Amplifier calibration apparatus and method therefor

摘要

An amplifier calibration apparatus for use in an audio device which processes an audio signal. The audio device includes a manual volume control for manually altering the gain of the signal. An amplifier which may include a digital potentiometer serves to alter the gain of the audio signal in response to a control signal. The amplifier calibration apparatus, which serves to automatically calibrate the amplifier, includes a controller; a waveform generator, which generates a known waveform, and a comparator circuit. The known waveform is fed into the amplifier and the resulting amplifier output is fed into the comparator circuit. The comparator compares a constant signal to the amplifier output resulting in a comparison output indicative of any difference between the two signals. The comparison signal is operably connected to the controller such that the controller can calibrate the full scale point of the amplifier.