I am using a solderless bread to prototype an analog sense -> 8 bit digital circuit.

  • It's messy
  • Has Hi gain sensing opamps
  • sensitive POTS

I have 20mV of noise everywhere, even when I am connecting GND to GND at a different locations... All of my ICs have decoupling caps. Putting more caps on the rails has no noticeable effect.

I assumed this is just from breadboards being terrible.

My question is could the DC-DC converter be the source of this noise? If so I need to have a linear regulator power the analog electronics.

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    \$\begingroup\$ Yes but you need to search for my answers with better probing techniques, low ESR caps, and twisted pair q&a’s \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Sep 24 '18 at 13:30
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    \$\begingroup\$ I'd suggest putting up a circuit diagram,along with a part number and link to the datasheet for the DC to DC converter. I also suggest carefully reading that data sheet, and looking for traps -- for example, some DCDC converters have a minimum load, and/or specific instructions for an output tank cap. \$\endgroup\$ – Scott Seidman Sep 24 '18 at 13:32
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    \$\begingroup\$ If you have 20mV noise everywhere, I'd suggest testing the osciloscope, if it works properly \$\endgroup\$ – Alexander von Wernherr Sep 24 '18 at 13:33
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    \$\begingroup\$ A picture of your breadboard would also be useful \$\endgroup\$ – crj11 Sep 24 '18 at 13:57
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    \$\begingroup\$ Have you looked at the specs for your DC-DC converter? 20mV ripple may be normal. \$\endgroup\$ – evildemonic Sep 24 '18 at 15:28

Sorry guys, it was the scope...

It wasn't obvious because when I directly connected the 2 probe ends I got a clean 0v DC... However, adding jumper wire created the noise.

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