Okay found the prescaler in a local store (scale factor 64) "U664" made by telefunken. But telefunken seems to be take over by some other company very hard to find some specs of the IC. Is there somebody who does? Also looked at mouser.com but it's hard to order the NEC ic's named here in holland. Regards, Aart. ----- Original Message ----- From: "Sean H. Breheny" To: Sent: Thursday, May 17, 2001 7:33 AM Subject: Re: [OT]: Frequentie Counter > You can even make this switching between prescaled and non-prescaled > automatic. Always try the prescaled input first. If you count a frequency > too low to require the prescaler, then switch to the non-prescaled input. > The PIC can do this and can also adjust the number it displays(adding a > scale factor of 100 or whatever your prescaler does) as well as the gate > period (interval over which you count pulses for each reading). > > You can buy prescaler chips which are good up to a few GHz for only a few > dollars a piece from Mouser > > http://www.mouser.com I think they are made by NEC and are under the MMIC > (Microwave Modular(?) Integrated Circuit) section. > > The only difficult part then is making your PCB layout for the prescaler > adequate. Depending on the amplitude of the signals you intend to measure, > you may be able to get away with just keeping the traces from the connector > to the IC very short, and using surface mount decoupling caps for the IC. > > Sean > > At 06:22 AM 5/17/01 +0100, you wrote: > >The URL's you provided appear to be offline. > > > >If you have a design for a 40MHz counter then add a "Divide by 100" > >prescaler and 2 inputs, one <40MHz the other >40MHz. > > > >Regards > >Chris Carr > > > >-- > >http://www.piclist.com hint: PICList Posts must start with ONE topic: > >[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics