Systems and methods to reduce quadrature error in sensors

摘要

Various embodiments of the invention provide for improved performance by reducing a quadrature error signal. In certain embodiments, this is accomplished by using a mixed-signal architecture comprising analog and digital circuit components in a closed-loop configuration that generates from a detected quadrature error signal a calibration quadrature signal that is then compensated at a virtual ground of an analog front end circuit. Some embodiments allow for pre-calibration for quadrature error and/or adaptive compensation of unwanted drift effects of the quadrature error, including temperature drifts.

主权项

1. A quadrature compensation circuit to reduce quadrature error, the circuit comprising:
a front-end circuit coupled to receive a first signal that comprises a quadrature error component, the front-end circuit outputs an analog signal; a first demodulator coupled to the front-end circuit, the first demodulator demodulates the analog signal and is configured to output a first demodulated signal related to the quadrature error component; a low pass filter coupled to the first demodulator, the low pass filter is coupled to filter out a harmonic signal from the first demodulated signal to generate a DC signal that is representative of an amplitude of the quadrature error; a modulator coupled to receive the DC signal, the modulator is configured to output a modulated DC signal; and a DAC coupled to the modulator, the DAC generates a calibration quadrature signal.