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Topic: 5V regulator AP7370-50WR-7 (Read 169 times) previous topic - next topic

Miniflyer

Hi guys,

Im not very smart concerning electronic components, but up to now my understanding of low drop regulators was that you need 0.5-1V higher input than output voltage.

Now i found the AP7370-50WR-7.....on the german mouser page it specifies input 3.2-18V with 5V out.

Is this even possible?

https://www.mouser.de/ProductDetail/Diodes-Incorporated/AP7370-50WR-7

Thanks for comments....

aarg

It's a misinterpretation of the specification. That parameter is the minimum to operate the internal circuits... 3.2V is specified because of the 1.2V - 3.6V output versions.
  ... with a transistor and a large sum of money to spend ...
Please don't PM me with technical questions. Post them in the forum.

Miniflyer

I was suspecting that.....too bad, that would have worked perfectly for me.

So lets rephrase that: if i am running a 5v nano, and want to be able to power from 4.5V-20V, how would you go about that? Step-down to 3.3V and then back up to 5V?

gilshultz

You are correct, Low Drop Out is referring to the output voltage + the drop out voltage = the minimum input voltage. Note you need to account for any ripple. The minimum voltage at the low voltage point is the minimum the regulator needs. You almost have the data sheet figured out. The part you chose is available in many output voltages (1.2V, 1.5V, 1.8V, 2.8V, 3.0V, 3.3V, 3.6V and 5.0V). What you need to do is add the drop out voltage to the output voltage, that is the minimum voltage you need under full load.  It will not boost the voltage. The data sheet is confusing on this aspect.
This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil

Miniflyer

That was my understanding. Thanks for clearing it up, im really not all to bright on the datasheet side

Back to the problem: are there step-up/down converters for 5v?

I have found converters on aliexpress putting out 3.3V with an input range of 1.8-5.5V......is there something similar for 5V or do i need to go down to 3.3 and back up to 5.0?

gilshultz

Yes but you have to leave the analog world for boost in voltage.  I typically use SEPIC converters. The single-ended primary-inductor converter (SEPIC) is a type of DC/DC converter that allows the electrical potential (voltage) at its output to be greater than, less than, or equal to that at its input. The output of the SEPIC is controlled by the duty cycle of the control switch. If your input voltage is higher then wanted you use a BUCK converter. Conversely if the input voltage is below what you want you use a BOOST converter. If the input can be higher and or lower then what you want during application you want a SEPIC converter. Most are available for a few dollars at most from your favorite china suppler. I typically use a SEPIC converter that hides a low of power problems and transients from my application.
This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil

Miniflyer

Now those do look interesting!

Without trying to decode hundreds of datasheets: do you have a reccomendation? I'd love 4-12v (not mad about wider spectrum), and 300-500mA will be plenty (arduino nano, gps and sd card power)

Thanks!

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