MCP1631HV
Digitally Controlled
Programmable Current Source
Reference Design
© 2009 Microchip Technology Inc.
DS51798A
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ECONOMONITOR, FanSense, In-Circuit Serial
Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB
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DS51798A-page ii
© 2009 Microchip Technology Inc.
MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE
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 ................................................................................... 4
Chapter 1. Product Overview
1.1 Introduction ..................................................................................................... 5
1.2 What is the MCP1631HV Digitally Controlled Programmable Current
Source Reference Design? ...................................................................... 6
1.3 What the MCP1631HV Digitally Controlled Programmable Current
Source 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 .................................................................................................. 17
A.2 Board – Schematic ....................................................................................... 18
A.3 Board – Top Solder Pads and Silk-Screen Layers ...................................... 19
A.4 Board – Top Copper Layer .......................................................................... 20
A.5 Board – Bottom Copper Layer ..................................................................... 21
Appendix B. Bill Of Materials (BOM)
Appendix C. Demo Board Firmware
C.1 Summary Device Firmware Flowchart - LED Driver .................................... 25
C.2 Summary Device Firmware Flowchart - Li-Ion Charger ............................... 26
C.3 Summary Device Firmware Flowchart - NiMH/NiCd Charger ...................... 27
Worldwide Sales and Service .................................................................................... 28
© 2009 Microchip Technology Inc.
DS51798A-page iii
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
NOTES:
DS51798A-page iv
© 2009 Microchip Technology Inc.
MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE
REFERENCE DESIGN
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
“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.
INTRODUCTION
This chapter contains general information that will be useful to know before using the
MCP1631HV Digitally Controlled Programmable Current Source 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 MCP1631HV Digitally Controlled
Programmable Current Source Reference Design as a LED driver or a battery charger.
The manual layout is as follows:
• Chapter 1. “Product Overview” – Important information about the MCP1631HV
Digitally Controlled Programmable Current Source 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 MCP1631HV Digitally Controlled Programmable Current Source
Reference Design.
• Appendix B. “Bill Of Materials (BOM)” – Lists the parts used to build the
MCP1631HV Digitally Controlled Programmable Current Source Reference
Design.
• Appendix C. “Demo Board Firmware” – Provides general information about the
application firmware flowcharts and where the source code can be found.
© 2009 Microchip Technology Inc.
DS51798A-page 1
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
CONVENTIONS USED IN THIS GUIDE
This manual uses the following documentation conventions:
DOCUMENTATION CONVENTIONS
Description
Arial font:
Italic characters
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
#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}
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 code supplied by
user
DS51798A-page 2
Examples
File>Save
Press <Enter>, <F1>
var_name [,
var_name...]
void main (void)
{ ...
}
© 2009 Microchip Technology Inc.
Preface
RECOMMENDED READING
This user's guide describes how to use the MCP1631HV Digitally Controlled
Programmable Current Source Reference Design. Other useful documents are listed
below. The following Microchip documents are available and recommended as
supplemental reference resources.
MCP1631 Data Sheet, "High-Speed, Microcontroller-Adaptable, Pulse Width
Modulator", DS22063A
This data sheet provides detailed information regarding the MCP1631/MCP1631V,
MCP1631HV and MCP1631VHV product families.
PIC16F616/HV616 Data Sheet, "14-Pin Flash-Based, 8-Bit CMOS
Microcontrollers”, DS41288A
This data sheet provides detailed information regarding the PIC16F616 product family.
AN1137 Application Note, “Using the MCP1631 Family to Develop Low-Cost
Battery Chargers”, DS01137A.
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.
© 2009 Microchip Technology Inc.
DS51798A-page 3
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
DOCUMENT REVISION HISTORY
Revision A (May 2009)
• Initial Release of this Document.
DS51798A-page 4
© 2009 Microchip Technology Inc.
MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE
REFERENCE DESIGN
Chapter 1. Product Overview
1.1
INTRODUCTION
The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design is used to drive and dim one or more power LEDs in a series or parallel topology
(depending on the LED’s capability). The reference design may also be used to charge
one to four cell NiMH/NiCd or one to two cell Li-Ion battery packs. The board uses the
MCP1631HV high-speed analog PWM controller and PIC16F616 microcontroller to
generate the proper dimming ratio for LEDs or charge algorithm for NiMH, NiCd and
Li-Ion batteries.
