Current mirror question: hybrid mirror (PNP/NPN)? - Page 1
Forum section: electronics / projects

author: Analog Kid
author_rank: Super Contributor
timestamp: October 29, 2024, 06:03:09 am
content: Probly over my head here, but here goes:Let's say a guy would want a current mirror that would reflect one current used as a source onto another current used as a sink: would this work?I ask this somewhat naively; my guess would be that the Vbelevels might be off because of the reverse polarity of the Qs, but I really have no idea. Again, the idea is that the transistor on the left (PNP) would source current to something, while its partner on the right (NPN) would sink the identical current.

author: moffy
author_rank: Super Contributor
timestamp: October 29, 2024, 06:13:02 am
content: You have effectively two diodes in series with a power supply across them, not good.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 29, 2024, 07:10:00 am
content: Yikes. OK, scratch that idea.So how would a guy accomplish this?

author: Someone
author_rank: Super Contributor
timestamp: October 29, 2024, 10:51:54 am
content: Quote from: Analog Kid on October 29, 2024, 07:10:00 amPut the current source and current sink in series.....

author: Manul
author_rank: Super Contributor
timestamp: October 29, 2024, 10:53:58 am
content: Quote from: Analog Kid on October 29, 2024, 07:10:00 amWhy not use two current mirrors, one NPN and one PNP? One of them can set the current for another one. So it will translate current sink into current source or vice versa.

author: tggzzz
author_rank: Super Contributor
timestamp: October 29, 2024, 11:56:28 am
content: Quote from: Analog Kid on October 29, 2024, 06:03:09 amThis kind of question can be quickly answered by a Spice simulation. Draw your schematic, select components from library, select type of simulation, run simulation.Key points about any simulations: results depend on quality of schematic and component models, single numerical answers rather than general analytical results.There are many versions of Spice available, including LTSpice, MicroCap, QSpice, TINA.

author: magic
author_rank: Super Contributor
timestamp: October 29, 2024, 12:52:48 pm
content: SPCIE will have no problem with this circuit...The only question is whether it will be kA or MA flowing through those transistors. Any bets?

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2024, 04:06:28 pm
content: When sketching a simple circuit idea such as this, start by adding the expected voltages at each node and currents through each branch, with simplified assumptions such asVbe= 0.7 V and beta = 100.If it seems reasonable, then try Spice to get a better answer.

author: TimFox
author_rank: Super Contributor
timestamp: October 29, 2024, 04:22:37 pm
content: Quote from: Manul on October 29, 2024, 10:53:58 amThis is a practical approach: note that the direction of current flow in a NPN/NPN or PNP/PNP current mirror.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 30, 2024, 04:07:41 am
content: Turns out the problem I'm dealing with here is a topological one, meaning the problem of how to tie in a current mirror to a certain connection point in a circuit.So: here are the two forms of the classic current mirror using 2 BJTs:The first one, the PNP mirror, sources current to circuitry below the mirror; the other one (NPN) sinks current from above.My problem: I need to source the Isetcurrent to a component, but then have the Imirrorcurrent sunk from another part of the circuit (hence my "hybrid" in the topic).According to one suggestion here I could couple two current mirrors together, one as source, the other as sink. I'm thinking (but aren't sure) that this arrangement would do that:(I'm assuming that the current of the 2nd mirror would be set by the current sourced by the first one, so no set resistor would be required.)Now all these schemes so far are using the current mirror as a 3-terminal device, with either a common V+ (PNP/source) or ground (NPN/sink) terminal.But what if we could construct a current mirror as a 4-terminal device, so that one side could be used as a source and the other as a sink (or vice versa):Is this possible?I don't really like the 2 cascaded mirror plan, as it would seem to introduce even more error into the equation. But if this is the only way to accomplish this, then I guess so be it.One thing: discretes only. No ICs!

author: tggzzz
author_rank: Super Contributor
timestamp: October 30, 2024, 10:02:29 am
content: You need ICs, since you need closely matched devices.You can also use MOSFETs, e.g. see the applications inhttps://aldinc.com/pdf/ALD1106.pdfAdvanced Linear Devices have some interesting deviceshttp://www.aldinc.com/ald_mosfetarrays.phpYou mention "I don't really like the 2 cascaded mirror plan, as it would seem to introduce even more error into the equation.", but don't quantify the allowable errors. It might be relevant for you to specify the currents, voltages, and required tolerance.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 30, 2024, 10:31:49 am
content: First things first. I'm trying to get an answer to the topological question here, namely the "4-terminal" idea. If you have anything to say about that it would be appreciated.Accuracy is a few items down the list here.

