LOL! What was I thinking?

[DZ]

Hey Anthony, thanks! That was actually with the prototype, which aparently is still sitting on Bill's desk at pangolin... I was hoping it would get passed around a bit for testing, however no ones schedule seems to mesh.

[drlava]

I see low-pass filtering happening.. what all can this board do?

[DZ]

It's sort of a hybrid circuit built around both the "ready for anything" circuit and the simple Sallen Key filter circuit from Pangolin's website. The input accepts differential or single ended. In fact, with the breakout board I make, you can select either differential or single ended, in changing the setting on the breakout board, the output of the color board is completely unaffected. The circuit also has an offset and gain stage to setup the lower and upper limit on the modulation signal. The protection built in prevents anything higher than +5.1V or lower than -.3V to pass thru the board. It also features a jumper to change how the delaying action works.

Link to Pangolin's site regarding the color delay stuff: http://www.pangolin.com/resguide03d.htm

[drlava]

Ah, sounds good. color delay, right! What is the common mode rejection ratio of the differential to single ended converter section? I.E. if you put a 1V sine wave on both +X and -X, what is the peak-to-peak signal on the output?

[ljk]

Looking good DZ I am excited to put it into my scanner project.

[DZ]

The specs on the op-amp used is 86dB as typical. I haven't measured it though.

[drlava]

When you hand-build diff amps the limiting factor is the precision of the resistors, assuming the math is correct Often times this results in much lower CMRR than the op amp rating.

[DZ]

Ah, that is true. I will run a test on a couple eventually, right now I only have the one working, still need to do a ton of assembling on the rest of them.

[300EVIL]

Very Nice! I can't wait to get one!