Patent ID: 11946985
Assignee: ALLEGRO MICROSYSTEMS, LLC
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An electronic circuit for measuring an angle and an intensity of an external magnetic field, comprising:
a first magnetic field sensing unit being configured to output a first sensing output signal and a second magnetic field sensing unit being configured to output a second sensing output signal, a first sensing axis of the first magnetic field sensing unit being substantially orthogonal to a second sensing axis of the second magnetic field sensing unit;
a voltage generator configured to supply a synchronization signal having a generator frequency and to supply a first voltage waveform to the first magnetic field sensing unit and a second voltage waveform to the second magnetic field sensing unit; wherein the first and second voltage waveforms have substantially the same amplitude and the same generator frequency, and are phase shifted by about 90° with respect to each other;
a signal conditioning unit into which the first and second sensing output signals are inputted and configured to add the first sensing output signal (301) to the second sensing output signal to obtain a summed signal and output a conditioned signal;
and
a magnetic field angle detection unit, which is configured to receive the conditioned signal and the synchronization signal, and is configured to measure a phase shift between the conditioned signal and the synchronization signal and to determine the angle of the external magnetic field from the measured phase shift;
wherein each of the first and second magnetic field sensing units comprises a magnetic tunnel junction and is configured such that an amplitude of the first and second sensing output signals varies linearly with a variation of the intensity of the external magnetic field, the electronic circuit further comprising a magnetic field intensity detection unit configured to determine the intensity of the external magnetic field by sampling the amplitude of the summed signal at its maximum to obtain a corresponding sampled magnetic field intensity output, the occurrence of the maximum being detected base on the conditioned signal being a digital phase comparator signal of the summed signal.