| Abstract |
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Higher order Delta-Sigma Modulator (DSM) is basically an unstable system. The approximate conditions for stability cannot be used for the design of a DSM for industrial applications where risk is involved. The conventional second order, single stage, single bit, unity feedback gain , discrete DSM cannot be used for the normalized full range (-1 to +1) of input signal since the DSM becomes unstable when the modulus of the input signal is above ?0.55. The stability is also not guaranteed for amplitude of input signal less than ?0.55. In this proposal, the conventional second order DSM is modified with input signal dependant feedback path gain. The proposed DSM is suitable for industrial applications where one needs the digital representation of the analog input signal, during each sampling period. This first configuration of proposed DSM can operate for the full range of input signal without causing instability. In order to improve the SNR of first configuration, it is combined with conventional second order DSM and proposed the second configuration of DSM. |
