A Non-Linearity Digital Background Calibration Algorithm with Piece-Wise Linear Functions

In this paper, a novel background calibration algorithm for amplifier non-linearity is proposed. This algorithm utilizes piece-wise linear function (PWL) to compensate gain compression caused by non-linearity. Non-linearity is extracted by distribution based method with no restriction on the input's distribution. The algorithm is employed to an amplifier whose non-linearity is extracted from circuitry simulation. A total harmonic distortion (THD) reduction of 24.98 dB is observed with half full-scale input. The maximum and root mean square (RMS) error between calibrated amplifier and ideal linear system are reduced to 3.76e-04 and 2.04e-04, which are 3.31% and 4.79% of their uncalibrated value.