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Electronics => Repair => Topic started by: cybermaus on January 28, 2022, 08:11:19 am

Title: 5-pin SOT Voltage regulator TRDEC
Post by: cybermaus on January 28, 2022, 08:11:19 am
I know there are some website where you can look up those 3 and 5 letter codes, seen them before, but I cannot find them anywhere (should have book marked them)

Anyone knows which voltage regulator this is, or where to find those reference list websites?
Many thanks.

Additional info:
- Probably regulates from 5V to 3.3V
- It burns when you feed it 12V
- 1.5mm x 2.5mm in size (those stripes are half mm)
Title: Re: 5-pin SOT Voltage regulator TRDEC
Post by: Audiorepair on January 28, 2022, 12:37:07 pm
fzabkar provided me this link a couple of days ago, seems a good resource.

http://www.smdmark.com/en-US/search/code?id=DEC (http://www.smdmark.com/en-US/search/code?id=DEC)
Title: Re: 5-pin SOT Voltage regulator TRDEC
Post by: cybermaus on January 28, 2022, 12:47:55 pm
Thanks yes, sort of like that.

Though the one I remember, you could filter on both package (pins) and the 3-letter code.
And was not specific to a supply house. If only I had bookmarked it.

Anyway, thanks. Alas, I could find it on that list.
Title: Re: 5-pin SOT Voltage regulator TRDEC
Post by: fzabkar on January 29, 2022, 06:20:08 am
These appear to be pin compatible step-down converters. You need to match the feedback voltage, switching frequency, and max Vin. The size of the inductor would be a guide to the switching frequency and output current. Compare it against the inductors in the application circuits in the datasheets.

http://file2.dzsc.com/product/17/10/16/1129211_103315937.pdf (http://file2.dzsc.com/product/17/10/16/1129211_103315937.pdf)
https://www.maxlinear.com/Files/Documents/SP6669_DS_RevC.pdf (https://www.maxlinear.com/Files/Documents/SP6669_DS_RevC.pdf)
https://datasheet.lcsc.com/szlcsc/1903011605_JoulWatt-Tech-JW5222_C371424.pdf (https://datasheet.lcsc.com/szlcsc/1903011605_JoulWatt-Tech-JW5222_C371424.pdf)
http://www.broadchip.com/Public/Uploads/uploadfile/files/20210402/BCT1814.pdf (http://www.broadchip.com/Public/Uploads/uploadfile/files/20210402/BCT1814.pdf)
http://www.broadchip.com/Public/Uploads/uploadfile/files/20210402/BCT1812.pdf (http://www.broadchip.com/Public/Uploads/uploadfile/files/20210402/BCT1812.pdf)

There are plenty of other possible candidates:

https://ipv4.google.com/search?q=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+%22sot23-5%22+converter+%22step+down%22+OR+stepdown (https://ipv4.google.com/search?q=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+%22sot23-5%22+converter+%22step+down%22+OR+stepdown)

I would look for a compatible part from makers such as Monolithic Power, TI, On Semiconductor, STMicroelectronics, Vishay, Richtek. The pinout seems to be very common.

If you can determine the values of feedback resistors R39 and R40, then you should be able to calculate the feedback voltage, assuming that Vout is +3.3V.