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I'm making my own variable bench power supply with the LM338 (driven with negative rail of -1.25 for 0v out) and I want to use an Arduino to control the output voltage. I would like to use the X9C102 digipots but...

They're each rated for 5v max Vcc (I plan to use 6 for 30v output max [5v/chip]) Because I want to use six in series I want to know if this is possible to do, given that digipots are weird 'n' that.

Thank you

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digipots can be fed from a variety of precision sources but instead you'd prefer to also use the power division for feeding the adjust pins if possible but you may encounter unexpected noise or oscillations at some point so be careful to have a test model running before daisychaining the pots.

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  • \$\begingroup\$ Indeed, I neglected to realise that to control every single pot it would need 5v signals relative to the specific chip's ground, which is over complicated and unnesasary. I've read elsewhere that you can filter the PWM of the Arduino, buffer it and use that instead (of course I'd need to amplify and subtract 1.25 from that.) \$\endgroup\$ – Sean Jones Jan 3 '19 at 14:40
  • \$\begingroup\$ don't worry it's not a competition. sometimes you can join different technologies and sometimes you can't. LM117 and digipots don't look a very efficient setups to me. power LM338 straight from arduino lirearized pwm and eventually get some feedback that would work. \$\endgroup\$ – sphericsf Jan 3 '19 at 16:56

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