Greg,
If you mean one chip with no support components, I don't recall seeing one of those. But you do just mean for sensing phase rotation on the input rather than shaft rotation, don't you?
I've repaired a Time-Mark PLM within the last couple of years and the circuit was fairly simple. By the time I was repairing disk drives, they were all single phase units. I remember the 5KW transmitters I used to install or service having a PLM to make sure the blower motor wasn't running the wrong way. That would've sucked.
Joe
