MAGNETIC FIELD SENSOR LINEARIZATION ARCHITECTURE AND METHOD

摘要

A method of processing an output signal and a readout circuit for a magnetic field sensor are disclosed. The purpose of the readout circuit is to generate a digital representation of the magnetic field vector strength. It comprises an input stage for receiving an output signal of the magnetic field sensor; an output stage for outputting a digital output signal corresponding to the sensor output signal; and an analog to digital conversion circuit. The analog to digital conversion circuit receives the sensor output signal and performs, in sequence, a fast conversion process for calculating a number of most significant bits of the digital output signal corresponding to the sensor output signal and for generating a compensation signal, and a delta sigma based conversion process for calculating at least one least significant bit of the digital output signal. The compensation signal is fed back to the sensor input for linearization. The delta sigma based conversion takes advantage of oversampling and noise shaping to increase resolution.

主权项

1. A readout circuit for a magnetic field sensor, the readout circuit including
an input stage for receiving an output signal of the magnetic field sensor; an output stage for outputting an digital output signal corresponding to the sensor output signal; an analog to digital conversion circuit configured to receive the sensor output signal and to perform, in sequence; a fast conversion process for calculating a number of most significant bits of the digital output signal corresponding to the sensor output signal and for generating a compensation signal to be fed back to the sensor input, and a delta sigma based conversion process for calculating at least one least significant bit of the digital output signal; and a feedback circuit for feeding back the compensation signal to the magnetic field sensor.