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Frequency Module IGBT

aless2056

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Guys, a question that I believe is simple.

An IGBT module, which has 2 IGBT transistors, such as the MII75-12A3.

When you say in the datasheet that the maximum switching frequency is 30KHz, is that information from the module or from each transistor?

As an example, if the datashhet says it is 30KHz, can I switch each transistor at 30KHz, in total it will be 60KHz or each transistor at 15KHz, in total it will be 30KHz?
 

KlausST

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Hi,

I assume you did not draw a sketch (with signal informations) about what you want to achieve.
Do this, so we can see where you want to connect the 30kHz and where you expect 15kHz and/or 60kHz.

Often with the help of the sketch ... the question is already answered.

Klaus
 

FvM

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I can't imagine many configurations where the switching frequency per module is higher than per transistor, anyway the datasheet specification is surely per transistor. But the number gives only a rough idea of achievable performance, need to analyse the switching and conduction losses of your actual application.
 

Easy peasy

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either or both IGBT's turn on and off 30,000 times per sec ....

- - - Updated - - -

normally for a series totem pole of igbt's one is on when the other is off and vice versa - else you will short the supply - hence each can switch at 30kHz, with a typ 48% ON time ...
 

aless2056

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I'm imagining an H bridge, formed by 2 modules, in which the load will have a maximum 50KHz switching, so, if I use a 30KHz module, each transistor can switch up to 30KHz, correct?

In case each transistor of the module will switch at 25KHz, correct?
 

FvM

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Not sure how you calculate "load switching" frequency. In case of unipolar modulation scheme, output pulse frequency is double the PWM frequency. But that's not relevant for transistor switching losses.
 

aless2056

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My main question is whether the information in a datasheet of an IGBT module is for the module as a single item, or is it for each transistor?

When I read a datasheet of this I consider it to be for each transistor, correct?
 

Easy peasy

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in an H bridge, generally each switch switches at the switching freq, in your case each will do 50kHz max, draw it out and you will see ...
 

FvM

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30 kHz is no exact specification, it's an estimated value that can be achieved unter certain conditions. If you make a quick calculation of switching losses, you'll realize that 30 kHz can't be achieved with full rated current und voltage.
 

aless2056

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Okay, my question since the beginning was if the frequency values in a datasheet, were related to the module or to each transistor.

But it was clear that the values refer to the individual transistors.
 

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