I tend to agree with REB on the EMC things, especially when I was attending the EMC seminars or reading some application notes. "The real world is noisy and we have to compensate for it". However it is always easy said than done. Engineering design are also always kind of trade-off between good design practise and other issues like cost and space constraint. A chip does played a part in this EMC aka black magic. The colleague told me that they always put reset IC with Atmel and still often have problems with current injection (IEC61000-4-6) test (the MCU reset or just go mad). Some of our product have to comply with NAMUR NE21 standard for the chemical industry and it is quite stringent in term of EMC. I consider our Germany R&D teams to be very strong in analog design and follow good design practise. In terms of software, I think they are also quite good as well. They were not facing so much problems before using Atmel. Some of our product only need to comply with EN60947-5-2 standard for proximity sensors and things are not that bad and they use Atmel a lot due to the low cost and popularity of Atmel in Europe. They do have issues with EMC too. In this aspect, PICs are better. We do have some EMC problems with the new PIC 16F device (/MCLR pin reset). Maybe die shrinking is to blame. In the production, we also have more problems with the ISP with ATmel MCUs (89C51 and the AVR) than PICs (ICSP) and maybe that is a separate issue. That being said, our purchasing department is having major issues with Microchip in terms of pricing and delivery policy. Maybe that is the problem when they become No 1. So we do hope Atmel parts to be better and better. :( Xiaofan >Date: Thu, 25 Nov 2004 09:02:20 -0500 >From: "Roy E. Burrage" > >> >>> >>> Then I talked to the another colleague in another division, he >>> told me that we have major issues with Atmel due to EMC and other >>> performance problem. So for high reliability product, they are >>> now considering Microchip in the low end and Renesas in the high end. >> >> I would like to know more about this, I've not hit any issues of this >> nature. >As would I. As an analog person who was forced into this digital >jun..er stuff, it seems that the only times I have had issues of this >sort were when I didn't use good design practices in the first place; >e.g. at 0300 you discover that the 100 pieces of a zero crossing triac >driver was actually 92, so you stuff a non zero crossing version into >the hole during test and then have intermittent craziness when a motor >starts. But this would also be an issue in almost any circuit. Atmel >also has a good app note addressing EMC which is pretty good, albeit >common sense. > >EMC/RFI/EMI problems often get blamed on a chip when they are actually a >result of design practices in my experience. It doesn't make any >difference if the system is PLC, microcontroller, discrete logic, or any >other type we might want to name, the real world is noisy and we have to >compensate for it. > >REB _______________________________________________ http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist