Digital feedforward sigma-delta modulator in analog-to-digital converter and modulation method thereof

A digital feedforward sigma-delta modulator (SDM) for performing digital feedforward sigma-delta modulation on an analog input signal and outputting a corresponding digital output signal, the modulator comprising:

• a plurality of integrators connected in series, receiving an analog signal, integrating the received analog signal and outputting a corresponding analog signal, respectively;
• a plurality of multipliers weighting the analog signals outputted from the plurality of integrators and outputting a weighted analog signal, respectively;
• a plurality of quantizers performing quantization on the analog signals outputted from the plurality of multipliers and outputting a digital signals, respectively;
• a digital adder adding up the digital signals outputted from the plurality of quantizers, subtracting a signal inputted as a feedback signal from the result of the adding up the digital signals, and outputting a corresponding digital output signal;
• and
• a second multiplier weighting the digital signal outputted from the digital adder and outputting the weighted digital signal to the digital adder.

A digital feed-forward sigma-delta modulation method for performing digital feed-forward sigma-delta modulation on an analog input signal and outputting a corresponding digital output signal, the method comprising:

• inputting an analog input signal to a plurality of integrators connected in series;
• weighting the analog input signal and an analog signal outputted from each of the plurality of integrators, and outputting corresponding analog signals;
• quantizing by plurality quantizers the weighted analog signals and outputting corresponding digital signals;
• and
• adding up the digital signals and outputting a corresponding digital output signal.

A digital feed-forward sigma-delta modulation method for performing digital feed-forward sigma-delta modulation on an analog input signal and outputting a corresponding digital output signal, the method comprising:

• inputting an analog input signal to a plurality of integrators connected in series;
• weighting the analog input signal and analog signals outputted from the plurality of integrators, and outputting corresponding analog signals;
• quantizing by plurality quantizers the weighted analog signals and outputting corresponding digital signals;
• and
• adding up all the digital signals and outputting a corresponding digital output signal, and in this case, a signal, fed back after it is obtained by weighting the digital output signal, is applied as a subtraction value when the digital signals are all added up.