View Single Post
  #22 (permalink)  
Old November 9, 2013, 03:18 AM
trodas's Avatar
trodas trodas is offline
Join Date: Feb 2008
Location: Czech republic
Posts: 353

My System Specs


Oh, man, that one suxx bad:
Semiconductor MTD15N06V
60V, 80mOhms, 15A, rise time 51uS, shutoff time 18nS
gate charge 14.4nC, gate treshold 2.7V!

60V is too high (unnecessary, source is 3.3V, output 1.5V), 15A is not much, but 80mOhms is notably worser that the 50mOhms it is there AND more resistance when current flow = more heat! And we did not like heat, did we? Also the rise time is 8.5x slower that with the original mosfet (6nS only!), while the shutdown is rougly same.
But with same gate charge is there a huge problem (hence the 60V unnecessarity) with the gate treshold. That is very very high 2.7V, while the original works at 1.2V. Therefore this mosfet probably will never even work in the mainboard... :(

...but from this very interesting link you posted:
Vishay - MOSFETs - N-channel - DPAK (TO-252) package
...I choose this one:

Vishay SUD50N02-06P
20V, 6mOhms, 26A, rise time 10nS, shutoff time 24nS
gate treshold 0.8V, gate charge 19nC

Even that at 4.5V the resistance is actually 9.5mOhms, then it is still far better that 50mOhms.
Also the mosfet can operate at 175C, witch is pretty high.
While it is a bit slower (rise time 10 to 6, shut off time 24 do 20), the gate treshold 0.8V should compensate that a bit for the original is 1.2V... The slightly higher gate charge 19nC over 15nC should not be a problem.

I believe I found the perfect replacement, that is better than the original!
"It is dangerous to be right in matters on which the established authorities are wrong." - Voltaire
"I believe that all the people who stand to profit by a war and who help provoke it should be shot on the first day it starts..." - Hemingway :) my config - my caps

Last edited by trodas; November 9, 2013 at 08:29 AM.
Reply With Quote