The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design is used to evaluate Microchip’s MCP1631HV in a SEPIC power converter
application. The MCP1631HV Digitally Controlled Programmable Current Source
Reference Design is user programmable. Multiple user functions may be selected by
re-compiling the source code. The board can drive LEDs or charge NiMH, NiCd or
Li-Ion batteries with a maximum current of 1A. In Charger Mode, the MCP1631HV
Digitally Controlled Programmable Current Source Reference Design provides a
constant current charge (Ni-based chemistry) and constant current/constant voltage
(Li-Ion based chemistry) with preconditioning, cell temperature monitoring (for
Ni-based) and battery pack fault monitoring. In LED Driver mode, the MCP1631HV
Digitally Controlled Programmable Current Source Reference Design provides a
constant user defined current and a 10:1 dimming ratio. The dimming ratio and
maximum current can be selected before compiling the source code. The board has
LED indicators to provide multiple fault indication.
This chapter covers the following topics:
• What is the MCP1631HV Digitally Controlled Programmable Current Source
Reference Design Reference Design?
• What the MCP1631HV Digitally Controlled Programmable Current Source
Reference Design Reference Design Kit includes.
3.5V to 16V
Power Supply
+
MCP1631HV SEPIC
Programmable
Current Source
FIGURE 1-1:
© 2009 Microchip Technology Inc.
THERMISTOR
-
LED
or battery pack
+
Block Diagram.
DS51798A-page 5
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
1.2
WHAT IS THE MCP1631HV DIGITALLY CONTROLLED PROGRAMMABLE
CURRENT SOURCE REFERENCE DESIGN?
This board utilizes Microchip’s MCP1631HV-3.3 (high-speed PIC® MCU PWM
TSSOP-20, 3.3V supply version).
The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design is a complete stand-alone constant current LED power supply with a dimming
ratio of 10:1. The board is capable of delivering a maximum of 1 Amp @ 8.5W output
power. Efficiency is typically 85% at the maximum power.
TABLE 1-1:
DEFAULT OUTPUT CAPABILITY IN DRIVING LED MODE
Maximum
output current1
Dimming ratio
Maximum
Output power1
Overvoltage
protection
Thermal
shutdown2
700 mA
10:1
8.5W
9V
40°C
Note 1:
2:
Maximum output current can be modified in the source code. Absolute max is 1A
@8.5W.
For an easy start with the MCP1631HV Digitally Controlled Programmable Current
Source Reference Design Board, this option is not enabled in the compiled .hex file
which is available on the Microchip website.
The board may also be re-programmed to charge Li-Ion, NiMH, and NiCd battery
packs. The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design is capable of charging one to four NiMH/NiCd batteries connected in series or
one to two Li-Ion batteries in series. See Table 1-2 for detailed charger capabilities.
TABLE 1-2:
MULTI-CHEMISTRY CHARGER CAPABILITY
Battery Chemistry
Li-Ion
NiMH or NiCd
Note:
1 Cell
2 Cells
3 Cells
1A
500 mA
NA
4 Cells
NA
700 mA
700 mA
700 mA
700 mA
The SEPIC converter is capable of buck-boost operation. The duty cycle
may be changed in the source code to allow boost operation. Set the
“00234R1.h” header file pre-processor duty cycle definition to:
#define OSCILLATOR_DUTY_CYCLE
25
for 25% duty cycle and to allow boost operation.
The input voltage range for the reference board is 3.5V to 16V.
An input terminal block is provided to apply the input voltage to the board. An output
header with 5 pins is also provided as a means to connect the load LEDs or battery
pack and an external 10 kΩ thermistor. When used, thermistors should either be
mounted on the LED heatsink next to the LED case or internal to the MiMH/NiCd
battery pack.
A programming header compatible with the PICkitTM2 and ICD 2 programmers is on
board for updating the firmware contained in the PIC16F616. Firmware updates are
required to switch between LED, NiMH/NiCd, and Li-Ion modes of operation.
