Patent ID: 8487798

Claim:
A synthesis method of Sigma-Delta modulator capable of relaxing circuit specification and reducing power consumption, comprising the following steps: (a) set a target bandwidth and a target performance; (b) select a filter type and a Sigma-Delta modulator configuration type, and set initial values of a plurality of parameters, to obtain a Noise Transfer Function (NTF) of said Sigma-Delta modulator, and perform coefficient synthesis a first time, so as to ascertain a plurality sets of first performance results corresponding to said Noise Transfer Function (NTF); (c) analyze a plurality of circuit non-ideal effects of said first performance result, to obtain a plurality sets of first circuit specifications fulfilling said target performance; (d) raise an oversampling ratio of parameters based on said first performance result, to increase system ultimate performance; (e) increase attenuation quantity of said Noise Transfer Function (NTF) to make said system ultimate performance greater than said target performance, and perform coefficient synthesis a second time to obtain a plurality sets of second performance results and a plurality of corresponding coefficient values of said parameters; (f) analyze a plurality of circuit non-ideal effects of second performance results, to obtain a plurality sets of second circuit specifications fulfilling said target performance; (g) raise said quantizer bit number in said parameter, and increase again said attenuation quantity, so that said system ultimate performance is greater than said target performance, and perform coefficient synthesis a third time, to obtain a plurality sets of third performance results and a plurality of said corresponding coefficient values of said parameters; (h) analyze a plurality of circuit non-ideal effects of said third performance results, to obtain a plurality sets of third circuit specifications fulfilling said target performance; and (i) compare said first, second, and third circuit specifications obtained in steps (c), (f), and (h), to select the one having greatest variation to perform calibrations required.