ADC help

Archiver

I am trying to interface my BS2 with TI's tlc2541 ADC.
http://www.ti.com/sc/docs/products/analog/tlv2541.html
I don't quite understand the function of the SCLK pin. Is this an
external input, or a reference that the converter provides? If it is
external, do I need to provide some sort of oscillator or can I just
toggle one pin high and low?
Finally, does anyone know of any sites out there that discuss ADC
design? I haven't had much luck finding anything useful yet...

Thanks
Chris
www.MesoSystems.com

Archiver

Chris, www.MesoSystems.com, wrote:
> I am trying to interface my BS2 with TI's tlc2541 ADC.
> http://www.ti.com/sc/docs/products/analog/tlv2541.html
> I don't quite understand the function of the SCLK pin. Is this an
> external input, or a reference that the converter provides? If it is
> external, do I need to provide some sort of oscillator or can I just
> toggle one pin high and low?


SCLK ("serial clock") is provided by the BS2 SERIN command:

low ADcs ' select chip on CS\
shiftin sdo,sclk,msbpre,[noparse][[/noparse]result\12] ' get result, 12 bits
high ADcs

The shiftin command provides exactly 12 clock pulses and the tlc2541 data
appears on its sdo line in 12 steps in sychk.

> Finally, does anyone know of any sites out there that discuss ADC
> design? I haven't had much luck finding anything useful yet...

Most manufacturers provide application notes that go in detail into the
particular technology that they use in their chips. Search their sites.
If you want a tutorial that starts from the basics with the Stamp, check
out <http://www.stampsinclass.com/downloads.htm> and scroll down to "Basic
Analog and Digital Experiments".

-- Tracy Allen
Electronically Monitored Ecosystems
http://www.emesystems.com