Super Regulator, collecting the facts

[Fred Dieckmann]

I thought you were paralelling references for noise reduction which I have seen done somewhere with build out resistors for each to isolate them. You have 6 different footprints for three different part outlines for two different polarities of references? Man I feel sorry for the guy trying to build one of these..... Isn't that pretty confusing for some one trying to figure out how to build one of these, or God forbid two, one of each polarity.

[jackinnj]

Originally posted by Fred Dieckmann
I thought you were paralelling references for noise reduction which I have seen done somewhere with build out resistors for each to isolate them. You have 6 different footprints for three different part outlines for two different polarities of references? Man I feel sorry for the guy trying to build one of these..... Isn't that pretty confusing for some one trying to figure out how to build one of these, or God forbid two, one of each polarity.

QEX had an article using several of the Thaler VRE305 Precision References in parallel. These are 0.01% acuracy, 0.6ppm drift. Who needs an Eppley Cell ? Unfortunately you have to get them directly from Thaler.

[WaltJ]

I would like to ask that my name *not be* associated with the numerous "new" regulator circuits discussed in this thread. I fact, I think the thread should be renamed, to something like "new regulator".

I take no responsibility for anything here (or elsewhere) so long as it lacks my signature.

Walt Jung

[peranders]

Originally posted by Fred Dieckmann
I thought you were paralelling references for noise reduction which I have seen done somewhere with build out resistors for each to isolate them. You have 6 different footprints for three different part outlines for two different polarities of references? Man I feel sorry for the guy trying to build one of these..... Isn't that pretty confusing for some one trying to figure out how to build one of these, or God forbid two, one of each polarity.

If someone makes this pcb, myself or somebody else, I think it's pretty convenient to be able to choose from many references. A normal intelligent person gather where the part should be in a matter of seconds and if there is a text the person can even read this.

[johnferrier]

Originally posted by peranders

If someone makes this pcb, myself or somebody else, I think it's pretty convenient to be able to choose from many references. A normal intelligent person gather where the part should be in a matter of seconds and if there is a text the person can even read this.

I agree with you.


JF

[jackinnj]

if you're looking to model the power transistor, the MJD44H11 is electrically similar to the D44H11, (same as to the complementary device also) and www.onsemi.com has SPICE2, Sabre and PSpice models. (Sorry, they are copyright, property of On-Semi and you'll have to download yourself.)

[janneman]

On the " Jung regulator - Didden PCB layout" note that the gnd plane was purposefully omitted over some of the more (capacitively) sensitive circuitry. At the time, it seemed to me the best way to avoid making possible oscillatory tendencies worse. Would I make a different layout now, with the hindsight of 8 years of experience and other opamps availble? Yes, in some details. Not in the general grounding and remote sense arrangement. And I would probably leave out the gnd plane, since almost all circuit nodes are low impedance enough to be insensitive to capacitive and RFI interference.

Jan Didden

[peranders]

Jan, isn't low impedance nodes insensitive to stray caps? Anyway, Fred thinks that the groundplane pcb form ALW is very good and when was he wrong? Ok, I have removed groundplane on my MOSFET-QRO power amp inspired of AN-4 from National and I got a slightly better step response but this was a high speed, high impedance node (emitters of a input stage).

From what I can see on bad pictures I believe that you have some ground plane on your pcb's, not totally covering the whole pcb.

You mention also that sheilding with metal can be a good thing when there is oscillation problems.

According to Walt J it's also wise to trim or determine the forbidden range of decoupling caps at the output, small caps or big but not in between. Thing is only to know the suitable values.

EDIT: Reading your post again I'm not sure what mean. Is grounplane good, bad or good if they are made with finesse?

[Fred Dieckmann]

'From what I can see on bad pictures I believe that you have some ground plane on your pcb's, not totally covering the whole pcb."

What PCBs? I have never laid out a PCB for the Super Op Amp Power Supply Under Development Series regulator. I don't know that a circuit this small with single point grounding requires a groundplane. Don't connect to capacitor cans to ground! I was kidding and trying to make the point that parts are subject to RFI as well as PCB traces. Try the PCB layout both ways and tell us if it measures and/or sounds different.

[janneman]

I DID say that the low-impedance nodes are insensitive. Read my post if necessary. And indeed, there is a (partial) gdn screen on my original layout. But again, please reread my post for my current thoughts on that. I do agree with Fred (after 8 years of more experience with these circuits) that the screen can probably be omitted without adverse effects. I think you are smart enough to realise that the answer on your question is screen good or bad is: depends.

And the quote on gnd cap cans is not mine, sorry.

The issue of output caps has been beaten to death sufficiently on this forum. Bottom line: very good caps with low ESR and high Q can cause oscillations. Stay with the reasonably good electrolytics (ESR above a few 10ths of an Ohm) and there will be stability in your regulators.

Fred: He refers to a PCB layout of mine, not yours. Turn down your pacemaker a few clicks.

jan Didden