Improving design of the 2nd order high pass sigma delta modulation

Analog to digital conversion have been widely used in the measurement, telecommunications, digital signal processing. Sigma delta modulation is a digital signal processing, or a method for encoding analog signals into digital signals as found in an ADC with high resolution and low cost. Through the use of over sampling and feedback, the quantization error which is suppressed in a narrow band signal at the output of the modulator an analog-to-digital converter based on the sigma delta modulation is capable of providing a very high resolution (HPSDM). This Paper describes the theory and design of continuous-time (CT) HPSDM for A/D conversion. The essential idea of the work is the design of the 2^nd order HPSDM and get the output using fast Fourier transform (FFT)by an applied software.