DRV421: Recommended coil

Hello Javier,

Thank you for your reply.
I am sorry for the delay.
I understood that there is no magnetic module SC2912(SUMIDA) for DRV 421 EVM.
I want to run the EVM as soon as possible,I will consider other methods.

Best regards,
Seishin

Hello Seishin,

If you are needing this for low frequency (<1kHz) you may be able to get a manufacture to use laminated steel plates are normally used in transformers to make you a core that can quickly be cut to your specifications.  If you are needing a higher frequency you may need a ferrite core that can function at higher frequencies and will require manufacturing that would require more time and cost. 

I have experimented with core that I bought off the shelf and cut them myself.  If you go that route there are some concerns.  Normally the core material is very brittle and can break you need to be careful when cutting.  Another issue is winding the core with the compensation coil.  I have done this and another customer has done this with success.  The customer had a method for winging the core, and I did not and did it manually.  The DRV421 needs an inductance greater than 0.1H and recommended between 0.3H and 2H.  So the combination of core size, number of windings, and size of air gap(smaller is better) you are able to provide will determine this.  I can simulate a core dimensions and windings to determine the inductance created by your core design just give me the dimensions, # windings, and core material type.

Hope this helps.