Author Topic: Coupled ferrite to isolate DC-DC power supply  (Read 147 times)

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Offline Yaroooo

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  • Country: it
Coupled ferrite to isolate DC-DC power supply
« on: April 10, 2020, 10:40:20 am »
Hi all,

as title, I'd like to add an isolated power supply to my circuit. I've a unknown power source that is declared 24V DC that I must use to power my circuit in an isolated way. I'll have an absorption between 0.5A to 1A on my circuit with an operative voltage of 12V.

There're different already made isolated DC-DC , with high prices, that convert from 24v to 12v. But maximum ratings are below my requirements, since input voltage may be higher and output current is very low.

Searching I've found this two type of products:
LPD4012-331NRB
MSD1278-472MLD

There's different type of converters application listed on this product datasheets. What is the lowest cost switching controller that I can pair with this circuits to perform DC-DC step-down? (something like a historical low cost IC)

I've also another question, can I just use this coupled ferrite like a transformer to power supply a LDO or a switching? I mean put it between my power supply and my voltage regulator, since it's 1:1 ratio and DC:DC I should not have additional components instead some caps. In this way I'll have ad isolation between source and board.

Thanks for any answer to my newbie question!
 

Offline gbaddeley

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  • Country: au
Re: Coupled ferrite to isolate DC-DC power supply
« Reply #1 on: April 11, 2020, 06:52:15 am »
A ferrite isolating transformer will not work DC - DC.  It requires a fairly high frequency AC driver, and then convert the transformer secondary back to DC. That’s why isolated DC - DC converter modules are not very cheap,  but you are probably better off by using one.
Glenn
 


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