Method and apparatus for calibration of an electronic device

An electronic circuit having a signal path coupled to receive an operating signal, the electronic circuit producing an output in response to the operating signal, the electronic circuit comprising:

• a calibration excitation signal generator configured to generate a calibration excitation signal;
• a variable transfer function circuit element coupled between the calibration excitation signal generator and the signal path of the electronic circuit, the electronic circuit producing on its signal path a calibration error signal superimposed on the operating signal in response to the calibration excitation signal;
• a calibration error signal detector coupled to the signal path of the electronic circuit for detecting the calibration error signal during normal operation of the electronic circuit;
• and
• a filter circuit coupled between the calibration error signal detector and the variable transfer function circuit element, wherein the filter circuit is configured to generate an adjustment signal operative to adjust the transfer function of the variable transfer function element circuit to minimize the calibration error signal.

A method of calibrating an electronic circuit, the method comprising:

• generating a calibration excitation signal;
• conducting the calibration excitation signal to a signal path of the electronic circuit;
• simultaneously conducting an operating signal of the electronic circuit and the calibration excitation signal on the signal path to responsively generate a calibration error signal on the signal path;
• detecting the calibration error signal on the signal path;
• evaluating the detected calibration error signal;
• and
• adjusting a variable transfer function circuit element in the signal path in accordance with the evaluation of the detected calibration error signal so as to minimize the calibration error signal.