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LINEAR REGULATOR. 5-100Vin, 2-??out. Prefer 1A output.

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fastline

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We are trying to find a high voltage reg. They are not as abundant. I am having a hard time finding 1A of output and with a low drop out. I have found a Ti piece that is 5-125V in and 700mA out but requires a min of 20V delta from input to output voltage to reach max current rating. Our would likely run at 5V.

Are there any other mfgrs I might look at? Looked at Supertex and Ti so far.
 
Your power requirements (Vin = 5 to 125V, Vout = 5V at 1A) looks like you need a very unusual design. A simple "Linear regulator" would be dissipating 120W at maximum input (at 4% efficiency).

Your requirements are very unusual. We occasionally see all-purpose requirements like this posted by someone who doesn't understand the system they are designing.
 
It's not possible, the input current is only 700mA so you won't be able to get 5V@1A out with 5V@700mA in.

Even 5V to 125V to 5VDC@1A isn't easy to do efficiently.
 
I thought my question was fairly straight forward. Yes, I know what the circuit does, no, it will not be dissipating 120watts. No, we are not trying use 700mA/5V in and get 1A/5V out.

I am not quite sure every time I visit, my questions are more or less just a target for pros to take aim at and try to shoot holes through. We have reg with a Vdelta in of 450V and 20mA out. They would not make them and sell them if they would not work....
 
OK, what is your input voltage range? I tried using my crystal ball with the numbers that you did provide and I guessed wrong. If it is not 5-125V then were those numbers given as a diversion? And now, you mention 450V. Is that related to the device that you're seeking?

And what is your output current? I guessed 1A which obviously is wrong because now you say 20mA. Maybe it is some other number. Enlighten us.

When looking for a LDO regulator, the input voltage range and maximum current are paramount. You have given many numbers, none of which are useful. Do you not know how to define a regulator?

[edit - I see your title says you want 5-100Vin, 1A out, which means that it would be a whopping 5% efficient instead of the 4% that I said earlier, and would only dissipate 95 watts. I regret the error.]

The part that you need may very well exist but you won't find it by providing random numbers that are not related to your requirement.
 
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To get what you want, I think you are going to have to cook your own. To get the range you want, you will need a SCR phase control preregulator followed by a final regulator.
 
Supertex has a device (LR745) Vin 10-450, Vout 10 V at 4mA. They may have other parts too. Check their app. note AN-D17 for guidance. E
 
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