1.3
WHAT THE MCP1631HV DIGITALLY CONTROLLED PROGRAMMABLE
CURRENT SOURCE KIT INCLUDES
The MCP1631HV Digitally Controlled Programmable Current Source kit includes:
• The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design,102-00234
• Important Information “Read First”
DS51798A-page 6
© 2009 Microchip Technology Inc.
MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE
REFERENCE DESIGN
Chapter 2. Installation and Operation
2.1
INTRODUCTION
The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design demonstrates Microchip’s MCP1631HV high-speed Pulse Width Modulator
(PWM) used in LED lighting and multi-chemistry battery charger applications. When
used in conjunction with a microcontroller, the MCP1631HV will control the power
system duty cycle to provide output voltage or current regulation. A PIC16F616
microcontroller is used to provide the MCP1631HV switching frequency oscillator and
reference voltage. The MCP1631HV generates a duty cycle and provides fast
overcurrent protection based upon the feedback and current sense inputs.
MCP1631HV external signals include the input oscillator, the reference voltage, the
feedback voltage and the current sense. The MCP1631HV generates a square-wave
output signal to drive the powertrain switch. The power train used for the MCP1631HV
Digitally Controlled Programmable Current Source Reference Design is a
Single-Ended Primary Inductive Converter (SEPIC). The PIC16F616 microcontroller is
programmable, allowing the user to modify or develop their own firmware routines to
further evaluate the MCP1631HV Digitally Controlled Programmable Current Source
Reference Design in this application.
2.2
FEATURES
The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design has the following features:
•
•
•
•
•
•
•
•
•
Input Operating Voltage Range: +3.5V to +16V
Firmware default output current of 700 mA with dimming ratio 10:1 (70 mA/step)
Maximum output current of 1000 mA
Maximum output power of 8.5W
Drive one or more LEDs
Firmware for charging Li-Ion, NiMH, and NiCd batteries
ON/OFF/Dimming switch
Status and fault indication
Hardware and software overvoltage protection (OVP) set to 9.0V. The software
value can be modified in the source code to be less than 9.0V
© 2009 Microchip Technology Inc.
DS51798A-page 7
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
2.3
GETTING STARTED
The MCP1631HV Digitally Programmable Current Source Reference Design is fully
assembled and tested for driving and dimming power LEDs. At the output, one or more
LEDs can be connected in parallel or series topology. With the default firmware, the
board can drive a 700 mA load with 9V overvoltage protection. This board requires an
external voltage source within a range of +3.5V to +16V input. User supplied LED’s are
also required to evaluate the reference board. A user supplied thermistor mounted on
the LED package is needed to use the thermal shutdown feature in firmware.
Output Current (A)
0.8
700 mA Drive
0.7
0.6
0.5
350 mA Drive
0.4
0.3
0.2
0.1
0
0
2
4
6
8
10
12
14
16
Input Voltage (V)
FIGURE 2-1:
DS51798A-page 8
LED Driver Output Current vs. Input Voltage.
© 2009 Microchip Technology Inc.
Installation and Operation
The MCP1631HV Digitally Programmable Current Source Reference Design firmware
may be re-programmed with the charger profile for Li-Ion or NiMH/NiCd battery packs.
Firmware profile pre-proccessor definitions are :
• #define LION_SUPPORT DISABLED
• #define NIMH_SUPPORT DISABLED
• #define LED_DRIVER_SUPPORT ENABLED
Setting one of the profiles to ENABLED and the other two to DISABLED will select the
ENABLED profile at compile time. The re-compiled code will then perform the functions
required for the selected profile.
Figure 2-2 shows the charge profiles for a single-cell 1000 mAh Li-Ion battery pack.
Figure 2-3 shows the charge profile for a three-cell 600 mAh NiMH battery pack with
Temperature Shutdown disabled. Disabling the Temperature Shutdown is only done
one time in the lab to profile the battery pack and chemistry. The Temperature
Shutdown should always be enabled in production firmware to prevent the battery pack
from overheating during a charge cycle.
