Yes, I agree, I'm going to remove U2, it serves no purpose. Secondly, I do
understand a transimpedance amplifier, as seen in stage one, and I'm sorry
for drawing an extra wire to ground, but once removed as in the
updated schematic
<https://wiki.duke.edu/download/attachments/10715668/PulseLCD.bmp>I don't
believe there are large problems with the transimpedance amplifier.

On Thu, Feb 19, 2009 at 11:17 AM, Olin Lathrop <olin_piclist@embedinc.com>wrote:

> PAUL James wrote:
> > Looks like u2 is a low pass filter that is AC coupled to the next stage.
>
> Yes, but it has a gain of one and isn't performing any impedence buffering
> either.  The filter functions could be just passive parts between the two
> other opamp stages.
>
>
> ********************************************************************
> Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
> (978) 742-9014.  Gold level PIC consultants since 2000.
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist