Data predictive decision feedback equalizer for position detection in automotive applications
Simon Hainz, Erwin Ofner, Dirk Hammerschmidt, D. Tatschl, Tobias D. Werth · 2005
In automotive application magnetic field sensors are commonly applied for position detection of rotating objects (wind shield wiper, speed, engine applications). Especially engine applications require high accuracy. The main demands for such sensors are correct phase and disturbance (air gap, temperature, noise) immunity. Nowadays sensor-systems follow various hysteresis concepts to avoid jitter. These circuits are robust against noise; however, do not remove jitter introduced by inter symbol interference (ISI). To overcome this problem, a decision feedback equalizer (DFE) was adapted. Based on the standard DFE, a new filter structure is proposed and called data predictive DFE (pDFE). The main advantages of the pDFE are the enhancements in phase detection and the lack of latency in the signal path. This paper explains the new pDFE structure and demonstrates the operation mode with simulations.