Announcements

Register now for the most anticipated Asia Pacific Power Seminar 2022

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

MOSFET (Si/SiC) Forum Discussions

KUOWENYUNG
Level 3
50 sign-ins 10 replies posted 5 replies posted
Level 3

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 50 replies posted 10 solutions authored 50 sign-ins
Moderator

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 50 replies posted 10 solutions authored 50 sign-ins
Moderator

Hi there, 

do you have any specific part number in mind, ?   

0 Likes
sushank
Moderator
Moderator 50 replies posted 10 solutions authored 50 sign-ins
Moderator

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