| 摘要 |
A method of gain calibration of an ADC stage is disclosed. The method comprises receiving an input analog signal, converting the input analog signal into an m-bit digital signal by means of an analog to digital converter, generating a calibration signal by means of a random number generator, adding the calibration signal to the m-bit digital signal to produce an adjusted m-bit digital signal, converting the adjusted m-bit digital signal into an adjusted partial analog signal by means of a digital to analogue converter, subtracting the partial analog signal from the input analog signal, to produce a residual analog signal, amplifying the residual analog signal. The method is characterised in that the calibration signal may take any one of three values. In a preferred embodiment, the calibration is constrained to one of only two of these three values, when the input signal is in an outermost sub-range. An ADC stage adapted to operate according to the method is also disclosed. |
