Maker Pro
Maker Pro

MOSFETs shooting through in H-bridge: damage at gate-source driving circuits

BlackMelon

Aug 7, 2012
188
Joined
Aug 7, 2012
Messages
188
Hello,

In H-bridge, if gate-source driving signals of two MOSFETs on the left side of H-bridge are almost good, except only their phases, which are the same. Of course, the MOSFETs' drain-source junctions surely explode. But how about their gate-source driving circuits? If they are not opto-coupled, will there be a chance to breaking down?

Thank you
BlackMelon
 
Last edited:

Harald Kapp

Moderator
Moderator
Nov 17, 2011
13,700
Joined
Nov 17, 2011
Messages
13,700
But how about their gate-source driving circuits? If they are not opto-coupled, will there be a chance to breaking down?
I don't think a general answer can be given here. It depends on the mechanism of breakdown of the transistors. If the gate-source is short-circuited in the course of the destruction of the transistor, chnaces are the driving circuit "sees" voltages it wasn't designed for and is accordingly damaged.
 

GPG

Sep 18, 2015
452
Joined
Sep 18, 2015
Messages
452
Show circuit, there are drivers that take this in to account
 

BlackMelon

Aug 7, 2012
188
Joined
Aug 7, 2012
Messages
188
The file drive_drive.png is a MOSFET driver. There are two of them, which are completely isolated from each other. (There are two external square wave generators for each driver. The H-bridge comprising two MOSFETs and two diodes is in FlybackBridge.jpg
 

Attachments

  • Drive_Drive.PNG
    Drive_Drive.PNG
    15.6 KB · Views: 119
  • FlybackBridge.jpg
    FlybackBridge.jpg
    10.5 KB · Views: 110

Arouse1973

Adam
Dec 18, 2013
5,178
Joined
Dec 18, 2013
Messages
5,178
The circuit you show as FlybackBridge is a forward convertor... not flyback. I don't fully understand your question. Do you have a full circuit you can show?
Thanks
Adam
 
Top