Are these mosfets good or shot

Discussion in 'The Projects Forum' started by brad20, Apr 15, 2014.

  1. brad20

    Thread Starter New Member

    Apr 7, 2013
    Hi Im using a dca55 transistor tester by peak and im seeing for threshold between 4.61v - 4.90v are these parts fried or still good note wrapped in paper with rubber band around the plastic parts in a used esd bag sealed. There 100 amp n ch unifet mosfets 500v. The data sheet says threshold should be between 3-5v max. In the same package I received 62 amp 250v mosfets they read 3.25-3.35v for threshold on same tester as mentioned above but were in those plastic used antistatic holders instead of wrapped in paper . thank you in advance
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    Since 3V < 4.61V < 4.90V < 5V your parts are completely within specfication.

    Wrapping anything with ESD sensitivity is (at best) a poor practice but does not guarntee the parts are damaged.
  3. brad20

    Thread Starter New Member

    Apr 7, 2013
    Is it better wrapping them in paper compared to putting them in a plastic bag for shipping purposes. My other parts from same source are 3.25v- 4.14v but the 4.90v if it were 5 it would be out of spec? for gate thresh hold. Would you return these parts being so close to to the 5v mark?
  4. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    The transistor tester tests that they are working. It turns them on/off and finds the gate threshold voltage.

    If the transistor was faulty it should be detected by the tester and display a fault message.

    I think you can res asssured the transistors are fine, assuming they are brand new.

    The probability that all the parts got zapped equally and now all of them measure the same error is practically zero.

    They are new and normal.
  5. KL7AJ

    Senior Member

    Nov 4, 2008
    It's best to use anti-static bags. They're readily available, and worth the trouble.