDD pin.
It is recommended that a 1 μF capacitor be placed between VDD and PGND. The VDD
pin may also be directly connected to the VDR pin or connected through a low-pass
RC filter. The VDR pin provides power to the internal synchronous driver.
2015 Microchip Technology Inc.
DS50002379A-page 13
GPA6
VIN
GPB1
TRACK
PGOOD
CNTL
ADDR1
ADDR0
SYNC
SMBus™ Alert
SCL
SDA
2015 Microchip Technology Inc.
ICDDAT
MPLAB® X ICD
Programmer
ICDCLK
MCLR
FIGURE 1-1:
MCP19111 Typical Application.
GPA0
HDRV
GPA2
BOOT
GPB2
PHASE
+VOUT
GPA3
LDRV
-VOUT
GPB7
VDD
GPB6
MCP19111
VDR
GPA1
+ISEN
GPA4
-ISEN
GPA7
+VSEN
GPB0
-VSEN
GPB4
PGND
GPB5
GND
GPA5
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
DS50002379A-page 14
VIN
Product Overview
1.3
WHAT IS THE MCP19111 PMBus™ PROTOCOL-ENABLED POINT-OF-LOAD
CONVERTER REFERENCE DESIGN?
The MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference
Design demonstrates how the MCP19111 device operates in a synchronous buck
topology over a wide input voltage and load range. Nearly all operational and control
system parameters are programmable by utilizing the integrated PIC microcontroller.
For precise measurements of the output current, a precision op amp (MCP6061) and
an inductor temperature sensor (MCP9700) are provided. The output current may be
measured and calibrated using an internal or external op amp. The temperature
compensation may be performed by temperature measurement or by second order
polynomial approximation.
The PMBus Monitoring Graphical User Interface (GUI) can be used to program the
functioning parameters and to check the operational status. To simplify the connection,
a USB to PMBus converter is implemented on board, allowing a standard interface to
any Windows® computer.
Alternatively, the user can program the MCP19111 using self-developed firmware (see
Section 1.4.1 “The Development System’s Components”), tailoring it to the
application.
The evaluation board contains headers for In-Circuit Serial Programming™ (ICSP™)
as well as I2C and mini-USB communication, pull-up and pull-down resistor pads and
test point pads on each GPIO pin, and a push button for system development. The
MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference Design is
also intended to demonstrate an optimized Printed Circuit Board (PCB) layout that
minimizes parasitics, while increasing efficiency and power density.
Proper PCB layout is critical to achieve optimum MCP19111 operation, as well as
power train efficiency and noise minimization.
1.4
SYSTEM REQUIREMENTS
To operate the board, the following tools are required:
• Microsoft® .NET Framework 4.5 or higher
• PMBus Monitoring Graphical User Interface: This graphical user interface allows
monitoring and changing input and output parameters for any device that has an
incorporated PMBus™ protocol. For installation, operation and other system
requirements, see the “PMBus™ Monitoring Graphical User Interface User’s
Guide” (DS50002380).
WARNING
Any changes in the Settings tab from the Developer menu may result in system
instability and/or permanent damage of the board, and is the user’s sole responsibility
to take the necessary precautions.
2015 Microchip Technology Inc.
DS50002379A-page 15
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
1.4.1
The Development System’s Components
To redevelop the board firmware, the following may be required:
• MCP19111 MPLAB® X IDE Graphical User Interface Plug-In: This graphical user
interface simplifies the configuration of the MCP19111. It is user-installed and
resides within the MPLAB X IDE. The “MCP19110/11/18/19 – Buck Power Supply
Graphical User Interface User’s Guide” (DS50002113) describes the plug-in
installation procedure, as well as how to use it.
• MPLAB® X Integrated Development Environment (IDE): This is a complete
software development environment that links the software and hardware
development. This is a free tool, available from Microchip, that supports device
configuration, advanced programming, as well as debug support. The GUI resides
inside the MPLAB X IDE.
• MPLAB® XC8 Compiler: The firmware described above is coded in C and thus
requires a C compiler. C compilers are available for free from Microchip’s
web site.
• Configuration tools:
- PICkit™ Serial Analyzer: This communication tool may be used to configure
the evaluation board. The PICkit Serial Analyzer is recommended and is
available for purchase on microchipDIRECT.
