On 3/9/06, Michael Rigby-Jones wrote: > > > >-----Original Message----- > >From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] > >Sent: 09 March 2006 12:32 > >To: Microcontroller discussion list - Public. > >Subject: Re: [EE] LVTTL Schmitt trigger non-inverting buffer - > >do they existintiny packages? > > > > > >On 3/9/06, Michael Rigby-Jones wrote: > >> > >> > >> >-----Original Message----- > >> >From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] > >> >Sent: 09 March 2006 05:32 > >> >To: Microcontroller discussion list - Public. > >> >Subject: Re: [EE] LVTTL Schmitt trigger non-inverting buffer - do > >> >they existin tiny packages? > >> > > >> > > >> >On 3/8/06, Michael Rigby-Jones > >> >wrote: > >> >> Help! > >> >> > >> >> Requirements: > >> >> > >> >> Supply voltage 3.3v > >> >> Input thresholds LVTTL (0.8v/2.0v) > >> >> Output thresholds CMOS (driving an AVR) > >> >> Schmitt Trigger > >> >> Smallest package possible e.g. Philips Pico-logic or TI's > >> >> NanoStar/NanoFree die-with-solder-bumps style would be perfect. > >> >> > >> >> I've been scouring various manufacturers web sites and nothing I > >> >> can see comes close, in particular I can't find a Schmitt trigger > >> >> device with true LVTTL compliant inputs. Do they exist? > >> > > >> >http://focus.ti.com/docs/prod/folders/print/sn74auc1g17.html > >> > >> Thanks Vasile, but that's 2.7v maximum supply. I need to go up to > >> 3.3v +5% > > > >You can't, you need a 2V input requirement and a 3.3V output > >requirement. Use a 2V to 2.7V supply device with an open drain > >up to 3.3V. I had this problem too and never found such a gate > >(except the buffer level converter with many gates). > > No, I need guarantee LVTTL input thresholds which are 0.8v and 2.0v for the maximum Logic 0 threshold and the minimum Logic 1 threshold. The actual input voltage swing could be a maximum of 0-3.3 volts. http://focus.ti.com/docs/prod/folders/print/sn74aup1g17.html For a trigger schmitd, there are different thresold levels than to a normal LVTTL gate. And notice the LVTTL could be also supplied at 3.0V. So your customer must know exactly what he/she want. greetings, Vasile -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist