PIC28 Breadboard Adapter

Schematic 

     Breadboard adapter for PIC processors in 28 pin packages: The PIC 28 pin QFN package is fanned out to a 100 mil pin pitch by 500 mil row spacing to fit into a standard solderless breadboard.  The pinout of the adapter is laid out the match the equivalent through hole component. Most PIC18 processors in a 28 pin option will fit this adapter.

     In addition to the processor, a Mini-B USB interface is included that provides and RS232 communication channel, level shifted to connect to PICs powered over their entire VDD range, from 1.2 to 5.5V.

     These adapters include everything on the schematic except the PIC processor and the 10uF Vdd-Core capacitor (C7) which only used on a few parts that operate with an internal core regulator that operates at a different voltage than the I/O. A zero ohm jumper resistor (R3) is included that connects the USB VBUS to the processor VDD allowing the breadboard to be directly powered from the USB interface. This resistor may be removed to allow processor operation at voltages other than 5V or to isolate VBUS from the breadboard power.

     For in circuit programming, the ICSP signals and power pins are connected to a 6 pin, 2mm pitch surface pad connector. A 2mm header can be soldered the board or a pogo programming adapter can be used.