- PICkit 3 In-Circuit Debugger/Programmer: A programming tool is required to
reprogram the evaluation board. The PICkit 3 or MPLAB ICD 3 is
recommended and they are available for purchase on microchipDIRECT.
- Any other user-preferred I2C connection for further board development.
To resume the original functionality of the ARD00609, the user can download the
00609_RevA1.hex file from Microchip’s web site and upload it in the MCP19111 using
a PICkit 3 In-Circuit Debugger/Programmer.
1.5
WHAT THE MCP19111 PMBus™ PROTOCOL-ENABLED POINT-OF-LOAD
CONVERTER REFERENCE DESIGN KIT CONTAINS?
This MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference
Design kit includes the following items:
• MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference
Design board (ARD00609)
• Important Information Sheet
DS50002379A-page 16
2015 Microchip Technology Inc.
MCP19111 PMBus™
PROTOCOL-ENABLED POL
CONVERTER REFERENCE DESIGN
USER’S GUIDE
Chapter 2. Installation and Operation
2.1
BOARD FEATURES
The MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference
Design was developed to provide a compact, low-cost and highly efficient step-down
conversion for low-to-medium output currents.
The key features of this board include:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Input Voltage Range: 8V to 14V
Output Voltage: 1.2V (can be adjusted by software from 0.1 to 3.6V)
Maximum Output Current: 20A
88% Typical Efficiency at 1.2V/15A output and 12V input
500 kHz Switching Frequency (can be software adjusted from 100 kHz to
1.6 MHz)
On-Board High-Performance Power MOSFET Transistors
Overcurrent and Overtemperature Protection
Status Report (including errors, input voltage, output voltage and current) via the
PMBus Communication Protocol
Precision Op Amp for Accurate Output Current Measurement
Inductor Temperature Sensor
Calibration of Output Voltage
Calibration of Output Voltage and Output Current Measurements (via PMBus)
Undervoltage Lockout (UVLO) with Programmable (via software) Thresholds
Output Overvoltage, Undervoltage and Overcurrent Lockout, Programmable via
Software
For Advanced Users (use with caution): Control Loop Parameters and MOSFET’s
Switching Dead Time can also be Adjusted by Software.
2015 Microchip Technology Inc.
DS50002379A-page 17
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
2.2
GETTING STARTED
The MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter Reference
Design is fully assembled and tested to evaluate and demonstrate the MCP19111
capabilities.
2.2.1
•
•
•
•
•
•
•
•
Necessary Instruments and Tools
Adjustable DC Power Supply with 0V-15V/5 ADC Range Output Capability
Electronic Load with at least 25A Current Capability and Load Stepping Capability
Digital Oscilloscope with a Minimum Bandwidth of 50 MHz
Digital Voltmeter/Ammeter
Optionally, a Network Analyzer/Bode Plot Analyzer for Control Loop Analyzing
PC with PMBMonitor GUI Pre-Installed
USB-A to mini-USB Cable
Wires for Connections, Capable to Sustain High Currents:
- 5A for the connection between the adjustable DC power supply and board
- 20A for the connection between the board and the electronic load
2.2.2
Setup Procedure
To power-up the MCP19111 PMBus™ Protocol-Enabled Point-of-Load Converter
Reference Design, the following steps must be completed:
1. Connect the electronic load to the J2 connector of the demo board; the Positive
(+) and Negative (–) connector pins are marked on the board silkscreen.
2. Connect the adjustable DC power supply to the J1 connector of the demo board;
the Positive (+) and Negative (–) connector pins are marked on the board
silkscreen.
3. Supply 12V from the adjustable power source.
4. Connect the test board to a PC with the PMBMonitor GUI pre-installed via a
USB-A to mini-USB cable (J3 connector).
5. After powering up, press the push button, BT1, to turn on the output voltage.
Alternatively, the output may be turned on from the PMBMonitor GUI ON button
(under Status>Operation Panel).
6. The board is factory set to deliver 1.2V at 20A maximum, with the loop adjusted
for optimum performance and current measurement performed via the auxiliary
op amp. If different settings are desired, changes may be performed in
several ways:
- Via the PMBus to USB on-board interface – refer to the “PMBus™
Monitoring Graphical User Interface User’s Guide” (DS50002380)
for details.
