Stealing one of my old projects. I will set jinks onto you pal Why not go for 1GHz using a prescaler types SP4731 or SP4633 Plessey SDA4212 Siemens U664B Telefunken SAB6456 Phillips Find the devices first then the data sheets then build. I may have part of this drawn in my cadd files not on this machine. Regards Art ----- Original Message ----- From: Ole Petter Rxnningen To: Sent: Tuesday, October 31, 2000 8:19 PM Subject: [EE]: Frequency counter > Hi, all > > > I'm trying to design a frequency counter.. I'm not using the Weeder counter > on PIClist.com for two reasons: > 1. I have a 100Mhz scope, so I'd like a 100Mhz counter > 2. My scope outputs 25mV/Div, so the sensitivity of 800mV @ 50Mhz isn't good > enough. > > What I am currently trying to figure out is how to make a Schmitt trigger > with levels at 25 and 50 mV. I have seen a couple of examples, but none with > so small values.. In addition, I am worried that the high frequency will > cause problems. Does anyone have pointers/hints? > > I was thinking of using a 311 comparator hooked up to a 74F269 8-bit counter > after the trigger, and then steal the code for the Weeder.. ;o) > > Thanks! > OP > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.