Thanks for the help, your suggestions have worked. Still seems kind of strange that I'm getting 4v from an input...hehehe brandon irwin --- David Huisman wrote: >Brandon, > >I missed the earlier posts but looking at this... What do you mean the ADC >has a reference output of about 4V ? >If you are measuring at Vref, this pin is an input and would need to be tied >to either your reference voltage or VCC. > >In the data sheet they recommend you connect an external reference of 2.5V >+/- 2%. (AD780) > >Also, I note the IC is available in 3V and 5V versions, is your supply >correct for the version ? > >Best Regards > >David Huisman > > > >-----Original Message----- >From: pic microcontroller discussion list >[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Tim Hamel >Sent: Friday, 16 November 2001 12:13 >To: PICLIST@MITVMA.MIT.EDU >Subject: Re: [EE] AD7829 problems > > >In a message dated 11/15/01 3:15:19 PM Pacific Standard Time, >brandon@E-HA.COM writes: > > >> This AD7829 has a reference output of about 4v instead of 2.5 +/- 2% like >> specs say. I plug it in without any connections whatsoever (except -Chip >> Select) and it has this output. >> >> If anyone has experience in these I'de like to know why its doing this. >> Could it be burnt out? It seems to do conversions ok, except for the >> horribly off reference. >> >> Thanks. >> >> -brandon irwin >> > > >Well, according to the datasheet, either you can supply Vref or use the >internal Vref. They also mention decoupling the Vref pin to AGND via a .1uF >cap. They also the same for the Vmid pin. See if that helps. > >-Tim > >-- >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. _____________________________________________________________ Get your free email here at http://www.e-ha.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body