free wheel diode

[Jonas]

Hi

I wonder how I shall choose a correct freewheel diode. Which
parameters are necessary to consider?

Thanks
Jonas

 

[Fred Abse]

Hi

I wonder how I shall choose a correct freewheel diode. Which
parameters are necessary to consider?

If, as I suspect, it's going in parallel with a transistor, the same
voltage and current as the transistor is a good guesstimate.

 

[GPG]

Assuming you are talking about fly back switching. the same as the
switch, the correct TYPE of diode is important.

 

[Fritz Schlunder]

Hi

I wonder how I shall choose a correct freewheel diode. Which
parameters are necessary to consider?

Thanks
Jonas

Usually the most important parameters to keep in mind are the voltage
rating, current rating, reverse recovery speed/reverse recovery charge,
average power dissipation, and maximum peak die temperature (under both
normal and reasonably anticipated transient conditions).

Generally speaking if any of the above listed items aren't properly
accounted for in your selected diode, the device will likely end up
destroyed.

Once you have the above parameters satisfactorily covered, then you can
further optimize your diode selection by considering some other parameters
such as: forward voltage, minimum EMI radiation, reverse leakage current,
packaging/size, cost, availability, etc.

Usually in low voltage (IE: <100V) applications schottky diodes make for
good freewheeling diode choices.