Grumpy_Mike:
Please, can you explain why i need capacitors to input
To lower the impedance of the voltage source to prevent oscillation of the regulator.
1.0mF will be ok?
For those parts you linked to then yes. But only if the part is actually made by the same manufacturer who wrote the data sheet.
So i have find these:
7805
7905
7805 : 0.33 mF and 0.1 mF
7905 : 2.2 mF and 1.0 mF
I found all capacitor in tantalum but not the 1.0 mF
With what would be better to replace it? I was advised that ceramic is good too. And electrolytic is too slow.
But in these datasheet:
http://www.hep.upenn.edu/SNO/daq/parts/lm7915.pdf (it's not the same producer)
Say this: "²Required for stability. For value given, capacitor must be
solid tantalum. 25 mF aluminum electrolytic may be substituted.
Values given may be increased without limit."
So it's better 1.0 mF ceramic or 25 mF electolytic?
oric_dan(333):
How i can lower voltage to 3v3?
First off, many but not all standard-size Arduino boards have a 3.3V v.reg on board.
You can add your own on other boards, but the zener idea may work.Secondly, if you have an Arduino board that runs at 3.3V rather than 5V, you can
probably power it off a 5V regulator ok. However, you'll be running a bit close on loading
with powering from a 78L05, which can deliver only 100-mA. Would be better to use
a 7805 v.reg, ie 1 Amp device.Thirdly, if you have mixed systems of 5V and 3.3V, you will need level-shifters to interface
the 23K256 to 5V I/O pins on an Arduino.[Edit: I meant to say you can probably supply 5V to the Vin pin of a 3.3V board to power
the 3.3V v.reg on the board].
I've changed to 1 Amp devices, and i'll use raw pin on arduino pro mini (3v3 ver.). It'll be ok?