author: tggzzz
author_rank: Super Contributor
timestamp: October 30, 2024, 10:36:02 am
content: Quote from: Analog Kid on October 30, 2024, 10:31:49 amYoumentioned accuracy.Try simulating your circuit with a Spice. You will quickly get some answers to your questions, and will learn a lot.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 30, 2024, 10:47:02 am
content: Quote from: tggzzz on October 30, 2024, 10:36:02 amI'd try simulating it (with LTSpice, which I've used), but I can't simulate what I have no idea how to construct, hence my questions here, hoping those who know a lot more than I do might be helpful. I thought that was the idea of forums like this one. Maybe I'm wrong about that.

author: tggzzz
author_rank: Super Contributor
timestamp: October 30, 2024, 11:12:59 am
content: Quote from: Analog Kid on October 30, 2024, 10:47:02 amYou have schematics that can be entered into a Spice and simulated.You can even use ideal components: Spice has voltage-controlled-current-sources and current-controlled-current-source components as used in some of the pictures you supply.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 30, 2024, 11:27:06 am
content: Quote from: tggzzz on October 30, 2024, 11:12:59 amNot for my notional 4-terminal device I don't.Or haven't you been reading what I wrote?Sheesh.

author: tggzzz
author_rank: Super Contributor
timestamp: October 30, 2024, 11:32:57 am
content: Quote from: Analog Kid on October 30, 2024, 11:27:06 amSpice contains all the components for this picture of yours:

author: magic
author_rank: Super Contributor
timestamp: October 30, 2024, 05:35:49 pm
content: Somebody already gave you the solution: connect the reference current sink in series between the load and ground.And if you can't do that because the sum of voltage drops across the generator and the load exceeds your supply voltage, then how on earth could any floating transistor circuit work between them?

author: Alex Nikitin
author_rank: Super Contributor
timestamp: October 30, 2024, 06:45:50 pm
content: Like that? Only as an illustration of a topology. R2 can be replaced by an active device to control both currents at the same time.CheersAlex

author: Analog Kid
author_rank: Super Contributor
timestamp: October 30, 2024, 11:44:36 pm
content: Quote from: tggzzz on October 30, 2024, 11:32:57 amNo, it doesn't: what about the link between the two sides, whatever components are needed to make the right-side current track the left side?Look: if you're really trying to help here, then why don't you just give me a circuit--you know, with components, a schematic, doesn't matter if it's drawn on a napkin--that will perform this function, as I'm sure you're capable of, OK? Otherwise, maybe just keep silent and let others help here.

author: tggzzz
author_rank: Super Contributor
timestamp: October 30, 2024, 11:53:08 pm
content: Quote from: Analog Kid on October 30, 2024, 11:44:36 pmIt is your circuit; you tell us!It sounds like you are thinking of "current controlled current sources", in which case seehttps://www.eecg.utoronto.ca/~kphang/teaching/spice/part2.html#6.8

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 12:07:49 am
content: Yes, I think it's fair to say I'm looking for just that, a current-controlled current source.Any chance I can get a schematic rather than a bunch of Spice parameters? That would bemuchmore useful to me at this point.

author: tggzzz
author_rank: Super Contributor
timestamp: October 31, 2024, 12:19:10 am
content: Quote from: Analog Kid on October 31, 2024, 12:07:49 amSpice source code is an ASCII netlist, originally on punched cards. Draw a Spice schematic. You will see that it is converted into an ASCII netlist; originally the conversion was done by hand. A schematic is merely syntactic sugar.Try LTSpice, and all will become clear.It isn't difficult, but it will be avaluablelearning experience for you. Yes, that requiresyouto do some work, but you will gain from that.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 12:25:16 am
content: Somehow I knew you'd come back with that.What's with your insistence that I use Spice to model this?Like I said before: you're not my Electronics 203 professor.Thanks but no thanks; I don't roll that way (entering code into Spice).

author: tggzzz
author_rank: Super Contributor
timestamp: October 31, 2024, 12:37:32 am
content: Quote from: Analog Kid on October 31, 2024, 12:25:16 amWhy? "Give a man a fish and you have fed him for a day, but teach a man to fish and you have fed him for his lifetime" - old proverb."You can lead a horse to water, but you can't make it drink" - another old proverb.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 12:45:51 am
content: Quote from: TurboTom on October 31, 2024, 12:34:33 amThanks, but I already covered that inthis post(under "Cascaded Current Mirrors"). But thanks for confirming my guess at the circuit.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 01:10:33 am
content: Quote from: Alex Nikitin on October 30, 2024, 06:45:50 pmThat is an interesting topology. However, I don't see how that answers any of my questions above. So far as I can tell it's just a variation on the PNP current-sourcing mirror I posted.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 08:34:08 pm
content: Continuing: if someone would be so kind as to help a guy out here, a guy who obviously doesn't know as much as you do, that would be just great.The question remains: is it possible to implement something like this:perhaps something like this?Of course I could probably do this instead:but it'd be nice if there were something simpler (=lower parts count) and perhaps better.If you think I'm full of it pursuing this scheme, please let me know.The idea is to somehow transfer the Isetcurrent from the source side to the sink side. The problem, I think, is in matching VBElevels from the left side to the right. I think. (I'm still a n00b when it comes to designing transistor circuits).

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 08:44:57 pm
content: The lower circuit can be made to work.The mystery box in your middle circuit is the “central column” of the bottom circuit.However, the “intersecting circles” symbol used for Imirror1and 2 is the standard symbol for a current source, not an ammeter (the analog of a battery symbol for a voltage source).You can replace each with a wire, or use a resistor to reduce collector dissipation (if needed).The accuracy of the mirroring depends directly on theVbematch of each pair separately.As before, you can improve that with appropriate series resistors in each emitter.(Edit: replaced “each collector” with “each emitter”.)

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 08:51:36 pm
content: Quote from: TimFox on October 31, 2024, 08:44:57 pmOK; but wouldn't that end up just being the bottom circuit itself, since the "central column" is those two transistors PNP & NPN)? or is there some other way to implement that?That sounds like an endorsement of the "cascaded" circuit. Maybe you can clarify?QuoteThanks. In the interest of accurate representation I'll correct that; don't want to mislead anyone here. (Note to self!)

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 08:54:06 pm
content: Yes, that’s why the bottom circuit can work.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 09:06:45 pm
content: D'you like this better?Any objection to the diagonal line? Supposed to indicate a meter needle, not anything variable.Apparently some hypersensitive individuals object to the use of this ... certainly don't want to offend anyone's sensibilities here ...

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 09:10:11 pm
content: I think KiCad uses that symbol for meters. I often see just a circle with the unit (V or A) and polarity indication. (I’ve never seen a real meter with a needle that long—must mean just the movement and not the case.)

author: tggzzz
author_rank: Super Contributor
timestamp: October 31, 2024, 09:16:50 pm
content: Quote from: Analog Kid on October 31, 2024, 09:06:45 pmSensibility is irrelevant.If you want to communicate, you need to have a shared vocabulary and grammar. Lewis Carroll famously highlighted what happens if you don't do that with Humpty Dumpty and his "glory".You have drawn a voltage source with a letter "A" inside it and a line across it.Here's the first example I blundered across of how to show voltages and currents (not sources) in a schematicinIMHO Vid should be a single-ended arrow to indicate which is positive.

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 09:22:01 pm
content: Anyway, if you want to reduce the number of transistors, you can replace each of the two with collector shorted to base with a simple diode (e.g., 1N4148), but to get accurate results you will need the four resistors I keep mentioning.

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 09:33:24 pm
content: Quote from: tggzzz on October 31, 2024, 09:16:50 pmA quick Google search gives only circles (with A or V inside) as meters.It gets messy with sources: different tabulations show circles with A or V and +,- inside the circle as sources.The double circle or equilateral triangle (showing direction) always means current source.

author: tggzzz
author_rank: Super Contributor
timestamp: October 31, 2024, 09:42:10 pm
content: Quote from: TimFox on October 31, 2024, 09:33:24 pmGurgle search for what?If there is a physical meter in the circuitmeasuringcurrent perhaps, but not whenindicatingthe current being discussed.

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 09:46:55 pm
content: A Google search for “schematic symbol for voltmeter”.It is common to show a meter symbol to indicate a virtual meter to show a virtual measurement, since it’s equivalent to installing an ideal meter there (0resistance for ammeter, infinite for voltmeter).

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 09:49:11 pm
content: Quote from: tggzzz on October 31, 2024, 09:16:50 pmI would use the single-ended arrow only for current flow, as in that drawing. Voltage floweth not.The double-ended arrow in your drawing shows a potential difference; I have seen that used with a flat line segment at the “reference” end instead of a point.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 09:51:37 pm
content: Quote from: TimFox on October 31, 2024, 08:44:57 pmWait, what? Don't you mean resistors in eachemitter? That's where I thought those "equalizing" Rs went.

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 09:56:29 pm
content: Quote from: Analog Kid on October 31, 2024, 09:51:37 pmOops—I went back and corrected the post.

author: tggzzz
author_rank: Super Contributor
timestamp: October 31, 2024, 10:01:33 pm
content: Quote from: TimFox on October 31, 2024, 09:49:11 pmVoltages is across, not throughIt is a directed value, as is current. Betchya didn't know thatA flat line at one end indicates polarity unambiguously, so that would be fine.I don't think I've ever drawn it like that, and I would often indicate current with an arrowhead on/"in" the wire.

author: Analog Kid
author_rank: Super Contributor
timestamp: October 31, 2024, 10:13:22 pm
content: OK, latest iteration:"Equalizing" emitter resistors added. Ammeter symbol altered so as not to offend those with delicate sensibilities. ("Yeah, what's that stupid line with an arrow doing there?")Any objections? Everybody happy?And who knows: it might even work ...Time to simulate this (IRL on a breadboard).Oh, BTW, @TimFox, I decided to leave the transistors-connected-as-diodes rather than replacing them, as there's a better chance of a match between the two devices. Agree? I mean, a jelly-bean transistor is about as simple a part as a 1N4148.

author: TimFox
author_rank: Super Contributor
timestamp: October 31, 2024, 10:16:27 pm
content: You can replace Rset and the meter with a current source, if you want.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 31, 2024, 11:54:54 pm
content: Quote from: Analog Kid on October 31, 2024, 08:34:08 pmThe simplest circuit for that, is a wire. Imirror2 = Iset !Quote from: Analog Kid on October 31, 2024, 08:34:08 pmYou can buy matched pair parts easily these days, which are the fundamental building blocks of current mirrors.Quote from: Analog Kid on October 31, 2024, 08:34:08 pm? That is two packages, hard to be simpler than that.Emitter resistors are somewhat optional, when using matched pairs.Quote from: Analog KidNot only should you keep transistors, you should usematched pair packaged parts. Easy to find in 2024 in a choice of currents and voltages.

author: Analog Kid
author_rank: Super Contributor
timestamp: November 01, 2024, 12:14:57 am
content: Quote from: PCB.Wiz on October 31, 2024, 11:54:54 pmYou mean like this?I had that originally, but someone said that it would just burn up because I had two diodes across the power supply.??

author: TimFox
author_rank: Super Contributor
timestamp: November 01, 2024, 12:17:20 am
content: That is only two forward-biased diodes in series across the power supply: recipe for smoke.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: November 01, 2024, 12:33:03 am
content: Quote from: Analog Kid on November 01, 2024, 12:14:57 amNo, your drawing show Iset as a current source - perhaps that was a mistake ?If you start with iSet, and want to duplicate that as Imirror2 = iSet, they are already the same direction so no double mirror is needed. A simple wire is enough.

author: Analog Kid
author_rank: Super Contributor
timestamp: November 01, 2024, 01:35:17 am
content: Quote from: PCB.Wiz on November 01, 2024, 12:33:03 amSorry, my bad. It was pointed out to me that what I had indicated as a current measurement point was actually the symbol for a current source. It's been corrected.

author: magic
author_rank: Super Contributor
timestamp: November 01, 2024, 12:53:31 pm
content: The only one component solution coming to mind:Vsupply --- load --- (-)battery(+) --- current sink --- GND

author: Analog Kid
author_rank: Super Contributor
timestamp: November 04, 2024, 06:47:08 pm
content: I'm happy to report that we've gotten some good results prototyping this circuit (the "hybrid" or cascaded current mirror) here at AnalogKid Laboratories, GmbH. (Prototyping IRL, not Spice.)Here's the circuit as tested:And here are the test results. Currents in μA.(The first 2 values are from DMMs, the last from an analog meter, estimated reading)Not too shabby for a discrete circuit: ~2% error or so. (I did match the mirror pairs by beta, using my handy-dandy rig made from@PCB.Wiz's design.) The results are good enough to encourage me to proceed to the next step here; this is part of a larger project; details TBA. (Please bear in mind: this isnotintended to be a high-precision circuit. For that one would want to use opamps, probably.)You'll notice that there are some slight discrepancies here: the intermediate mirror current ("B") is higher than the set current ("A), and the output current is lower than the intermediate but almost equal to the input current. Now I'm not attributing that to any inherent behavior of the circuit: I think I was just visited by Lady Luck here.One question, though, about the emitter resistors:I played with different values here, starting at 0 (no resistors). The current tracking definitely improved with higher resistance. But the question is, where is the "sweet spot" here? I could increase the resistance further, but at some point that's going to affect circuit operation by limiting current, amiright? So here's where the art of electronics (to use a famous book title) comes in.I guess my question is: at what point does this resistance start to adversely affect mirror operation? And how does one calculate that point? (Yep, I guess there's no getting around some math here ...)

author: TimFox
author_rank: Super Contributor
timestamp: November 04, 2024, 07:18:49 pm
content: For the accuracy of the mirroring, it improves without limit as you increase the resistors, but the voltage drop across the higher resistors requires higher supply voltages: not a scheme that can be "optimized".Note that for matching the transistors, it is more important to matchVbe(at or near the operating value ofIc) than to matchhFEfor each pair, especially if yourhFEmatch is at a very different value ofIc.

author: Analog Kid
author_rank: Super Contributor
timestamp: November 04, 2024, 07:26:26 pm
content: Quote from: TimFox on November 04, 2024, 07:18:49 pmThanks. I guess my question would then be: this being the case, what guidelines would I use to determine the ideal supply voltage to this circuit? Let's say the circuit of which this is a part operates at 5 volts: any guideline to what VCCshould be here to operate "correctly" (however that's defined)?Or is this just another "seat of the pants" thing?

author: Analog Kid
author_rank: Super Contributor
timestamp: November 04, 2024, 07:28:20 pm
content: Quote from: TimFox on November 04, 2024, 07:18:49 pmMaybe it's time to build a Vbetest rig.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: November 04, 2024, 07:30:19 pm
content: Quote from: Analog Kid on November 04, 2024, 06:47:08 pmYou can get a simple ballpark, by looking at the drop.Your 220R drops 5.5mV at 25uA which is 0.1% of your available supply.5.5mV is not much compensation for typical VBE variations, more typical design method might be to target (say) 200mV drop, still just 4% of your supply, which swamps any (say) 2mV VBE variation.If you want a wide dynamic range, you will need better VBE matching.

author: tggzzz
author_rank: Super Contributor
timestamp: November 04, 2024, 07:32:54 pm
content: Quote from: Analog Kid on November 04, 2024, 07:26:26 pmNo, fortunately it isn't. The theory is well understood and documented in the literature.

author: Analog Kid
author_rank: Super Contributor
timestamp: November 04, 2024, 07:34:59 pm
content: Quote from: tggzzz on November 04, 2024, 07:32:54 pmCare to explain a little further?

author: tggzzz
author_rank: Super Contributor
timestamp: November 04, 2024, 08:07:26 pm
content: Quote from: Analog Kid on November 04, 2024, 07:34:59 pmI refer you to my earlier replies in this thread.If you haven't got TAoE and x-chapters, get them.

author: Analog Kid
author_rank: Super Contributor
timestamp: November 04, 2024, 08:43:38 pm
content: Quote from: tggzzz on November 04, 2024, 08:07:26 pmOh, you again.Y'know, I've really had it with you. Up to here.Instead of answering a simple goddamn question, you're back to badgering and browbeating me. You took the time and energy to reply but didn't expand on your earlier explanation. Instead we're back to "read the fucking book".First of all; I have TAoE. In fact, for what it's worth, it's a copy given me by a friend who's also a friend of Paul Horowitz. Not an Internet correspondent but an actual friend. Maybe I should ask him (I've never met the guy).But you: again, you're not my Electronics 203 professor. You don't get to dictate my homework assignments.But hey, maybe you're right: maybe we should just shut down this forum, and all others like it. Replace them with a page telling those who have questions about electronics to just read the books, and provide a reading list. Would that be more to your liking?You and your ilk are those who just make life more annoying. As an Electronics Guru®© you get to decide just how much some poor schmo needs to know before they're granted the benefit of your knowledge. If they don't show sufficient knowledge, then it's back to school for them, and don't bother me with any more questions until you've done all the odd-numbered exercises at the end of the chapter.With you in charge, nobody would really be able to learn anything; they'd be stuck in stasis, except for those few souls who follow your instructions to the letter, keep their nose to the grindstone. But I suppose you'd be happy with that outcome, as suits a gatekeeper type like yourself.Anyhow, my response to you is one you might be familiar with from Usenet days:*plonk*.

author: Someone
author_rank: Super Contributor
timestamp: November 04, 2024, 10:10:57 pm
content: Quote from: Analog Kid on November 04, 2024, 08:43:38 pmInstead of learning fundamentals you keep asking everyone else to answer overly specific trivial questions....Goes both ways.

author: Analog Kid
author_rank: Super Contributor
timestamp: November 04, 2024, 11:03:53 pm
content: Quote from: Someone on November 04, 2024, 10:10:57 pmPeople learn at different rates. Some of us are slower than others. So sue us.I guess one has 3 choices when considering whether and how to reply here:Answer the question as best you canGive the question-asker a rash of shit for daring to ask such a stupid questionor just STFUSince you mentioned "learning fundamentals", what about all those poor schmucks here who can barely connect up a battery and a light bulb, and whose knowledge of electronics is limited to their experience trying to assemble some god-awful "instructable" project? Would you just thrown them under the bus because of their limited knowledge? I hope not.BTW, and this is directed to@tggzzz: You have noticed, haven't you, that there are other people here who are happy to answer some of these questions?

author: tggzzz
author_rank: Super Contributor
timestamp: November 04, 2024, 11:29:19 pm
content: Quote from: Analog Kid on November 04, 2024, 11:03:53 pmMy posting history indicates I am more than willing to help people, with one proviso. They must show they are willing to listen and to put the effort into learning. Without that there is no way youcanbe helped.If you can't understand Ebers-Moll, won't use Spice, and haven't read the directly relevant parts of TAoE, then your learning curve will be long and slow.But you are right, therearesome other people in your position. To help them people have taken the time to write things likethisandthis

author: magic
author_rank: Super Contributor
timestamp: November 05, 2024, 06:21:01 am
content: Quote from: Analog Kid on November 04, 2024, 11:03:53 pmWell, fine, but do you know why you are slower than others? Because tggzzz's posts could be charitably interpreted as a suggestion that perhaps your approach isn't entirely efficient and that's why. If you simply accept this "slowness" as an inherent limitation, but if it actually isn't, you are only wasting your (and other people's) time.Or maybe tggzzz is just an asshole. Not gonna debate that. One possibility doesn't even exclude the other, and the real assholes will tell you the truth while being assholes about it, just to watch you disregard them and continue suffering. That's what I would do, you can sue me I guess

author: tggzzz
author_rank: Super Contributor
timestamp: November 05, 2024, 12:06:38 pm
content: Quote from: magic on November 05, 2024, 06:21:01 amInhisprevious thread about current mirrors,otherpeople noted the OP ignored direct answers to his questionshttps://www.eevblog.com/forum/beginners/current-mirror-explanation/msg5686189/#msg5686189. Several people spent their time providing detailed useful references several times during the thread, mostly with similar results.Some people can't be helped, and for whatever reason are unable to help themselves, and feel others are to blame for that. Shame.