3.3V voltage regulator

Hello. I would like to have 3.3V output with enough current from the arduino. I read that LM1117 is suitable for this case. I searched and find 3 different approaches

a)LM1117

b)DC 5V to 3.3V Step-Down Power Supply Module AMS1117-3.3

c)DC-DC Converter Adjustable Step down Power Supply Module

What are the differences and which of them is more efficient? I see that the (b) circuit has the (a) component. What are the other components and are they necessary?
Thanks!

see that the (b) circuit has the (a) component. What are the other components and are they necessary?

They are decoupling capacitors and the voltage reference divider. Necessary only if you want the regulator to work, if you are not bothered then don't fit them.

Circuit c is more efficient because unlike circuit b and component a ( not a circuit is it ) the excess power is not converted into heat. It is also the most expensive.

Grumpy_Mike:
They are decoupling capacitors and the voltage reference divider. Necessary only if you want the regulator to work, if you are not bothered then don’t fit them.

Circuit c is more efficient because unlike circuit b and component a ( not a circuit is it ) the excess power is not converted into heat. It is also the most expensive.

Hello Mike, since you are here and regarding the subject .
how does the capacitors that are usually used with regulators influence output current ?

Grumpy_Mike:
Necessary only if you want the regulator to work, if you are not bothered then don't fit them.

Sorry, but what do you mean if I want the regulator to work? I want to connect is with the esp8266. Can I connect it only with (a)?

Grumpy_Mike:
Circuit c is more efficient because unlike circuit b and component a ( not a circuit is it ) the excess power is not converted into heat. It is also the most expensive.

Thanks for the answer! What about the (c) and this:
LM2596 Power Supply.

Moreover, I would like to know which of all is more efficient about consuming energy. Thanks!

what do you mean if I want the regulator to work?

I mean if you want a stable voltage out of the regulator then you need the components.

What about the (c) and this:

They are both switching regulators.

I would like to know which of all is more efficient about consuming energy.

A switching regulator is more efficient at using electricity than a series regulator. With a switching regulator you get about 80 to 95% efficiency of conversion.

how does the capacitors that are usually used with regulators influence output current ?

They make the regulator, which is basically a feedback amplifier stable. Without them or even enough capacitance the regulator can oscillate instead of producing a steady voltage output.

Thank you very much Mr Grumpy_Mike!

thank you very much Mike

I see that the (b) circuit has the (a) component. What are the other components and are they necessary?

See section 8.2.2.1 of the [manufacturer's datasheet[/url].

The reason that capacitors are not built-into the integrated circuit package is that capacitors (and inductors) are made with different manufacturing processes and cannot be made on a silicon chip. (You can make small-value capacitors and inductors on silicon, but not the types/values needed for these circuits.)

](http://www.ti.com/lit/ds/symlink/lm1117.pdf)

First picture is a bare 3.3volt regulator (there are also other voltages available).
You need capacitors from input and output to ground to make it work.
They have nothing to do with output current.
Without them the regulator will oscillate, produce the wrong voltage, and could distroy your connected load.

The second picture shows the same regulator, but with the capacitors fitted.
It also has an onboard indicator LED, so you also can see if it works.

The third picture shows a switching regulator.
Much more efficient than the 1117 lineair regulator.
Less heat and more current available.

Don't expect to draw much current from the LM1117 on that small board.
Maybe just ok for what you are doing with 5volt going into the LM1117.
Not ok with e.g. 9volt or 12volt in.
Heat will quickly become a problem.

The switching regulator (picture 3) could easilly output 1 or 2 Amps, even with 12volt input.
The LM2596 is just a bigger/older/ less efficient version.
Bit more output current (not needed in this case) at the cost of less efficiency and higher idle current.
Leo..

What was not clearly described in the OP, is whether the intention is to obtain 3.3 V from 5 V, or from a higher voltage input.

If you are feeding it from 5 V, then it is most unlikely that a switching regulator will have any advantage in efficiency. And in this case also, the heat dissipation is so low that a module such as described in "b)" will be good for a few hundred milliamps - as the description suggests.

Thanks for the answers! I would like to obtain 3.3V from 5V.

Your option "b)" should do it then.

Thanks for the answers. Moreover I would like to ask what is the differences between the above circuits and logic level converter

Logic level converters do what the name suggest: They convert the logic level, that is, the voltage you are using for the logic. If the Arduino sends bits to the ESP8266 at 5V, the inputs of the latter will be damaged. So the voltage has to be reduced to 3.3V, which is what the converter does. It needs to be powered with the lower voltage.

BTW: If saving power is not an issue (i.e. you are not running on battery, and perhaps not even for a long time), you can also consider a linear regulator instead of a step-down switching supply.

maybe its time to tell exactly what you want to do ....
because, as ElCaron says, the devices are completely different . The first in the topic are voltage regulators, used as power supplies . The logic level converter is used for example between a 3.3V sensor input/output and a 5V arduino input/output .
You cannot use a regulator for that, and you cannot use a logic level converter as a power supply.

Have a look here

ElCaron:
BTW: If saving power is not an issue (i.e. you are not running on battery, and perhaps not even for a long time), you can also consider a linear regulator instead of a step-down switching supply.

See reply #9.