5.0
2.0
4.0
1.6
3.0
1.2
2.0
0.8
Amps
Volts
VBAT
IOUT
1.0
0.4
0.0
0.0
200
0
FIGURE 2-2:
© 2009 Microchip Technology Inc.
50
100
Time (min)
150
Li-Ion Charge Profile for 1000 mAh Cell.
DS51798A-page 9
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
I
5.0
1.0
VBAT
0.8
T/10
3.0
0.6
2.0
0.4
1.0
Amps
Volts,°C/10
4.0
0.2
IOUT
0.0
0
20
40
60
80
0.0
100
Time (min)
FIGURE 2-3:
DS51798A-page 10
NiMH Three-Cell (3.6V/600 mAh) Charged at Maximum 0.75C.
© 2009 Microchip Technology Inc.
Installation and Operation
2.3.1
Power Input and Output Connection
2.3.1.1
POWERING THE MCP1631HV DIGITALLY PROGRAMMABLE
CURRENT SOURCE REFERENCE DESIGN
1. Prepare the power supply to be connected to the input terminal block, J1. The
input voltage source should be limited to the 0V to +16V range. For nominal
operations, the recommended input voltage should be between +3.5 and +16
volts with a 12W input supply.
2. Connect the positive side of the input source (+) to pin +VIN of J1. Connect the
negative or return side (-) of the input source to pin GND of J1. Refer to
Figure 2-4.
(+) LED Anode
+VIN
GND
(+) THERMISTOR (optional)
(-) LED Cathode
(-) THERMISTOR (optional)
FIGURE 2-4:
2.3.1.2
Power Supply and Load Connections Diagram.
APPLYING A LOAD TO THE MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE REFERENCE DESIGN
1. To apply an LED load to the MCP1631HV Digitally Controlled Programmable
Current Source Reference Design, the anode of the LED should be connected
to pin 1 (+) of J2. The cathode of the LED should be connected to pin 5 (-) of J2.
The default drive current for LEDs is set to 700 mA in the supplied firmware. The
LED load which is connected to the reference board must be capable of handling
700 mA. If the LED load is not capable of handling 700 mA, then the firmware
must be re-compiled with the LED drive current set to the current capability of the
LED load being used. The minimum programmed current that the board will
generate is 10% of the programmed drive current. For the reference board
firmware which is set to 700 mA of drive current, the minimum would be 70 mA.
2. Optionally, a thermistor referenced to the (-) pin of J2 may be utilized for thermal
shutdown.
The recommended thermistor is EPCOS Inc. P/N: B57500M0103A005.
Note:
© 2009 Microchip Technology Inc.
The Thermal Shutdown is not enabled by default in the firmware. It can be
enabled by re-compiling the source code with this feature enabled. The
thermistor must be used if the board is programmed with NiMH/NiCd
charger firmware.
DS51798A-page 11
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
2.3.1.3
USING THE REFERENCE BOARD
The push button is used to switch the output ON or OFF (Standby). The first pressing
of the power button will turn on the board and drive the output at 10% of programmed
current (70 mA for the default firmware). The GREEN LED will flash with a 1 second
period, indicating that it is in normal operating mode.
The board is capable of a 10:1 dimming ratio. Each additional pressing of the power
button will increment the output drive current by 10% of the programmed drive current
up to the actual programmed drive current value.
To switch the output OFF, press and hold the push button for about 2 seconds until the
LED turns RED.
2.3.1.4
STATUS AND FAULT INDICATION
The MCP1631HV Digitally Programmable Current Source Reference Design has a
dual color (red/green) LED to indicate the status and faults. Table 2-1 shows the status
of the LEDs during various states of operating modes.
If a no load, overvoltage, or overtemperature fault condition occurs during operation,
the fault condition will be indicated by a flashing RED LED.
The RED LED will flash at a 1 Hz rate if an overtemperature condition has been
detected. An overtemperature condition will result in Thermal Shutdown.
The RED LED will flash at a 2 Hz rate if an overvoltage or missing load condition has
been detected. An overvoltage or missing load condition will result in an Overvoltage
Shutdown.
A fault condition must exist for 5 consecutive firmware sampling periods to be validated
as a hard fault.
