split personality inductor

They may show the part being used in six different ways, which is scarcely unusual - op amps data sheet tend to show them being used in different ways in different applications.

It may reflect that fact that inductors are complicated devices and many of the people who use them haven't worked out the implications of the transformer equations, which seem to be hard to get into the heads of undergraduates. They don't seem to show up in The Art of Electronics, and I first came across them in the Siemens ferrite core application notes, and found myself spelling out the implications to an equally senior electronic engineer when I was in my late forties.

John Larkin seems to have been frightened by a transformer when young, and much prefers to buy them off the shelf rather than thinking about getting them wound for specific applications.

An old discussion, about matching differential slew rates, had a suggestion of feeding the differential signals into a heavy termination load, through a 1:1 transformer; it could just as easily (in that application) be called a common-mode filter, except that you'd want it to PASS high frequencies, and some common-mode filters are deliberately lossy.

Matching dI/dt amplitudes (but with one negative and one positive) into a resistive load is one way to get symmetric dV/dt .