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I am doing a datasheet comparison of the AUIRFP4568 and the IXTH150N15X4 MOSFETs. The MOSFET is for a three phase inverter working as MCU (Motor Control Unit) to control a PMSM motor, and will be driven with this gate driver from Infineon.

I am unable to conclude if the value given on both datasheets for dv/dt capability is comparable or not, as I am unable to understand the test conditions. Could anyone please guide me or share their opinion if the dv/dt capability of both MOSFETs is the same or different? If the same, then why, and vice versa.

What I mean by dv/dt capability here is with regards to turn-on and turn-off time. This has a direct impact on EMI related issues and this can lead to changing EMC requirements.

SamGibson
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Alison
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    What do you mean by "dV/dt capability" here? Body diode recovery time? Turn-on/turn-off time? What specific application are you evaluating the MOSFETs for? What's driving the MOSFET gates? – Polynomial Jan 19 '23 at 16:15
  • Or are you worried about dv/dt induced turn-on? – John D Jan 19 '23 at 16:35
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    18.5kV/µs is a mere 8ns to go from zero to Vds(max), you will have a hard time exceeding this (but it's probably possible). 50kV/µs, probably impossible by the transistors alone (one would have to be driven by a much faster type). Do you have reason to be concerned about this figure? Or is that the question, you don't know the significance of this figure? – Tim Williams Jan 19 '23 at 17:25
  • addressing to question asked by polynomial, what i mean by dv/dt capability here is with regards to turn on and turn off time. since this has direct impact on EMI related issue and this can lead to changing in EMC requirements. This mosfet is for three phase inverter working as MCU(Motor Control Unit) to control PMSM motor. Gate drivers from infenion. here is the link https://www.infineon.com/cms/de/product/power/gate-driver-ics/auirs21814s/ – Alison Jan 20 '23 at 08:13
  • john D , yes that is also something which i am worried about with regards to false turn on – Alison Jan 20 '23 at 08:13
  • Tim Willam, Thanks for your comment. Actually we are only concerned about EMI relate issues due to this high dv/dt. The device having 50V/ns dv/dt is fast switching device and we saw it double pulse test measurement as well that it has VDS spike of roughly 60V when we are switching 24V and 60A. Can you please elaborate your comment with regard to that – Alison Jan 20 '23 at 13:58
  • @Alison - Hi, Your question is easier for people to help with the links to the datasheets included in the question. Therefore I have reversed (rolled-back) your edit where you removed those datasheet links. – SamGibson Jan 23 '23 at 15:09
  • @Alison FYI I didn't see your comment as I was not tagged, put an '@' in front and you will see a list of names as you type. The dV/dt rating is just that, a rating, a maximum to avoid destruction; it says nothing about actual risetime in your circuit, which is defined by gate drive strength, device capacitance, stray inductance, load current, etc. – Tim Williams Jan 23 '23 at 20:21
  • @TimWilliams Thanks for your feedback. So what we can see here that one device has dv/dt rating of 50V/ns and other device has 18.5V/ns. So can we say that due to higher dv/dt, the device will be more vulnerable to self turn on as they stray capactinaces of low side mosfet can be charged due to voltage devloped due to higher dv/dt of high side mosfet at switching node? is there is any advantage as well of having higher dv/dt. what i know till now is that it cause some ringing means emi related issues and self turn on risk – Alison Jan 24 '23 at 07:21
  • The dV/dt rating has to do with capacitance inside the device itself (specifically, turn-on of the parasitic BJT structure, which causes destructive avalanche-like behavior), it's different from the D-G capacitance turn-on effect between opposite transistors in an inverter. Look, if you're worried about dV/dt, why not just increase the gate drive resistor or something? – Tim Williams Jan 24 '23 at 08:44
  • @TimWilliams, yes i know we can increase value of RGgbut then we have to deal with some extra losses and this somehow compromises the efficiency of inverter – Alison Jan 24 '23 at 09:53

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