Digilent 410-297P-KIT - Manual (Page 6)

ChipKIT MX3 Board Reference Manual
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 6 of 25
• Use the “Configure.Select Device …” menu to select the PIC32MX320F128H
• Use the “Programmer.Select Programmer” menu to select the “PICkit3” or other hardware programming tool
being used.
• Use the “File Import…” dialog box to navigate to and select the boot loader programming downloaded from
the Digilent web site. The file name will be something like: chipKIT_Bootloader_MX3.hex
• Use the “Programmer.Program” command to program all memories on the device.
1.3 Additional Reference Documentation
For additional information about the ChipKIT MX3 board and the use and operation of the PIC32MX320F128H
microcontroller, refer to the following documents in addition to this reference manual.
The ChipKIT MX3 Schematic, available on the ChipKIT MX3 product page on the Digilent web site:
www.digilentinc.com
The PIC32MX3XX/4XX Family Data Sheet and the PIC32MX Family Reference Manual available from the Microchip
web site: www.microchip.com
Additional reference material for the MPIDE system is included in the MPIDE software download, and on-line in
the chipKIT wiki. Help with questions and problems using the board with the MPIDE software can also be obtained
in the chipKIT forums:
www.chipKIT.net/install (software download)
www.chipKIT.net
www.chipKIT.org/forum
2 Power Supply
The ChipKIT MX3 is designed to be powered either from USB or from an external power supply. There is an
automatic switchover circuit that causes the external supply to be used if both supplies are present.
The power supply section uses two voltage regulators. The first regulates the external voltage to 5V to power the
VCC5V0 bus. The second regulates the VCC5V0 bus to 3.3V to provide power to the VCC3V3 bus that powers the
PIC32 microcontroller.
The 5V voltage regulator, IC2, is normally an NCP1117. The board is designed to be able to also use an LM1117, but
the NCP1117 is the part normally used. The NCP1117 is rated for an output current of 1A (the LM1117 is rated for
800mA). The dropout voltage of the NCP1117 is a maximum of 1.2V at the rated output current (1.3V for the
LM1117). There is a reverse polarity protection diode in the external power supply circuit. Considering the diode
drop plus the forward drop across the regulator, the minimum input voltage to the regulator should be 7V to
produce a reliable 5V output. The absolute maximum input voltage of both the NCP1117 and the LM1117 is 20V.
The recommended maximum operating voltage is 15V. For input voltages above 9V, the regulator will get
extremely hot when drawing high currents. Both the NCP1117 and the LM1117 have output short circuit
protection and internal thermal protection and will shut down automatically to prevent damage.
The 3.3V regulator, IC3, is a Microchip MCP1725. This regulator is rated for a maximum output current of 500mA.
The absolute maximum input voltage for the MCP1725 is 6V. This regulator has internal short circuit protection
and thermal protection. It will get noticeably warm when the current consumed by the VCC3V3 bus is close to the
500mA maximum.