EEVblog #1328 - uCurrent OPA189 Measurements

Part 3 of designing a better uCurrent series.
Measuring the noise and consumption of the OPA189 compared to the MAX4239 using a dynamic signal analyser and an oscilloscope.

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#uCurrent #Design #Measurement

[jrb_sland]

05:20 offset & noise amplitudes may wander a bit during the first few minutes after power-on. I've done part-per-billion high-precision frequency measurements [flicker-free at 28 bits in a 32-bit resolution counter] where I need to wait ~ 20 minutes for the reference oscillator to settle down. Patience is a virtue - set up the test, power it on, and head for the coffee machine. Thick wall shielding box wrapped in a bath towel is another virtue, not only for EMI rejection but to add thermal mass. Gotta love these high-resolution measurements - everything is a thermometer if you peer deeply enough into the swamp.

[flymypg]

Three 20 minute eposiodes means it's the microamp hour!

[Dave]

This is more proof that TI still makes the best parts in the industry, analog or digital. And when TI gives a spec for a product it is a real spec. Not an idealized specification like most other manufacturers give (whenever possible) for their parts.
PS: The in depth looks at this type of thing are great! Thanks for the look at how you do this type of testing.

[innopriest]

Definitely enjoying the "series" and look forward to more.

[NoOneYouKnow]

Using the uCurrent to measure the power supply current of the uCurrent is a very pleasing recursion, lol

[Krmpfpks]

Thank you so much. I don't need a lower noise floor uCurrent, but that doesn't keep me from wanting one badly. As soon it's out, I'll upgrade. If they werent so expensive I'ld update one myself just for fun.

[RomanDvoryadkin]

You can put stack of two CR2016 instead of one CR2032 and get 6V without changing battery slot.

[TheHibener]

Sorry that i don't comment all your Videos. I learned so much with your channel 😀. Greetings from Austria 🇦🇹

[WarpRadio]

the box! (thats EXACTLY what I NEEDED for back in my pirate radio days.. and now I see one 30 years too late! oh, well... )

[OneBiOzZ]

I used the OPA189 in a project recently, it also handles saturation very very well with some input resistors (never tested it without)
at least in my testing of 3 for a few minutes

[thomascornelissen]

Hi Dave, regarding the high frequencies spikes for the OPA189 opamp. If you vary the analyser sampling frequency you could rule out an aliasing effect.

[ats]

At low frequencies, a steel box will provide much better shielding...

[johnsonlam]

It's good to enjoy a better performance mod, satisfying.

[lambertax]

I like this edited videos. Shorter and complete. 👍

[wouter]

Opa is Dutch for grandpa. Seriously love your work Dave big thums

[AdrianRumpold]

What happened to the silkscreen at the bottom right @2:07, Mr. "I vi I L. J n-s" ;)?

[Iceteavanill]

3:28 -> Is that a updated version of the 121GW

[samfedorka]

Any plans to compare with the ADA4528 that was mentioned in the first video? Would be interesting to see how it stacks up.

[PHamster]

So Dave, when do you want floating measurements instead of it being ground?

[Wistigri]

I would have tried to screw the enclosure cover. It might have significantly increased the shielding.