I have used Cygnal parts in a number of designs and found no real issues regarding the use of the parts in designs. I have experienced NO more susceptibility of these parts over similar parts from other manufacturers. If you use careful consideration of what you are doing and apply good design practices you will be able to produce sucessful designs with ease.

Some things to consider....

1) One design I worked on used a 128K flash Cygnal part at 22.1184 MHz as a controller on a military radio. The controller operates typically within 3 feet of the radio antenna which can transmit at up to 55 Watts of RF on almost any frequency band you can think of. Had no problems of susceptibility.

2) Had another design where a part at 25 MHz emitted (just the opposite of susceptibility) a bit too much RF to satisfy the needs of the FCC/CE/MIL emissions test requirements. That was fixed by covering the processor on the circuit board with a small square of aluminized mylar that was cut with a tab on the corner that was then put under a mounting screw to ground it to the chassis. The opposite side of the mylar was prepared with 3M 467 type acrylic adhesive to stick the shield to the processor TQFP-100 package top.

3) Every one of the Cygnal evaluation boards that I have seen and used are built with two layer boards. I find that they run reliably even when cobbled up with prototype appendages consisting of interface boards, cables, flying wires!!

4) Do not wait for a 5V version of a Cygnal part. It will not happen. I can understand the hesitation that can occur the first time a designer is faced with veering off from the old familiar 5 volt trail. But I have found that once you commit yourself to doing an all 3.3V style of design you will wonder why you thought it was such a big deal!! [ As an aside it is nice being able to use a multi-channel oscilloscope at 1 volt / cm instead of at 2 volt / cm. You can do this nicely when the logic signals swing 0 -> 3.3. :-) ]

Michael Karas