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UCC21520: Bootstrapping and Gate turn on off Resistors
Part Number: UCC21520
for a typical halfbridge application. Maximum Gate charge for my MOSFETs is 45nC. Its blocking voltage is 600V. Max. . After calculation and considering in voltage ripple Bootstrap cap value come up with 800nF. i have decided to choose 1uF cap for this application. I have performed double pulse test just to observe switching behavior of MOSFETs.
1- I have chosen 18 ohm turn on resistance and 9 ohm for turn off.
During measurements there is voltage ringing during turn off and current ringing during turn on which is almost 1.5 times of drain to source voltage. i have still available gate to source resistor and capacitor options available. what values of these capacitor and resistor should be to reduce ringing. (R2 R3, C3 C4)
kindly have look in figers.
here is double pulse result for Vds = 200V.
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In reply to Mateo Begue:
In reply to Muhammad Ahmed72:
In reply to Derek Payne:
I have used IPP65R095C7 which has blocking voltage of 600V. DC link voltage is 400Vdc maximum. Let me be clear i was doing double pulse test by increasing Voltage step by step. I have inductor value 440mH. at 200 V my mosfet got dameged. Turn on R=18 and turn off =9 ohm, R2 and R3 is 1K and C3 C4 is 1n.
kindly find attached results when MOSFETs got damaged !
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