- Via PMBus – the user must connect a PMBus master via the I2C interface
of the board, connector J1.
- By user-developed software that may be loaded into the MCP19111
J2 connector using PICkit™ 3 or another suitable programming tool.
DS50002379A-page 18
2015 Microchip Technology Inc.
Installation and Operation
2.2.3
Board Testing
The typical testing setup is depicted in Figure 2-1. Table 2-1 shows all the available test
points on the board. Table 2-2 describes the ICP/I2C communication pins’ function.
PROG on the J2 connector is used with the PICkit 3 in-circuit programmer/debugger.
The user can connect various instruments at the listed test points to evaluate the
parameters of the converter. The typical performance data, curves and waveforms are
presented in Chapter 4. “Typical Performance Data, Curves and Waveforms”.
USB
TP33
RD2
TP34
TP35
TP12
TP3
TP5
TP2
TP10
RC2
RC1
TP1
RD1
ICP/I2C
TP4
J1
TP32
BT1
BODE PLOT
ANALYZER
TP31
TP14
A
B
TP30
TP18
J2
PROG
TP41
V
TP40
TP16
V
ADJ
DC
PS
+
+
TP17
FIGURE 2-1:
LOAD
Max
20A
-
Typical Test Setup.
2015 Microchip Technology Inc.
DS50002379A-page 19
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
TABLE 2-1:
TEST POINT DESCRIPTION
Test Point
Name
TP1
GPA0
Connects to GPA0 or Analog Test Output (Note 1)
TP2
GPB1
Connects to GPB1 (Note 1)
TP3
GPB7
By Default, used as Power-on Signal (connected to BT1) (Note 1)
TP4
GPA1
Connects to GPA1 (Note 1)
TP5
GPB2
By Default, used for Inductor Temperature Measurement (Note 1)
TP10
GPB6
Connects to GPB6 (Note 1)
TP12
GPB0/SDA
TP14
GPA7/SCL
TP16
VIN
Input Voltage
TP17, TP41
GND
Power GND
TP18
CH A
Injection Point for Loop Measurement
TP30, TP31, TP32,
TP33, TP34, TP35
SGND
Signal GND
TP35
GPA3
By Default, used as External Current Measurement Input (Note 1)
TP40
VOUT
Output Voltage and Channel B Injection Point for Loop Measurement
Note 1:
Description
Connects to GPB0/SDA (Note 1)
Connects to GPA7/SCL (Note 1)
For a detailed description of the port pin functions, see the “MCP19110/11 Data Sheet”.
TABLE 2-2:
Note:
DS50002379A-page 20
ICP/I2C™ COMMUNICATION CONNECTOR J1 PINS
Pin Number
Description
1
Do not connect
2
Do not connect
3
GND
4
SCL
5
SDA
6
GND
Communication over the USB interface uses the same I2C bus; normally,
the user should not simultaneously connect the USB and the ICP/I2C
interfaces.
2015 Microchip Technology Inc.
MCP19111 PMBus™
PROTOCOL-ENABLED POL
CONVERTER REFERENCE DESIGN
USER’S GUIDE
Chapter 3. Calibration Procedure
3.1
INTRODUCTION
In order to increase the accuracy of the output voltage setting, output voltage
measurement and output current reading, a calibration procedure must be performed.
It is recommended to use the Microchip dedicated PMBMonitor GUI that can be
downloaded from the board’s web page, as it performs all needed computations and
greatly simplifies the procedures.
For more information on the mathematical basis and implementation of the calibration
procedures, refer to the Appendix C. “Calibration Example”.
Figure 3-1 shows the PMBMonitor GUI Interface Calibration tab. It also identifies the
main panels used in the calibration procedures described in this chapter.
For more information on the Installation and Operation of the PMBMonitor GUI, refer to
the “PMBus™ Monitoring Graphical User Interface User’s Guide” (DS50002380).
Calibration
Tab
Developer
Menu
IOUT
Settings Panel
VOUT
Settings Panel
LOG
Text Box
STATUS Bar
Code
Label
FIGURE 3-1:
PMBMonitor GUI – Calibration Tab.
