How safe/not safe is it to connect Vout voltage to output of AP2112K?
https://learn.adafruit.com/assets/93017
Adafruit Learning System (larger image)
I am not planning to use Vin, so the regulator will not have any power, apart from 3.3V applied to output. I am not familiar with how the output is designed and if the regulator can be damaged or would drain some power.
In the worst case I can just cut the 5th pin connection but if I can avoid altering the board I would prefer that.
Always check the data sheet. https://cdn-shop.adafruit.com/product-files/2471/AP2112.pdf
The functional block diagram suggests that you might be able to get away with applying a voltage to Vout, when the regulator is unpowered. But if it will never be powered, just remove it, or cut the PCB trace.
If you are planning low power operation, you should cut it. There may be some leakage current even if no damage or harm from the reverse voltage bias.
Thanks, yes, I dont think I will ever use it as my project is 3.3V, desoldering it could be challenging, PCB is too fine to cut, but I can easily just clip pin 5, or maybe desolder just this pin and leave it in the air just in case.
For a small part like that, I just touch the hot tip of a solder pencil to it for 2-3 seconds, and swipe it off.
It is really easy, but to gain confidence, practice on a discarded circuit board.
Not much space really (looks too big on picture)
That is a low dropout regulator, so power the module by applying 3.3V to Vin.
Again, from the data sheet:
What about it? Those are the specs for a 2.5V version of the regulator.
This is what you should be looking at:
What that, and the figure posted in reply #7 means, is that if you apply 3.3V to Vin, somewhere between 3.3V and 3.15V (at 600 mA) will appear at Vout, depending on the current draw.
Low dropout regulators like this are used on these modules, so that you can power them either with 5V or 3.3V (applied to Vin). The rest of the parts will function fine at 3.0V or a bit lower.
ah yeh, you’re right, 3.3v version is suggested to use 4.3 on the next table. Im going to test and come back
Fantastic! Many thanks, this is exactly what I was looking for @jremington
