Design and Comparison of 1st Order and 2nd Order Analog Delta Sigma Modulators

The delta sigma modulators presented in this paper include the popular switched capacitor integrator (SCI) and MOSFET models of level 7, popularly known as the BSIMv3 model. The 1st order and 2nd order delta sigma modulators are designed with two different models and they output a pulse proportional modulated signal in response to the input of an analog signal. It is observed that the 2nd order delta sigma modulator provides better stability and noise immunity over the 1st order delta sigma modulator. The NMOS models behave same for the 1st order delta sigma modulator but variations are observed for 2nd order delta sigma modulators.