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Help identifying the SMD component

Krasimir

May 4, 2015
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Hi, please help identifying the burnt SMD component ( I suggest it is a MOSFET ). It is from 2.4 GHz AV transmitter (picture attached). There are partially remaining simbols on burnt chip (see freehand writing on right down corner ). I try to partialy track the PCB . I apply close view of the PCB also (both sides).
 

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mofy

Dec 19, 2014
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It is a switch mode regulator of some sort, stepping the input voltage down to a controlled level for the 78M05 so it doesn't dissipate too much power.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Actually it seems to provide another rail, so it's not just to reduce distortion in the 78L05, even though it does do that too.
 

Krasimir

May 4, 2015
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Thanks for your suggestions. First I also supposed the IC to be 9V voltage regulator but could it be a MOSFET , connected as reverse voltage protection, and that SMD component to be 2 MOSFETs in one chip.?
The IC is too tiny to be voltage regulator, which assure 0.5 A as 78M05 will. The input voltage is announced to be 9-12V DC.
If we assume the input voltage is 9V , would it works as regulator?

When I post this topic ,as a last chance , I hoped that somebody has the same transmitter and will be kind to check the chip.
I spent about a week in searching the net for close view of the transmitter PCB and suitable IC , but with no result. I even can't find a chip manufacturer with such a logo.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Why do you think it's too small? Switching regulators do not dissipate a lot of heat.

If your circuit diagram is correct ( and it looks like what I'd expect) then it is a switching regulator.
 

Krasimir

May 4, 2015
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Thank you very much. You are right.
I found a XLSEMI switching regulator XL 1509 , with the same pin configuration and the same application circuit usage.
It must be this chip or similar one. Thanks again.
 

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(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Well done! The one you need is the one with the adjustable output voltage.
 
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