A Performance Prediction Method with an Equation-Based Behavioral Model for a Single-Bit Single-Loop Sigma-Delta Modulator

2. Performance Prediction Issues

Figure 1 shows the proposed prediction flow of SDM performance. According to this flow, the real performance can easily be predicted, and the required specification of the building blocks in SDM can be obtained. First the specifications of SDM, including bandwidth, peak signal-to-noise ratio (PSNR), and maximum input range, should be defined, and then the designer can alter the oversampling ratio (OSR) and fit the required coefficients of the selected architecture according to the stability requirement. To tolerate the performance degradation of SDM as considering all the non-ideal circuit effects (Malcovati et al., 2003), the next step is to create the circuit behavioural model with SIMULINK and individually apply it to the SDM architecture in order to obtain the required circuit specifications. When acquiring the detailed specifications, the non-ideal effects can be integrated into the SDM with consideration of all the non-ideal effects at the same time. Therefore, the real SNR and dynamic range (DR) can be predicted by the proposed integrated behavioral model. According to this procedure, the designers can rapidly predict the real performance before the circuit implementation. If the final simulation results do not match the required system specification, the designers can try to revise the specification in order to tolerate the performance degradation caused by the circuit implementation.

Figure 1.

Prediction flow of SDM performance in circuit implementation