Microchip Technology MA180021 User Manual
© 2007 Microchip Technology Inc.
DS51678A-page 19
PIC18F87J50 FS USB
PLUG-IN MODULE
USER’S GUIDE
Appendix A. PIC18F87J50 FS USB Plug-In Module Schematics
A.1
SCHEMATICS
The PIC18F87J50 FS USB Plug-In Module schematics are shown in Figure A-1 and
Figure A-2. By default, the PIM ships from the factory with the PIC18F87J50
pre-installed in location U1. The PIC18F87J50 is the superset part in the device family,
and is therefore, a good starting point for developing USB applications that will
eventually use one of the other devices in the device family.
However, the pads of U1 have been designed to accommodate any of the products in
the PIC18F87J50 family of microcontrollers, both the 80-pin TQFP and 64-pin TQFP.
For example, if the PIC18F87J50 is carefully desoldered using hot air, and the pads are
cleaned using solder wick, it is possible to install the 64-pin TQFP PIC18F65J50 in its
place. This is possible since the pin pitch is the same between the 64-pin and 80-pin
TQFP packages, and the functionality is the same for pins which share the same loca-
tions between the two packages. Effectively, the 80-pin TQFP pads of U1 overlap with
the standard 64-pin TQFP pads.
The board revision number can be found etched into the copper on the bottom side of
the PCB underneath the programming header. The board revision number is the last
number in the line and is located inside the rectangular box.
Figure A-2. By default, the PIM ships from the factory with the PIC18F87J50
pre-installed in location U1. The PIC18F87J50 is the superset part in the device family,
and is therefore, a good starting point for developing USB applications that will
eventually use one of the other devices in the device family.
However, the pads of U1 have been designed to accommodate any of the products in
the PIC18F87J50 family of microcontrollers, both the 80-pin TQFP and 64-pin TQFP.
For example, if the PIC18F87J50 is carefully desoldered using hot air, and the pads are
cleaned using solder wick, it is possible to install the 64-pin TQFP PIC18F65J50 in its
place. This is possible since the pin pitch is the same between the 64-pin and 80-pin
TQFP packages, and the functionality is the same for pins which share the same loca-
tions between the two packages. Effectively, the 80-pin TQFP pads of U1 overlap with
the standard 64-pin TQFP pads.
The board revision number can be found etched into the copper on the bottom side of
the PCB underneath the programming header. The board revision number is the last
number in the line and is located inside the rectangular box.