A Q=100 SC bandpass filter

A high-selectivity (Q=100) SC bandpass filter centered at 100kHz is presented. The filter implements a 12th order transfer function whose poles are placed at only two frequencies. This aspects has been exploited in the realization using the cascade of 6 biquad cells. This improves the matching between different cells and, as a consequence, the frequency response accuracy. The filter is realized in a BiCMOS technology (LNMOS=4µm, LPMOS=3µm). For the available 20 samples, the center frequency mean-value error is lower than 0.2%, while the Q mean-value error is lower than 0.2%.