# LDO Regulator Circuit

1. ## LDO Regulator Circuit

Hello. I'm an ECE student. I would like to ask anyone here who can give LDO circuit with the parameters of 0.3V-5V input and 8mA outpu current. Thank You.

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2. ## Re: LDO Regulator Circuit

Your specification is incomplete and unclear.

What is the required output voltage? Is a variable output range as well?

Even an LDO linear regulator has a minimum dropout voltage, an input voltage of only 0.3 volts would like NOT be sufficient for voltage regulation except for a few millivolts output.

BigDog

3. ## Re: LDO Regulator Circuit

As far as your input voltage level is concern you will be able to generate 3.3 volt. Is that is your required voltage level?

4. ## Re: LDO Regulator Circuit

Thank You for the response. That's what our professor gave us. Can you give me LDO circuit?

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5. ## Re: LDO Regulator Circuit

Hi,

You want to use one of these IC´s and build the necessary circuit around the IC?
Or do you want to develop your own LDO circuit? (With reference, error amplifier, power stage and so on)

Klaus

6. ## Re: LDO Regulator Circuit

I would also suggest you reconfirm the input voltage range of 0.3 to 5.0 volts as the lower range limit of 0.3 volts is not particularly reasonable for most applications.

BigDog

7. ## Re: LDO Regulator Circuit

I second the motion of the input voltage range.....0.3 volt input is absolutely unreasonable. How much will your output be, 0.25 volt?
What are you powering with such a low voltage?

I'm going to chime in a personal anecdote:
When I was an EE student, I also had an electronics professor that would give us an assignment of, let's say, a 4 transistor amplifier, and ask us to fully analyze its DC-bias point. This was in pre-SPICE days, one had to calculate it manually.
Where an NPN transistor was supposed to be, he had actually drawn a PNP.
Most of the class assumed it was a typo, although the transistor part number was indeed for a PNP transistor, and proceeded to analyze the circuit -as is.

Only a friend and myself wrote a note on the analysis: "as drawn the circuit can't work, however, if its replaced by a NPN, the bias points are..."
Needless to say, the professor flunked everybody, EXCEPT my friend and myself. He then admonished us: "In your professional career, if you find a specification, a device, or a value that doesn't make sense...it doesn't matter from where or from whom is coming from, QUESTION IT!"

That has been one of the most valuable pieces of advice I have ever received.

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8. ## Re: LDO Regulator Circuit

Originally Posted by schmitt trigger
a 4 transistor amplifier, and ask us to fully analyze its DC-bias point. This was in pre-SPICE days, one had to calculate it manually.
And that is the way to do it. Always put theoretical analysis by hand first, and then with simulation correct yourself. These days, I find it wrong to let those kids in maths classes calculate with a calculator instead by head.. and professor that allows them...

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9. ## Re: LDO Regulator Circuit

Originally Posted by CataM
These days, I find it wrong to let those kids in maths classes calculate with a calculator instead by head.. and professor that allows them...
Due to the technology all these things were started happening. In One case it shows our whereas in other it is making us lazy . There are seriously so many shorter ways available through which we can start doing calculation at the speed of almost to calculator which I leaned from my professors... Missing those Good old days..

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