TABLE 2-1:
STATUS OUTPUT
STATE / FAULT
DS51798A-page 12
LED Status
Standby / Charge Complete State
GREEN ON
ON (Dimming or Charging) State
GREEN Flashing
Switching to Standby State
RED ON after button press delay
Over Temperature Fault
RED Flashing (1 Hertz)
Over Voltage Fault
RED Flashing (2 Hertz)
Charge Timeout Fault
RED Flashing (2 Hertz)
Calibration Complete State
YELLOW (both LEDs ON)
© 2009 Microchip Technology Inc.
Installation and Operation
2.3.1.5
MCP1631 PROGRAMMABLE CURRENT SOURCE AS BATTERY
CHARGER
The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design reference board is provided with the LED driver firmware programmed into the
U2 microcontroller.
The reference board package also has compiled firmware *.hex files included for
Li-Ion and NiMH/NiCd battery packs. There are two versions of charger firmware. One
is for Li-Ion cells (00234R1-LiIon_Charger.hex) and the other is for NiCd/NIMH cells
(00234R1-NiMH_NiCd_Charger.hex).
2.3.1.5.1
How to Connect and Charge a Battery with the MCP1631HV Digitally
Controlled Programmable Current Source Reference Design
To charge a battery pack with the MCP1631HV Digitally Controlled Programmable
Current Source Reference Design, the positive connector of the battery should be
connected to J2-1 (+). The negative terminal of the battery should be connected to
J2-5 (-).
A thermistor referenced to J2-5 (-) should be used for thermal shutdown if the battery
chemistry is NiMH/NiCd. To evaluate a NiMH/NiCd battery charger pack that does not
have an internal thermistor, it is recommended to attach an EPCOS Inc.
P/N: B57500M0103A005 thermistor onto one of the cells of the battery pack. This
thermistor should be connected to J2-4 (+) and J2-5 (-).
Note:
The maximum charge current for the Li-Ion chemistry is programmed and
limited at 1A for a single cell (4.2V) or 500 mA for two cells in series
topology. The pre-programmed maximum charge current for NiMH/NiCd
chemistry is 700 mA.
For evaluation, all charge parameters can be modified in source code. See the header
file 00234R1.h for the pre-processor definitions.
2.3.1.5.2
Charge Profiles
The pre-programmed parameters for the battery charge profiles are:
• Li-Ion
- Qualification: Precharge at 200 mA for VCELL < 3.0V
- Constant Current: 1A for 1 Cell, 0.5A for 2 Cells
- Constant Voltage: 4.20V (this value should be calibrated for better accuracy,
see Section 2.3.1.5.4 “Calibrating the Output Voltage for the Li-Ion
Chemistry Profile”)
- Charge Termination: 70 mA for 1 Cell and 2 Cells
- Overvoltage Detection: Once detected, attempts to restart the charge cycle 5
times. If overvoltage is still present, the charge cycle is aborted and the RED
LED is flashed.
• NiMH/NiCd
- Qualification: Precharge at 140 mA for VCELL < 0.9V
- Constant Current: 700 mA for 1 Cell to 4 Cell
- Terminate Fast Charge for -dV/dT or +dT/dt
- Top off Charge Current: 35 mA
Top off Charge Time: 1 hour
- Overvoltage Detection: Once detected, attempts to restart the charge cycle 5
times. If overvoltage is still present, the charge cycle is aborted and the RED
LED is flashed.
© 2009 Microchip Technology Inc.
DS51798A-page 13
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
2.3.1.5.3
How the MCP1631HV Digitally Controlled Programmable Current Source
Reference Design Operates in Charger Mode
Follow the instructions in Section 2.3.1.5.1 “How to Connect and Charge a Battery
with the MCP1631HV Digitally Controlled Programmable Current Source
Reference Design” to connect a battery pack at the board. In the Standby (OFF) state,
the GREEN LED will be lit. Push the S1 button to start the charge profile and turn on
the output. The GREEN LED will flash.
