4 ms·

Straight from the horse's mouth (mosfet datasheet): Note: Using continuously under heavy loads (e.g. the application of high temperature/current/voltage and th

by 05 1y ago

Straight from the horse's mouth (mosfet datasheet): Note: Using continuously under heavy loads (e.g. the application of high temperature/current/voltage and the significant change in temperature, etc.) may cause this product to decrease in the reliability significantly even if the operating conditions (i.e. operating temperature/current/voltage, etc.) are within the absolute maximum ratings. Please design the appropriate reliability upon reviewing the Toshiba Semiconductor Reliability Handbook ("Handling Precautions"/"Derating Concept and Methods") and individual reliability data (i.e. reliability test report and estimated failure rate, etc). [0] https://www.mouser.com/datasheet/2/408/SSM6J402TU_datasheet_en_20240930-1627297.pdf https://www.mouser.com/datasheet/2/408/SSM6J402TU_datasheet_...

userbinator 1y ago
That's... not very confidence-inspiring. Something like the SiA471DJ comes in the same pinout and package, has almost 1/10th the on-resistance, and over 10x the current rating. Moreover, its datasheet does not have such a lengthy disclaimer about its abilities: https://www.vishay.com/doc/?76741= https://www.vishay.com/doc/?76741= If I were in the same situation I'd choose that part for a replacement --- sources online show it's basically the same price, and why replace it with the same failure-prone part just to risk it doing the same thing again? This isn't even a high-frequency application, it's just a power switch.
- RF_Savage 1y ago
  All mosfets are like that. The marketing folksbL at Toshiba just were not able get it removed, or they have had one too many complaint from folks running them near the absolute max while not cooling them properly.
mystified5016 1y ago
All datasheets for all parts contain a clause like this. Have you ever wondered how manufacturers get lifetime estimates? They use an accelerated aging process which basically just means they run the part very hot and back-compute how long it would take to fail at normal temperatures. This is an industry standard practice that is (supposedly, I haven't verified) well backed by science. Running a part at elevated temperatures is somehow physically equivalent to running them longer at lower temperatures. Heat and stress degrade silicon junctions. It's just physics. There's nothing particularly sketchy or unreliable about this specific part on its own. Probably whoever designed the amp circuit just made a mistake and under-spec'd this part.

by 05 1y ago

userbinator 1y ago

That's... not very confidence-inspiring. Something like the SiA471DJ comes in the same pinout and package, has almost 1/10th the on-resistance, and over 10x the current rating. Moreover, its datasheet does not have such a lengthy disclaimer about its abilities: https://www.vishay.com/doc/?76741= https://www.vishay.com/doc/?76741= If I were in the same situation I'd choose that part for a replacement --- sources online show it's basically the same price, and why replace it with the same failure-prone part just to risk it doing the same thing again? This isn't even a high-frequency application, it's just a power switch.

RF_Savage 1y ago
All mosfets are like that. The marketing folksbL at Toshiba just were not able get it removed, or they have had one too many complaint from folks running them near the absolute max while not cooling them properly.

mystified5016 1y ago

All datasheets for all parts contain a clause like this. Have you ever wondered how manufacturers get lifetime estimates? They use an accelerated aging process which basically just means they run the part very hot and back-compute how long it would take to fail at normal temperatures. This is an industry standard practice that is (supposedly, I haven't verified) well backed by science. Running a part at elevated temperatures is somehow physically equivalent to running them longer at lower temperatures. Heat and stress degrade silicon junctions. It's just physics. There's nothing particularly sketchy or unreliable about this specific part on its own. Probably whoever designed the amp circuit just made a mistake and under-spec'd this part.