Patent ID: 8421660

Claim:
A configurable modulator-filter comprising: an analog input that carries an analog input signal; a first sigma-delta modulator loop, receiving the analog input signal, for generating a first loop output, the first sigma-delta modulator loop summing the analog input signal and the first loop output and quantizing a first integration result to generate the first loop output; a first filter-configuring mux, responsive to a first select signal, for generating a first filter input by selecting an input from a first group of inputs that comprises the first loop output, a second loop output, and a third loop output; a second-loop input mux, receiving the analog input signal and the first integration result from the first sigma-delta modulator loop, for generating a second input signal by selecting the analog input signal or the first integration result in response to a second-input select signal; a second sigma-delta modulator loop, receiving the second input signal, for generating the second loop output, the second sigma-delta modulator loop summing the second input signal and the second loop output and quantizing a second integration result to generate the second loop output; a second filter-configuring mux, responsive to a second select signal, for generating a second filter input by selecting an input from a second group of inputs that comprises a fixed signal, the second loop output, and the third loop output; a third-loop input mux, receiving the analog input signal and the second integration result from the second sigma-delta modulator loop, for generating a third input signal by selecting the analog input signal or the second integration result in response to a third-input select signal; a third sigma-delta modulator loop, receiving the third input signal, for generating the third loop output, the third sigma-delta modulator loop summing the third input signal and the third loop output and quantizing a third integration result to generate the third loop output; a third filter-configuring mux, responsive to a third select signal, for generating a third filter input by selecting an input from a third group of inputs that comprises the fixed signal, and the third loop output; and a modified Cascaded-Integrator-Comb (CIC) filter that receives the first filter input, the second filter input, and the third filter input, and generates a filter output, whereby the first, second, and third sigma-delta modulator loops are configurable by select signals to be cascaded in series or to process the analog input signal in parallel.