Datasheet Jargon Translation Required (2023 Update)

Or "figure 27" as they also show it as. Bottom of page 16 anyway.

No use trying to help you.

Ri on that opamp includes a dynamic microphone!

Please stop trying to educate it then. This is a creature who still thinks resistors must have leads. Fully Neanderthal...

Poles are jargon.

Poles come from complex analysis representing zeroes in the denominator of a transfer function. Zeroes in the numerator are just called zeros. Electronic engineers have adopted the language of mathematicians here.

The name makes sense too. If you plot the function, it looks like tent poles.

Jeroen Belleman

I'd never really thought about it like that. First ran into them in complex analysis and contour integration methods for solving various diverse physics problems more elegantly via Cauchy's Residue Theorem.

Introduction for anyone interested in the gory details here:

A dynamic mic driving an inverting opamp gets much more interesting. Kind of a tent village.

Sounds like the kind of excitement that is best avoided by using the non-inverting input and living with whatever tiny increase in distortion results. No change to compensation.

Exactly. Inverting has all sorts of interesting issues.

Mic loading. Noise. DC offset.

But you already have! As has Speff and a couple of other worthy individuals. This is one tiny project I'd rather others didn't design for me. Spoils all the fun! :-D

If you won't post your schematic, then we can't have any fun!

The LaPlace/pole/zero thing was academic formalism in the pre-computer age. I don't do that stuff any more... just Spice it.

That fussy stuff was linear anyhow. The world isn't linear.

My profs loved that sort of math. I don't think any of them actually designed anything.

S-params and Smith charts are arguably similar relics of the graph paper and slide-rule days.

Are you unable to view the diagram at all? Remember those old programs we used to use on this group that generated ASCII art representations of schematics? Crude but effective and in the days when we had nothing else - Invaluable.

So... what's the issue with the diagram I linked to?

The opamp data sheet? It isn't a microphone amplifier.

But never mind.

Of course you don't. Getting your head around the academic formalism lets you understand what's going on, and you don't do that.

Most of us have noticed. The linear bits are easier to understand and manipulate, so they get more attention.

Of course, since John Larkin doesn't actually understand what "design" involves, this isn't a useful observation.

S-parameters have been around for a while, as have Smith charts. Visual representation of what's going on do help people develop an understanding of the processes involved, but John Larkin is happy to rely on Darwinian evolution to get him to circuits that work well enough to sell, even if he doesn't understand quite how they work.

A computer is merely an bigger, faster more precise slide-rule and graph paper is a slower form of visual display. Chart recorders were the original data loggers.

It just shows how to use the chip as a simple inverting amplifier without having it oscillate like crazy due to stray capacitance at the input. Which part of make R1*C1=R2*C2 do you not understand?

The real practical difficulty is matching your dynamic microphone to the "ideal" amplifier for lowest possible distortion and maximum signal.

John is asking to see that part - not the gain block after it.

There are all sorts of subtelties about a dynamic mic amp. The inverting opamp is a bad start.