Noise Modeling For Charge Amplification and Sampling

A new cyclostationarity-based analytical model for noise analysis of a charge amplifier followed by a correlated double sampling (CDS) circuit is proposed. It determines output noise (power spectral density and squared voltage) resulting from input noise voltages and currents. Model validation is performed by comparing the obtained results with those of temporal noise simulations. This model allows analysis of consequences of CDS and integration duration on noise contributions. It predicts that CDS does not suppress or attenuate effect of input current sources. In the case of 1/f input noise current, the SNR can not be improved by increasing the integration duration.