Noise analysis of a CDS circuit with offset canceling

Correlated double samplers(CDS) are widely used in infrared imaging systems which can suppress 1/f noise effectively. Since the concept was raised, many types of CDS have been constructed whose advantages are different in tradeoff among layout area, speed and power dissipation. This paper presents a method of noise analysis for a CDS that has the function of offset canceling, which starts from the transient noise behavior due to noise models in each clock phase. Then based on the theory of stationary random process, power spectrum density(PSD) of output noise is derived. At last a time domain simulation(TDS) is applied to verify the feasibility of the noise analysis method we proposed, which corresponds well. The proposed method provides a noise estimation method of the CDS through which we can deduce contributions from each noise source to the output noise, moreover whose simulation time is much shorter than that of a TDS.