Il 01/12/17 16:30, mail@crcomp.net ha scritto:
> Massimo Gaggero <massimo.gaggero@gmail.com> wrote:
>> Hi all,
>>         looking for a cheap and easy to use DC Step-Down Step-Up Convert=
er to
>> 3.3V, I found this:
>>
>> https://www.banggood.com/3Pcs-Mini-2-in-1-DC-Step-Down-Step-Up-Converter=
-1_8V-5V-to-3_3V-Power-For-Arduino-p-1205021.html
>> that fits very well to my project.
>>
>> But searching for more details about the IC, the only clue is the
>> silkscreen 'N1IF', from which I cannot trace back to a datasheet.
>> Googling around I found this ad
>>
>> https://www.yoycart.com/Product/542865822576/
>>
>> claiming the 'N1IF' IC to be a "hx4002b" charge pump. But again, no
>> datasheet for "hx4002b" charge pump.
>>
>> Does anybody of you have seen or used this before?
>=20
>      The "b" may be only a tolerance suffix appended to a "hx4002" part.
> Did you see the hx4002 datasheet shown below? The recommended layout
> shown on page 9 of that datasheet seems at least superficially identical
> to the banggood image.
>=20
> url=3Dhttp://www.hxsemi.com/upfiles/20141031121620.pdf
>=20
> Thank you,
>=20

Yes, I have already checked the datasheet above, but what it says in the=20
Features outline is "Fixed 5V=B14% Output". From this, the two:
1) to obtain a 3.3 fixed output voltage a specific circuit is required=20
(but I couldn't find anything about in the datasheet);
2) the IC for the 3.3 V output has another part number, though from the=20
same family.

Thanks,
	Massimo.
--=20
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