If any fault conditions are detected during charging, the RED LED will flash and the
output will automatically turn off. See Table 2-1 to identify the nature of the fault. When
a charge cycle successfully completes, the GREEN LED will be turned ON and the
output will be turned off. The system will stay in a Standby (OFF) state until the next
button push.
At any moment, the charging can be stopped by pressing and holding the push button
until the RED LED turns on.
The default calibration value for the Li-Ion pack is 4.2V. For better accuracy, the output
voltage should be calibrated before starting a charge cycle. See
Section 2.3.1.5.4 “Calibrating the Output Voltage for the Li-Ion Chemistry Profile”
for instructions.
2.3.1.5.4
Calibrating the Output Voltage for the Li-Ion Chemistry Profile
Prior to the first Li-Ion charging cycle, it is recommended to calibrate the charger
termination voltage for better accuracy. Connect a 12V power supply to the J1
connector. Select another power supply for the calibration voltage and set it to the
desired termination voltage between 3.9V and 4.20V. Connect the calibration power
supply to the J2 connector. Connect the positive lead to J2-1 and the negative lead to
J2-5.
1. Press S1 to turn on the board.
2. Wait for the GREEN LED to light. If it does not light, check for faults.
3. When the GREEN LED is lit, press and hold down S1 for 2 seconds until the
YELLOW LED (both green and red LEDs) is lit. The YELLOW status indicator
signals the calibration is complete.
4. The calibration power supply can now be removed from the J2 output connector.
DS51798A-page 14
© 2009 Microchip Technology Inc.
Installation and Operation
2.3.1.6
VIEW THE STATE OF MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE REFERENCE DESIGN
The MCP1631HV Digitally Controlled Programmable Current Source Reference
Design is able to show, using an oscilloscope, the system state. To use this feature,
connect the scope probe to test point TP1. Testpoint TP1 is output pin U2-8 of the
PIC16F616 microcontroller. There are nine status waveforms listed below. A pulse
stream of one to nine 10 µs pulses are generated at TP1 test point every one second
interval. The pulse stream indicates the current state of the system software. Note that
the first two states may complete immediately and thus may be difficult to capture on a
non-storage scope.
•
•
•
•
•
•
•
•
•
1 pulse - output power is switched ON
2 pulses - qualification charging
3 pulses - charging - NiMH / NiCd constant current mode
4 pulses - charging - NiMH / NiCd top off current mode
5 pulses - charging - Li-Ion constant current mode
6 pulses - charging - Li-Ion constant voltage mode
7 pulses - dimming - LED constant current mode
8 pulses - fault - overvoltage protection state
9 pulses - output power switched OFF (Standby)
2.3.1.7
PROGRAMMING THE PIC16F616 MICROCONTROLLER
To evaluate the board, the firmware package provides 3 hex files for the LED driver,
Li-Ion Battery Charger, and NiMH/NiCd Battery Charger. The board is factory
programmed with the LED driver firmware for 700 mA maximum current and 10:1
dimming (~70 mA/step). All parameters may be changed in firmware to the desired
value according to the output capability. The source code is commented extensively
and helps the user to define the board.
The header file, 00234R1.h, contains the pre-processor definitions which define the
system. The user may modify the definitions to change specific system parameters to
meet design goals.
mikroElektronika’s mikroC compiler was used to compile the source code and create
the hex files for downloading to the reference board. The mikroC compiler is available
at http://www.mikroe.com. The compiler is not included with the reference board kit.
Header J3 is provided for in-system circuit programming. A PICkitTM2 programmer may
be connected to J3 to program the reference board.
Connect the PICkitTM2 programmer to J3.
Start the PICkitTM2 software.
Set Device to PIC16F616.
Erase the device.
Select “File” then “Import Hex” from the menu. Browse to the desired *.hex
firmware file to download.
6. Write the file.
7. The status window should indicate success or failure of the download.
1.
2.
3.
4.
5.
© 2009 Microchip Technology Inc.
DS51798A-page 15
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
NOTES:
DS51798A-page 16
© 2009 Microchip Technology Inc.
MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE
REFERENCE DESIGN
Appendix A. Schematic and Layouts
A.1
INTRODUCTION
This appendix contains the following schematics and layouts for the MCP1631HV
Digitally Controlled Programmable Current Source Reference Design:
•
•
•
•
Board Schematic
Board – Top Solder Pads and Silk-Screen Layers
Board – Top Copper Layer
Board – Bottom Copper Layer
© 2009 Microchip Technology Inc.
DS51798A-page 17
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
BOARD – SCHEMATIC
M
A.2
1
2
3
4
5
6
7
8
2
1
3
DS51798A-page 18
© 2009 Microchip Technology Inc.
Schematic and Layouts
A.3
BOARD – TOP SOLDER PADS AND SILK-SCREEN LAYERS
© 2009 Microchip Technology Inc.
DS51798A-page 19
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
A.4
BOARD – TOP COPPER LAYER
DS51798A-page 20
© 2009 Microchip Technology Inc.
Schematic and Layouts
A.5
BOARD – BOTTOM COPPER LAYER
© 2009 Microchip Technology Inc.
DS51798A-page 21
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
NOTES:
DS51798A-page 22
© 2009 Microchip Technology Inc.
MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE
REFERENCE DESIGN
Appendix B. Bill Of Materials (BOM)
TABLE B-1:
Qty
BILL OF MATERIALS
Reference
Description
Manufacturer
Part Number
3
C1, C2, C4
CAP CERAMIC 10UF 25V X5R
1206
Panasonic® - ECG
ECJ-3YB1E106M
1
C10, C12
CAP 1500PF 50V CERM CHIP
0805
Panasonic - ECG
ECJ-2VB1H152K
1
C3
CAP CER 2.2UF 25V X7R 0805
Murata Electronics® North
America
GRM21BR71E225KA7
3L
1
C5
CAP .1UF 16V CERAMIC X7R
0805
Panasonic - ECG
ECJ-2VB1C104K
8
C6, C8 ,C9, C13, CAP CER 1.0UF 25V X7R 0805
C14, C15, C16,
C17
Taiyo Yuden
TMK212BJ105KG-TR
2
C7, C11
CAP 22PF 50V CERM CHIP 0805
SMD
Panasonic - ECG
ECJ-2VC1H220J
1
D1
DIODE SCHOTTKY 30V 3A SMA
ON Semiconductor
MBRA340T3G
2
D2
LED Dual RED/GREEN Clear
SOT-23
Lumex® Opto/Components
Inc.
SSL-LX15IGC-RP-TR
1
J2
CONN HEADER 5POS .100 VERT
TIN FRICTION LOCK
Molex® Electronics
22-23-2051
1
J3
CONN HEADER 5POS .100 VERT
TIN
Molex Electronics
22-03-2051
1
L1
SMD-Shielded Power Transformers Wurth Elektronik
(SEPIC) WE-DD
744877100
1
PCB
RoHS Compliant Bare PCB,
Digitally Controlled Programmable
Current Source Reference Design
Microchip Technology Inc.
104-00234
1
Q1
MOSFET N-CH 30V 5.9A 8-SOIC
Vishay® / Siliconix
SI4346DY-T1-E3
Semiconductor®
1
Q2
MOSFET N-CH 60V 280MA
SOT-23
Fairchild
2
R1, R19
RES 10.0K OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF1002V
1
R12
RES 10.0 OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF10R0V
2
R14, R20
RES 49.9K OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF4992V
1
R15
RES 107K OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF1073V
1
R16
RES 20.0K OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF2002V
2
R17, R18
RES 40.2K OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF4022V
Note 1:
NDS7002A
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.
© 2009 Microchip Technology Inc.
DS51798A-page 23
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
TABLE B-1:
Qty
BILL OF MATERIALS (CONTINUED)
Reference
Description
Manufacturer
Part Number
1
R21
RES 3.92K OHM 1/8W 1% 0805
SMD
1
R24
RES 0.0 OHM 1/8W 5% 0805 SMD Panasonic - ECG
ERJ-6GEY0R00V
1
R4
RES 39.2K OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF3922V
2
R6, R7
RES 1.00K OHM 1/8W 1% 0805
SMD
Panasonic - ECG
ERJ-6ENF1001V
1
U1
MCP1631HV 3.3V 20 Pin TSSOP
High Speed PWM
Microchip Technology Inc.
