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Electronics => Repair => Topic started by: fripp on November 26, 2024, 11:24:33 am

Title: Help needed identifying SOT23 with 43R symbol
Post by: fripp on November 26, 2024, 11:24:33 am

Can anybody shed any light on what this component maybe (Symbol=43R, Package=SOT23).  Center pin is grounded.  I have tried all the repositories I know of but no matches for 43R only 43 which throws up many options.

Title: Re: Help needed identifying SOT23 with 43R symbol
Post by: timeandfrequency on November 26, 2024, 12:36:14 pm

Hello fripp,

Something like a ZR431 (https://www.diodes.com/assets/Datasheets/ZR431.pdf) (TL431) ?
If you can power the board, measure the voltage at pin 2 (Vz) : it should match to ± 2 % with the calculated value (SMD resistors circled in blue; I cannot read the values because of the limited resolution of the provided pictures). The formula can be found in the datasheet (see 'shunt regulator').

Title: Re: Help needed identifying SOT23 with 43R symbol
Post by: fzabkar on November 26, 2024, 12:59:30 pm

http://markingcodes.com/search/c/43r (http://markingcodes.com/search/c/43r)

https://www.google.com/search?q=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+43r+sot23 (https://www.google.com/search?q=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+43r+sot23)

Title: Re: Help needed identifying SOT23 with 43R symbol
Post by: fripp on November 26, 2024, 02:04:51 pm

Thanks I think I am on the right track now