I am trying to simulate short circuit protection of mosfet.Idea is when current becomes high,voltage across Rsense increases to 0.7v, Hence transistor conduct. Shorting source and gate.But it does not seem to work .Transistor conduct even when resistance is very low.

enter image description here

  • 2
    \$\begingroup\$ You could test a widely used DESAT circuit for MOSFET/IGBT protection, instead of reinventing the wheel. \$\endgroup\$ – Marko Buršič Oct 3 '15 at 18:05
  • \$\begingroup\$ Agree with Marko, use the proven desat circuit- e.g. here irf.com/technical-info/appnotes/an-1014.pdf \$\endgroup\$ – SunnyBoyNY Oct 3 '15 at 18:09

The base to collector is forward biased. The transistor is behaving like a diode.

  • 1
    \$\begingroup\$ After this I am gonna kill myself. Just kidding.Thank you very much. \$\endgroup\$ – jokeroor Oct 3 '15 at 18:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.