2015 Microchip Technology Inc.
DS50002379A-page 21
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
3.2
VOLTAGE CALIBRATION
Follow these steps to perform the voltage calibration procedure:
1. Select Developer from the PMBMonitor GUI main menu, then choose the
Calibration tab.
2. In the VOUT Settings Panel, press the Read button.
PMBus™
Transmitted
Value
Measured
Value
Input Field
Reads VOUT
from the Board
Sends Data to
Board
FIGURE 3-2:
VOUT Settings Panel Description.
3. On the board, measure with an accurate voltmeter the output voltage between
the TP41 and TP40 test points.
4. Input the value obtained in Step 3 in the “Measured” field, then press the Send
button to update the data on the board.
5. Verify that both the output voltage (measured with the voltmeter) and the
PMBMonitor transmitted value that appears on the screen are correct.
6. Go to the Status menu, and in the Operation Panel, press the StoreALL button
to keep the actual value after power-off.
StoreALL
Button
FIGURE 3-3:
DS50002379A-page 22
Status Menu – Operation Panel.
2015 Microchip Technology Inc.
Calibration Procedure
3.3
CURRENT CALIBRATION WITH INDUCTOR TEMPERATURE
MEASUREMENT
1. Select Developer from the PMBMonitor GUI main menu, then choose the
Calibration tab.
2. Choose a low test current (except zero, for example, 1A) and write the value in
the first “Current” field in the IOUT Settings Panel. Set this current on the external
load as accurate as possible. Press the corresponding Read button. A value will
appear in the corresponding “Voltage” field.
Updates the Value
of the Temperature
Coefficient
Input the Low
Test Current
Updateable Values
after Pressing
Calculate Button
Input the High
Test Current
Updates the
Current Calibration
FIGURE 3-4:
IOUT Settings Panel.
3. Choose a high test current (at best, the highest load current, for example, 17A),
write the value in the second “Current” field and set this output current on the
external load. Press the corresponding Read button. Write down the value that
appears in the second “Voltage” field.
4. Press the Calculate button. The values in the “ADC(T0)”, “Coefficient-X1” and
“Coefficient-X0” fields may update once the calculations are done.
5. Press Send from the bottom of the IOUT Settings Panel.
WARNING
Keep constant board temperature around ambient during Steps 2 to 5; therefore, all
these measurements should be done as fast as possible and/or provide adequate
cooling.
2015 Microchip Technology Inc.
DS50002379A-page 23
MCP19111 PMBus™ Protocol-Enabled POL Converter Reference Design
Steps 6-12 are used to calibrate the temperature coefficient. Note that these steps
apply only when a different inductor and/or layout is used.
6. Write down the T0 value from the “ADC(T0)” field.
7. Maintain the high-current output and allow the board to heat up (70-80°C is the
optimum).
8. Press the high-current corresponding Read button and the Calculate button to
update the values. Remember the updated value of the second voltage.
9. Compute the difference between the high-current voltage obtained in Step 8 and
the one written down (see Step 3).
10. Compute the difference between the T0 value updated on Step 8 and the one
written down (see Step 6).
11. Compute as the voltage difference, divided by the last second voltage value,
divided again by the T0 difference (see example in Equation C-5)
( Step 9:Step 8:Step 10). Multiply the value by 16384; write the rounded to
next integer value of the result in the “ALPHA” field and press the corresponding
Send button at the right.
12. Go to the Status menu, and in the Operation Panel, press the StoreALL button
to preserve the actual value after power-off.
DS50002379A-page 24
2015 Microchip Technology Inc.
MCP19111 PMBus™
PROTOCOL-ENABLED POL
CONVERTER REFERENCE DESIGN
USER’S GUIDE
Chapter 4. Typical Performance Data, Curves and Waveforms
This chapter shows examples of the parameters used for converter and performance
curves, and waveforms.
TABLE 4-1:
CONVERTER PARAMETERS
Parameter
Input Voltage Range (V)
Value
Comments
8-14
—
Output Voltage (V)
1.2
±2.5% Tolerance
Maximum Output Current (A)
20
Steady-State Output Current
Output Voltage Ripple (mV)
