Multi-stage noise shaping analog-to-digital converter

A method for converting an analog input signal to a digital output signal using a multi-stage noise-shaping (MASH) analog-to-digital converter (ADC), the method comprising:

• receiving the analog input signal as input to a loop filter of a front-end delta-sigma modulator for digitizing the analog input signal to produce a first intermediate digital output signal;
• and
• subtracting the first intermediate digital output signal from the analog input signal to obtain an error of the front-end delta-sigma modulator;
• and
• receiving the error as input to a back-end delta-sigma modulator for digitizing the error to produce a second intermediate digital output signal;
• wherein the digital output signal of the MASH ADC is produced from the first intermediate digital output signal and the second intermediate digital output signal.

A cellular base station comprising:

• an antenna for receiving an analog signal in the air;
• a multi-stage noise-shaping (MASH) analog-to-digital converter (ADC) for converting the analog signal to a digital output signal, the MASH ADC comprising:
• a front-end delta-sigma modulator for receiving the analog output signal as input to a loop filter of the front-end delta-sigma modulator and digitizing the analog input signal to produce a first intermediate digital output signal;
• and
• a back-end delta-sigma modulator for receiving an error of the front-end delta-sigma modulator, wherein the error is a difference between the analog input signal and the first intermediate digital output signal, and digitizing the error to produce a second intermediate digital output signal;
• wherein the digital output signal of the MASH ADC is produced from the first intermediate digital output signal and the second intermediate digital output signal.