I have searched the internet for Entmagnetisierchip and Feldentladungschip, but could not come up with a single hit (which goes to show that these terms are really not used a lot - if at all). However, your question intrigued me and I consulted with an electronics engineer. My resulting search revealed the term I propose above . It makes no reference to the fact that it may be a chip of some sort, but it describes its function quite well. A Google search revealed numerous hits for your context.

Another idea may be: Entmagnetisierdrossel, but that could be too specific. It is not really a chip but it is used to remove the charge buildup from diskettes, cd-roms, tapes etc.