SIC MOSFET Qrr Question

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
KUOWENYUNG
Level 3
Level 3
25 replies posted 100 sign-ins 50 sign-ins

Hi IFXer,

SI/SIC MOSFETs all generate parasitic diodes through internal P+ - N- - N+ (PiN),
But why the reason for the lower Qrr of SIC MOSFET ?

Is it because the N-epitaxial layer of the SIC MOSFET is thinner (low resistivity), when the body diode is off, it can have a faster recombination effect, resulting in lower stored charge (Qrr)?

kind regards,

Kuo

0 Likes
1 Solution
sushank
Moderator
Moderator
Moderator
25 solutions authored 100 sign-ins 50 replies posted

Hi

yes you are right it is due to the thinner depletion region as compared to normal Si mosfet which has wide depletion region  causes extensive reverse recovery charge (QRR), which limits their usage in hard-switching configuration. also in Sic parasitic capacitance is also less as compared to Si, due to which there is less charge to discharge during turn off. 

View solution in original post

0 Likes
2 Replies
sushank
Moderator
Moderator
Moderator
25 solutions authored 100 sign-ins 50 replies posted

Hi there, 

do you have any specific part number in mind, ?   

0 Likes
sushank
Moderator
Moderator
Moderator
25 solutions authored 100 sign-ins 50 replies posted

Hi

yes you are right it is due to the thinner depletion region as compared to normal Si mosfet which has wide depletion region  causes extensive reverse recovery charge (QRR), which limits their usage in hard-switching configuration. also in Sic parasitic capacitance is also less as compared to Si, due to which there is less charge to discharge during turn off. 

0 Likes