When your MOSFET waveform looks like this… it's bad news.─影片 Dailymotion

Diagnosing "severe concussion" in MOSFETs. Follow for more advanced tech tips!

Transcript

00:00as a mosfet veteran you can spot a well-driven mosfet at a glance look at this rising edge worn

00:12smooth by life's grind now check that square wave still sporting its fresh out of college hair

00:19typically mosfets open slowly and close quickly a normal waveform shows a relatively gentle rise

00:28compared to the fall but this square wave defies convention its rapid switching speed causes the

00:35mosfet to oscillate slightly at this point savvy hardware pioneers increase the gate drive

00:41resistance take these to triangular like waveforms both the rise and fall edges are very gradual

00:48this pattern typically indicates insufficient drive capability from the driver chip at this point

00:55would replace it with a chip offering stronger drive capability now look at this it's high

01:00frequency ringing signaling severe oscillation in the mosfet most operate in the linear region

01:07incurring massive power dissipation that leads to mosfet burnout so what kind of problems do you often

01:15encounter