Reverse Recovery Time Trr of new FERD rectifiers family ?

[Central SUPPORT]

From an ST newsletter I understood that ST is promoting new FERD diodes as "rectifiers for switching power supply". I could use these new diodes in a new flyback design so I downloaded a couple of datasheets and searched for Reverse Recovery Time Trr and Reverse Recovery Charge Qrr parameters but was not able to find them. Did you forget to list them or did I miss something?

NOTE: This question and answer originated from a customer support case which was handled by us. We regularly review support cases and add any helpful ones here for all to benefit from.

[Central SUPPORT · Accepted solution]

Reverse recovery parameters are considerable for bipolar diodes like ST's Ultrafast rectifiers. But FERD is a Schottky diode type where Trr is not sigificant, i.e. very low.

By the way, for efficiency simulation I would recommend to use our Schottky&FERD eTool which is part of our eDesignSuite web tool (user manual is attached). This will allow you to take a closer look these rectifiers, e.g.

·       analyze and compare typical and maximum electrical characteristics and

·       calculate forward and reverse power losses with current and voltage waveform function of junction temperature. 

[KHeyer]

Hi,

Can you please provide a numerical range of Trr? Not significant and very low are not useful.

If a specific part helps, could you provide a Trr for FERD30SM100DJF?

Cheers,

Kevin

[Peter BENSCH]

As with Schottky diodes, a time period trr is not determined by internal processes (e.g. removal of charge carriers), but mainly by external influences, e.g. inductance and capacitance of the leads forming an LC circuit. As these external influences are not part of the FERD, their parameters cannot be listed in the data sheet.

You will find some more details while searching the internet using your favourite search engine and terms like e.g. "schottky trr".

Hope that answers your question?

Regards
/Peter