Michel, what an amazing eye for detail! You are right. I never noticed that bias restriction in the datasheet. As you see, I have taken quite a few shortcuts to make the whole analog circuit power from a 5V supply with bare minimum part count. I should spend some time correcting this ASAP, as the MAX509 may not be very happy at the moment. Surprisingly, in 2 years and several clocks nothing has failed and there seem to be no odd symptoms.
Your other ideas regarding the controller are really invaluable, I only hope to spare time to try some of them soon! Aaron On 2012-09-08 11:26, Michel wrote: > I am just reading the datasheets of the MAX509 as I thought if you can > use 0V for REFA and +5V for AGND, you wouldn't have to invert the > voltages of OUTA and OUTB. > > Then, I came across this note in the Absolute Maximum ratings: > > "Do not bias AGND more than +1V above DGND, or more than 2.5V below > DGND" > > In your circuit you bias it 2.5V above DGND. Are you sure you can do > this?? > > Michel -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
