a.down
Newbie level 1
Good afternoon. I'm designing a low-noise analog front end. Nothing fancy, i am shooting for a 0.5uV baseline noise after digitization with a +/-5V dynamic range. All within the capabilities of the latest ADCs like the LTC-2508 IF i can provide a quiet enough environment. The application needs to be battery powered, which i figured would probably help my cause, eliminate any switching regulators and stick to really low noise LDOs. I'm chasing some noise around and i noticed that if i measure the terminals of my lead-acid battery directly with a tek TBS2000 scope i get alot of noise. This isnt an isolated scope, so the noise floor already looks like 10mVrms across its 70MHz bandwidth, but with the probe on the battery i get almost 30mVrms across 70MHz. That works out to something like 3.5 uV/sqrt(Hz), i was under the impression the chemical noise of an SLA was about 1000x quieter than that.
Anyone else stumble across something similar?
Thanks kindly,
-Alexander
Anyone else stumble across something similar?
Thanks kindly,
-Alexander