Flash Crystal
Frequency Synthesizer
Have you ever needed a clean, stable RF source for that special project? It might have been a low power transmitter to use as a test source for antenna work. Maybe it was a local oscillator for that new VHF transverter project. Maybe it was for portable or battery powered operation. A crystal oscillator would suffice for some applications, but who can wait 6 weeks for a custom crystal order? Maybe you needed to select up to 10 different channels. Ordering 10 custom crystals would be expensive. Maybe you needed to lock several different sources to a common frequency standard. A laboratory style synthesized signal generator would work, but they are big and expensive, and not very portable. Flash Crystal to the rescue! What's a Flash Crystal? Well, just as a flash microcontroller is field reprogrammable, the Flash Crystal is a small, field reprogrammable frequency synthesizer that acts like a programmable crystal oscillator. The Flash Crystal can even be locked to an external frequency standard (e.g.: 10.000 MHz) or use its own internal crystal oscillator as the reference. The Flash Crystal can store and remember up to 10 frequencies that are addressed using a tiny rotary DIP switch located on the board. Programming the Flash Crystal is easy. Just connect the Flash Crystal to the serial port of any PC running HyperTerminal (included with Windows), and the Flash Crystal will communicate with you. Type in the frequency control information, and the Flash Crystal will obey. Use the "U" and "D" keyboard commands to tune the Flash Crystal "Up" or "Down" in steps. The frequency of the Flash Crystal can be changed 1 million times without affecting its ability to remember. Once the desired frequencies have been programmed, no PC is needed to use the Flash Crystal. Just apply power, and the Flash Crystal will wake up and start generating the frequency presently selected by the DIP switch. Change the DIP switch setting at any time to select a different stored frequency. The Flash Crystal puts out approximately 5 milliwatts (+7 dBm) of clean, stable RF power. The Flash Crystal packs a lot of capability into a small (less than 2" x 2"), low cost package.
If you would like to know more about the Flash Crystal then read the Flash Crystal manual (687 KB). This is an Adobe Acrobat file. (Latest update 06/11/05)
There is much more information coming with pictures and application suggestions.