MCP1631HV-330E/ST
1
U2
IC PIC MCU 14-Pin Flash-Based,
8-Bit CMOS MCU
Microchip Technology Inc.
PIC16F616-I/SL
Note 1:
Panasonic - ECG
ERJ-6ENF3921V
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.
DS51798A-page 24
© 2009 Microchip Technology Inc.
MCP1631HV DIGITALLY CONTROLLED
PROGRAMMABLE CURRENT SOURCE
REFERENCE DESIGN
Appendix C. Demo Board Firmware
C.1
SUMMARY DEVICE FIRMWARE FLOWCHART - LED DRIVER
For the latest version of the MCP1631HV Digitally Controlled Programmable Current
Source Reference Design LED Driver firmware, visit our web site at
www.microchip.com.
START
Initialize: Processor, Parameters
(ILEDmin = 70 mA, ILEDmax = 700 mA),
Timers, Sample ADC()
No
S1 Pressed?
Yes
ILEDmin
Yes
OVP Test
VOUT> 9.0V?
No
Shutdown
No
S1 Pressed?
Yes
No
OVP
time retries
>5
S1 pressed >
= 2s?
Yes
No
Increment IREF(70 mA)
Yes
Shutdown
Fault
END
FIGURE C-1:
© 2009 Microchip Technology Inc.
Summary LED Driver Flowchart.
DS51798A-page 25
Demo Board Firmware
C.2
SUMMARY DEVICE FIRMWARE FLOWCHART - LI-ION CHARGER
For the latest version of the MCP1631HV Digitally Controlled Programmable Current
Source Reference Design Li-Ion Charger firmware, visit our web site at
www.microchip.com.
START
Yes
S1 pressed
> 2s ?
Initialize: Processor,
Parameters, Timers;
SampleADC()
Yes
No
OVP Test
VBATT
>4.4V/Cell?
S1 pressed?
No
Yes
No
No
Precondition
Current Mode
I=200 mA
Calibrate LiIon()
VBATT
> 3.0V/Cell?
Yes
Constant
Current Mode
Yes
MAX = 1.0A 1 Cell
MAX = 0.5A 2 Cell
VBATT<4.2V?
No
Constant Voltage
Mode
No
Charge Timer
=0?
No V
BATT>4.2V?
Yes
Yes
Decrement IBATT
Shutdown
No
IBATT
<= 70 mA?
Yes
Shutdown
(charge complete)
Shutdown
OVP
No
time retries
>5
Yes
END
FIGURE C-2:
© 2009 Microchip Technology Inc.
Fault
Summary Li-Ion Charger Profile Flowchart.
DS51798A-page 26
Demo Board Firmware
C.3
SUMMARY DEVICE FIRMWARE FLOWCHART - NIMH/NICD CHARGER
For the latest version of the MCP1631HV Digitally Controlled Programmable Current
Source Reference Design NiMH/NiCd Charger firmware, visit our web site at
www.microchip.com.
START
Initialize: Processor,
Parameters, Timers;
SampleADC()
S1 pressed?
No
Yes
Yes
ChargeTimer=0?
Shutdown
No
Yes
Is VBATT
> 1.8V / Cell?
No
Cell
temp > 40oC?
Shutdown
Yes
No
No
Is VBATT
> 0.9V / Cell?
OVP
time retries
>5
Precondition
No Current Mode
Yes
Fast charge Mode
ICHARGE = 700 mA
Yes
Fault
dV/dt<-10mV
dT/dt>1.5C
No
Yes
TopOff Charge Mode
Charge Timer = 1h
Yes
No
Cell Temp
> 40°C?
No
OVP?
No
OTP
No
time retries
> 5?
Yes
ChargeTimer=0?
Yes
Yes
Fault
OTP
time retries
> 5?
No
Yes
Fault
Shutdown
END
FIGURE C-3:
© 2009 Microchip Technology Inc.
Summary NiMH/NiCd Charger Profile Flowchart.
DS51798A-page 27
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03/26/09
DS51798A-page 28
© 2009 Microchip Technology Inc.