D
D from BC
- Jan 1, 1970
- 0
Can a 100khz converter get less hot with paralleled mosfets?
I have my single mosfet max'd out due to internal Rg using a Tr=14nS
gate driver... The heat sink gets too hot in my app.. Can I improve
the efficiency by paralleling mosfets..?
(Not using more parts to share the total power loss but reducing the
total power loss..)
Paralleling mosfets can reduce the conduction losses to reduce heat..
But no so with the switching loss. It is just divided among the
paralleled mosfets..In other words...No efficiency gain.. correct?
(I suspect I'm wrong on this...but not sure..)
Also...
I've read that paralleled mosfets can oscillate..
A fix is to use gate resistors and or ferrite beads to prevent
oscillations.
Wouldn't this slow down the mosfets and create more switching heat?
Compensate with higher Vg?
How large are these gate resistors..I can only guess 10 to 30 ohms??
Do smps designers resort to paralleling while maintaining the same
switching frequency for a cooler box?
Maybe paralleled so much that no heat sink is required?
D from BC
I have my single mosfet max'd out due to internal Rg using a Tr=14nS
gate driver... The heat sink gets too hot in my app.. Can I improve
the efficiency by paralleling mosfets..?
(Not using more parts to share the total power loss but reducing the
total power loss..)
Paralleling mosfets can reduce the conduction losses to reduce heat..
But no so with the switching loss. It is just divided among the
paralleled mosfets..In other words...No efficiency gain.. correct?
(I suspect I'm wrong on this...but not sure..)
Also...
I've read that paralleled mosfets can oscillate..
A fix is to use gate resistors and or ferrite beads to prevent
oscillations.
Wouldn't this slow down the mosfets and create more switching heat?
Compensate with higher Vg?
How large are these gate resistors..I can only guess 10 to 30 ohms??
Do smps designers resort to paralleling while maintaining the same
switching frequency for a cooler box?
Maybe paralleled so much that no heat sink is required?
D from BC