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Electronics => Electronics => Topic started by: airman00 on October 04, 2008, 07:10:14 PM

Title: 3.3V to 12V Converter
Post by: airman00 on October 04, 2008, 07:10:14 PM
Hello Everyone

I need to convert the 3.3V supply of the FT232R UART chip to a 12V supply .

I think I *may* have found the solution but would appreciate if someone can verify this for me.
Use the 2920A Regulator - http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=576-1750-5-ND
Heres the datasheet - http://www.micrel.com/_PDF/mic2920.pdf

According to the datasheet(well my interpretation of it) it can take anything between 2 and 26V and output 12V . So if I give it the 3.3V it will be fine and output my 12V
Title: Re: 3.3V to 12V Converter
Post by: szhang on October 04, 2008, 08:38:20 PM
wait, unless i'm completely wrong, linear regulators don't do step up voltage regulation.  I think you need something like a MAX232.
Title: Re: 3.3V to 12V Converter
Post by: Steel_monkey on October 05, 2008, 07:57:44 AM
Linear regulator will not convert 3.3V to 12.
Here is what you need (simple step-up) http://www.nomad.ee/micros/mc34063a/ (http://www.nomad.ee/micros/mc34063a/)
There are comercially available assembled step-ups ( with everything already in one package ), and they cost approximately 3-5 $.
Title: Re: 3.3V to 12V Converter
Post by: Trumpkin on October 05, 2008, 04:34:45 PM
Linear regulators STEP DOWN voltage by turning the excess voltage into heat.
Title: Re: 3.3V to 12V Converter
Post by: airman00 on October 06, 2008, 12:07:33 PM
What about this one: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=LT1109CS8-12%23PBF-ND

Datasheet :http://www.linear.com/pc/downloadDocument.do?navId=H0,C3,P1363,D2533
Title: Re: 3.3V to 12V Converter
Post by: Trumpkin on October 06, 2008, 06:04:55 PM
That should work.
Title: Re: 3.3V to 12V Converter
Post by: Admin on October 10, 2008, 04:25:55 AM
Quote
3.3V supply of the FT232R UART chip to a 12V supply
If you look at the datasheet, you'll see that the output current on the 3.3V line is pathetic. If you boost the voltage, and not even factoring in inefficiencies, the current will drop even further.

Basically, check current limitations . . .