DESIGNCYCLETHE
ADVANCED TECHNIQUES FOR DESIGN ENGINEERS
■ BY FRED EADY
BRINGING A USB-TO-UART
PROTOCOL CONVERTER TO LIFE
Did you know that Microchip offers a USB 2.0 to UART protocol converter?
It’s called the MCP2200. The MCP2200 is not totally limited to performing
USB-to-serial conversion duty. Outfitted in 7. 5 mm (.300 inches) SOIC
packaging, the MCP2200 resembles a PIC in form and function by providing
an octet of GPIO (General-Purpose Input/Output) pins and EEPROM. In this
edition of Design Cycle, you and I are going to scratch-design a plug-in USB
converter module based on the MCP2200. After we bring the MCP2200
hardware to life, we’ll configure the MCP2200 and put it to work in front of
the UART of a USB-challenged microcontroller.
MCP2200 ORIENTATION
In addition to SOIC, the MCP2200 can be had in QFN
and SSOP packages. If you’re a hobbyist, chances are you
don’t have the necessary soldering tools to lay down tiny
leadless QFN packages. The chances are also slim as to a
hobbyist’s toolability to accurately place and hand-solder
SSOP parts. So, I’ve chosen to develop our MCP2200
design around the larger and easier to handle 20-pin SOIC
package which can be easily placed and hand-soldered.
■ FIGURE 1. It looks like a PIC, kinda acts like a PIC,
but it ain’t officially a PIC. At least the datasheet says
it ain’t one.
58
July 2010
