ANALOG TO DIGITAL CONVERSION CIRCUIT WITH AUTOMATIC BIAS POINT DETERMINATION AND MR GRADIENT SYSTEMS USING THE SAME

摘要

A hybrid analog/digital circuit comprises: an analog difference element (60) configured to output an analog difference signal (d) corresponding to a difference between an input analog signal (s meas ) and an analog feedback signal (s bias ); an analog-to-digital converter (ADC) (62) configured to generate a multi-bit digital representation (D) of the analog difference signal; digital control circuitry (64, 66, 68) including at least a digital integrator or digital summer (64), the digital control circuitry configured to generate a digital control signal (S BIAS ) based on the multi-bit digital representation of the analog difference signal; a digital-to-analog converter (DAC) (70) configured to generate the analog feedback signal (s bias ) having an analog value corresponding to a digital value of the digital control signal; and an output unit (72, 74) arranged to output a digital output signal (S MEAS ) equal to or derived from the digital control signal.