High dynamic range preconditioning circuit with noise cancellation for fully differential, class AB log-domain filters

An architecture performing pre-distortion of the input signal fed to fully differential, class AB log-domain filters is suggested. The architecture performs noise cancellation and increases the maximum allowed input swing. All previous published fully differential, class AB log-domain filters are expected to benefit from the proposed topology. The dynamic range is increased 8.1 dB from 53.1 dB in the classical circuit to 61.2 dB in the proposed architecture when consuming 15.7muW and 19.1muW respectively. The increase in dynamic range is obtained with the penalty of 22% increase in the quiescent power consumption