Hall Effect Sensors: Differential vs. TPOS??

[Travman1023]

Can someone explain the differences between a differential hall effect sensor and a TPOS (True Power On Signal) hall effect sensor? Are there any physical construction differences? Or mainly just different circuitry and programming?

I am starting to reverse engineer camshaft and crankshaft sensors and this question has been coming up frequently.

Thank you.

 

[Panther140]

To my knowledge, differential measurements in other applications use some analog method of measuring noise, separate from the raw signal.
The noise signal can be channeled through a shielded wire, into a comparator-- or something with similar capability.
The raw signal is then channeled into another terminal on that same comparator/op amp.
Something mysterious happens within that circuitry, and the difference between the noise channel and the main channel is what gets amplified.

The differential is basically comparing 2 different values, and operates based on the difference of those two values.
Take this info cautiously. I'm no expert. Just trying to help establish clues for you that may help
!