Function Generator Kit

Nuxie and SparkFun worked together to rehash Nuxie's Function Generator Kit. This kit is based around the XR-2206 monolithic function generator IC, and can produce sine, triangle, and 5V square waves with frequencies ranging from 15Hz to over 500kHz.

A selector switch allows you to pick either a sine or triangle wave to be output to the 'WAVE' pin. The amplitude of this wave can be adjusted from about 1V up to either 7V (triangle) or 5V (sine). A square wave is also emitted by the XR-2206, and run a couple times through an inverter to even the wave out. This wave will have a maximum of 5V, so it can be interfaced with a microcontroller or other TTL-level devices.

There are two selectable frequency ranges as well. When the 'FREQ' switch is set to Low, the frequency can be adjusted from 15Hz to 4.5kHz. In the High position, the frequency can go from 3kHz to about 650kHz. Two pots are used to adjust the frequency, providing both coarse and fine adjustments. The XR-2206 can emit frequencies from 0.01Hz up to 1MHz, if you need a frequency that this kit doesn't provide, we've broken out a couple extra resistors (R8, and R9), to give you the ability to customize your kit.

The XR-2206 requires a relatively high voltage for normal operation, this kit has it running at 12V. This means you'll need at least ~14VDC (no greater than 35V though!) to get the kit running at the optimal 12V. If you just want to use the 5V square wave output though, you could probably cheat and use a 9V wall adapter; we've used this in a few tests, and it hasn't caused us any problems.

Assembly is straight-forward and can be done with a simple multimeter for testing resistor and potentiometer values. The board is labeled clearly and should be good for beginners.

Lastly, if you'd like a quick and easy display of the frequency. This kit can be mated directly with our Frequency Counter Kit!

Documents:

• Schematic
• Eagle Files
• Datasheet XR-2206