I had trouble with the ECS on a 67c74 at 16 MHz. When I talked with them, they said that as long as it worked with their inverter circuit (published on their datasheet, as I recall), the resonator is fine. The problem is with the chip. Not much help! So, I ended up with murata. Their website in Japan has a search engine that will give you a part number for the resonator to use with a particular chip. I've been using one of their resonators with internal capacitors in several products. We've probably shipped a few thousand units now with almost no problems. The almost is because in one product I decided I'd run wide traces the fraction of an inch from the 16c74 to the resonator (this is maybe 0.150 inch). Microchip did a die shrink from the 16c74a to the 16c74b and our board stopped working! All the other products did fine! We had to go back to 16c74a for this product while we use the B on everything else. I've revised the board and we'll start using the revised board soon... Anyway, murata seems pretty good to me! None of the other resonator companies I talked with seemed to know what a microcontroller was. Harold On Tue, 21 Mar 2000 21:37:57 -0500 Marius Bratrein writes: > Does anyone have experience using a ceramic resonator at clock > speeds > greater than 16 mhz? Can anyone tell me which resonators will work? > I > have tried an ECS ZTT series 20mhz resonator, but as far as I can > tell, > the PIC does not have enough gain to drive it. Thanks ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj.