Talk:Voltage regulator

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sir, i want to design a voltage-regulator of 54VDC and max load current of upto 5Amp.The max input voltage is 60VDC and the range of voltage at the output of regulator must be within 48-54Vdc.suggest ckt.

thank you

What is the min input voltage? If you want a linear regulator circuit, perhaps something like http://sound.westhost.com/project96.htm would be adequate, with paralleled output transistors (you'll need a big heat sink on the output transistors). If you want a switching regulator, I see the LM5005 "integrated switcher" can handle the voltage, but only half your desired current -- perhaps use 2 of them. Or you could use a "switching controller" such as the Roman Black voltage regulator with an external high-power transistor. Digikey lists dozens of FETs that appear to be more than adequate for around $2, such as the 500 V 12A Toshiba 2SK3568(Q). --68.0.120.35 19:16, 5 January 2007 (UTC)

Contents 1 Merge 2 The LM2825 3 charge pump regulators 4 CVT Vs Voltage Stabilisers

[edit] Merge

As far as I can see from a quick search on the Internet, the terms VRM and Voltage regulator module seem to always refer to components specific to use in personal computers [1]. The electronic component or circuit in general is called voltage regulator (without module). Two separate articles can be justified in this case. Paolo Liberatore (Talk) 14:22, 5 November 2005 (UTC)

Since mine was the only opinion on the matter, and I am contrary to the merge, I am happy to close the discussion by stripping off the merge tags. Paolo Liberatore (Talk) 20:54, 19 November 2005 (UTC)

[edit] The LM2825

The LM2825 was just cited by an editor as an example of an integrated circuit that contains a high-value inductor. Unfortunately, the LM2825 data sheet doesn't support this claim. Here's what National says [2]:

Contained within the package are all the active and passive components for a high efficiency step-down (buck) switching regulator.

So it sounds like this rather-overweight 24-pin DIP contains discrete passive components as well as the IC chip. I've reverted this editor's change. Atlant 15:23, 14 July 2006 (UTC)

A switching voltage regulator needs an inductor to store energy, thus there must be some sort of inductive device in the PDIP package. Also, since the price per chip is around 20$, I wouldn't be surprised if National has a special manufacturing process for this chip. Perhaps we could add a small paragraph on integrated coils in ICs (with references) since the current paragraph is somewhat contradictory. --Jcmaco 22:50, 14 July 2006 (UTC)

I reverted this because I don't agree with "impossible". It is possible [3], although not really common. CyrilB 20:24, 14 July 2006 (UTC)

The key is "large-valued". A large-valued inductor is currently "impossible".

Atlant 13:16, 17 July 2006 (UTC)

I'll leave it, but I still dont agree. A large value inductor is not needed for a converter, provinding it has a high switching frequency. This sentence is inacurate, and the use of the word "impossible" makes it definitely inacurate CyrilB 15:14, 17 July 2006 (UTC)

Okay, I'm game: to achieve a fairly good current flow (and I'll leave the definition of that up to you), what value of inductor would you use with what practically-acheivable switching frequency? Then, how big would this inductor be when rendered onto an IC using normal metalization thicknesses? (Presumably, it would be the moral equivalent of an air-core inductor since current IC processing techniques don't allow for ferrite or other good core materials. Don't forget to account for electromigration and other nasty effects in designing the "winding".)

Would such an inductor be practical? If the answer is "yes", then edit the sentence removing "large value" and giving your specific example. But if the answer is "no", then the statement is correct as it stands: a large value inductor is "impossible" given the current state of the art.

Meanwhile, have you looked at recent reasonably-high powered brick designs? The inductors and transformers used there, even though relatively low in value (inductance) and composed of just a few "turns" created on the printed circuit board, still use a fairly large ferrite core strapped around the PC board. There just ain't no technology for making an adequate inductor directly on a small modern silicon IC chip.

Atlant 15:52, 17 July 2006 (UTC)

I'm not an expert in microelectronics, and I watch the work on integrated magnetics from a distant eye, but I know that several research groups work on this topic. The objective is to achieve switching frequencies of some MHz to several tens of MHz. This results in inductors in the 100nH range (roughly estimated, give or take a factor 10...). One of the issue is to generate ferrite powder that can be dispensed using a technique compatible with IC processing. I won't enter in further details, as I'm not an expert, and this field might be too speculative to be added to wikipedia. As I told before, my only concern is the use of the word "impossible", which is simply not true, as prototypes have already been realised. And by the way, I've just noticed that the article only addresses converters that use an inductor as storage device, not the others. Do integrated charge pump regulators exist? (this is a true question).

For the brick converters, the objective is to get the maximum power in the minimal space, so the inductor has to handle high current (several tens of amps are common), hence the big core. In an IC, the objective can be very different, for example having a very high-dynamic in the control of the converter.

To be clear, I don't want to start an edit war on some anecdotal (at least for me, not for the researchers of the domain!), and -I agree- non commercially available technology. I simply disagree with a definitive sentence which is not true and adds nothing to the article. But if you want to keep it as is, go ahead! CyrilB 20:33, 17 July 2006 (UTC)

I agree that the LM2825 appears to have a discrete inductor attached to the chip inside the plastic package. Rather than use the term "impossible", would everyone be happy with a compromise saying something like "All commercially available switching voltage regulators either include a discrete inductor or require the user to supply a discrete inductor." ? --76.209.30.239 22:33, 31 December 2006 (UTC)

That's okay for me, you can even say that the "external inductor" kind are by far the most common. CyrilB 18:33, 2 January 2007 (UTC)

[edit] charge pump regulators

The "voltage regulator" article needs to mention charge pump regulators.

Do integrated charge pump regulators exist?

If you are looking for voltage regulators that do not require an external inductor, then yes, many "single-chip" charge pump voltage regulators exist. They don't have any inductors, internal or external. They do require a few more external capacitors than other kinds of voltage regulators. --76.209.30.239 22:33, 31 December 2006 (UTC)

There are even a few charge pumps (such as the MAX233 and the MAX246) that don't require any external capacitors (only one cap across power and GND). Do they use on-chip capacitors (vaguely similar to DRAM), or do they use small discrete capacitors inside the package (more like a Multi-Chip Module and analogous to what the LM2825 apparently does) ? --68.0.120.35 19:16, 5 January 2007 (UTC)

[edit] CVT Vs Voltage Stabilisers

Can anybody guide whether CVT's can be used for elctric motors of capacity 1KW. Actually we have been using Voltage stabilisers on date but can we use CVT's for Electric Motors. Sanjivdogra 13:51, 10 February 2007 (UTC)