Low power voltage regulator

[yagtoby]

i havea device which works on 3 V battery source and consumes very very less power. But the circuit needs a constant power supply of 3 V.

i am looking for an ' low power voltage regulatior' circuit '.
Can somebody provide me a circuit.

Thanks in advance.

 

[Dr.EM]

I think your looking for a low dropout regulator, but if it needs exactly 3v and you have a 3v battery, you'll actually need a small switch mode boost convertor (there are some chips for this). The convertor will supply the constant 3v as the battery drops down to 2v etc.

 

[DirtyLude]

The only boost converter I have experience with is the MAX1674. Boosts anything as low as 0.7v up to 3.3v. I can run a whole project off a single AA battery.

Of course that doesn't help you if 3.3v is too much voltage for you. I'm assuming there must be similar parts for 3.0v if you look around.

Otherwise, to echo the above post, a regulator is not what you want.

 

[Dr.EM]

The MAX1674 may well be suitable for you, just use a schottky diode after it selected for 0.3v drop at the current your circuit needs.

 

[DirtyLude]

Actually, I just realized, the direct settings for the MAX1764 are 3.3v and 5v, but the output is adjustable from 2.0v to 5.5v. You'd have to check the datasheet to see how to do it. I think you need to create a reference voltage with a voltage divider.

The only problem is that the MAX1764 only comes in a tiny SOP SMD package. So that might rule it out as an option for many people.

 

[yagtoby]

Low dropout regulator

i have studied my ckt requirement, battery 3 V output with (- 2.8 to + 3.2) is Ok for my circuit. To try with MAX1674, i need a circuit. Could you post it.

Dirty lude - Your two posts mentions, one as MAX1674 and the other as or 1764 which is correct.

regards

 

[DirtyLude]

Re: Low dropout regulator

It would have taken less time to google search max1674 and max1764 and found your answer than it did to type your message.

It is in fact the MAX1674. The datasheet is available on the Maxim website www.maxim-ic.com and gives you all the information you need to know about how to get what you want from the chip. I will let you know that a 22uh inductor or higher is required.

It looks like Digikey only has the MAX1676 in stock, which is similar, but with added features. They are both listed as over $5.00, but I could swear I got mine cheaper than that.

I stress though, that this IC is very tiny, and unless you have a PCB, maybe impossible to work with. Here is a project that I used this IC. The max1674 is the top left IC. The last picture is the clearest. This is a 3.3v circuit and the max1674 runs the whole thing off of a single AA battery right now, though I will change it to 2 AA batteries, since I have room in the project box.

**broken link removed**

There maybe similar alternative IC's out there that are cheaper. Usually ST makes some nice alternative parts.

 

[Hero999]

What current?
Build a normal regulator with a low voltage power op-amp and use a PNP transistor on the output?

You could also use a low voltage 555 timer to boost it to 6V then use it with a normal op-amp and a PNP output transistor.

You could even get away without using an opamp and just use transistors but it wouldn't be very accurate - I'll show you a circuit if you like.

 

[tony.louis]

i havea device which works on 3 V battery source and consumes very very less power. But the circuit needs a constant power supply of 3 V.

i am looking for an ' low power voltage regulatior' circuit '.
Can somebody provide me a circuit.

Thanks in advance.

use ic LM 385. u can get 2.5 volts constantly.