Modeling modulators for A/D signal conversion

The performance of an SDM is reported to decline by various factors produced during the design and fabrication process. Namely, the nonideal factors are: the limit of the operational amplifier (op-amp) output swing, the finite DC gain of the op-amp, op-amp slew rate, the integrator gain error by mismatching of the capacitor and nonideality of the internal multibit quantizer. In this article we report not only modeling results of the ideal second-order SDM with a multibit quantizer, but also evaluate its performance according to bit number and OSR. In addition, we determine the maximum error limit of the SDM after investigating the influence of the nonideal factors on the performance of the SDM