Fred Kerr <[email protected]> wrote: > [-- multipart/alternative, encoding 7bit, 70 lines --] > > [-- text/plain, encoding 7bit, charset: UTF-8, 27 lines --] > > Hello all, > > How should the 1.8V ADC (and other) pins be protected? One method may be > the attached, voltage divider of 1M/100K then limited by two diodes in > series. (Not tested, just paper design currently.) > > I'd like to explore other methods or suggestions. I have some old or > obsolete parts that I can use with info from data sheets. But it'd be nice > to go "modern". > > What about VCO to optoisolator? (Think of hostile / automotive > applications.) > > Suggestions: Circuits, books, URLs? > I have used some very low power op-amps which I have actually powered from the 1.8 volt ADC reference voltage. This means they *can't* drive the ADC inputs to more than 1.8 volts.
They are wired up as simple voltage followers so the output voltage exactly follows the input voltage. The op-amps are TI LM10s. It's been working for a year or more now and the BBB is all working still. The LM10 op-amps can handle quite large input voltages without damage. -- Chris Green ยท -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/037t5f-mrl.ln1%40esprimo.zbmc.eu. For more options, visit https://groups.google.com/d/optout.
