Programmable receivers including a delta-sigma modulator

A programmable delta-sigma modulator, comprising:

• a first channel configured to receive an in-phase signal and including a first delta-sigma loop filter;
• and
• a second channel configured to receive a quadrature signal and including a second delta-sigma loop filter;
• each of the first delta-sigma loop filter and the second delta-sigma loop filter comprising:
• an integrator;
• a quantizer having an input coupled to an output of the integrator;
• a summing node having an output coupled to an input of the integrator;
• a feedforward path from an input of the delta-sigma loop filter to a first input of the summing node;
• and
• a first feedback path from an output of the quantizer to a second input of the summing node;
• and
• at least one cross-coupling path between the first delta-sigma loop filter and the second delta-sigma loop filter, the at least one cross-coupling path including one or more programmable coefficients for configuring the programmable delta-sigma modulator in a low-pass mode or a quadrature mode.

A programmable receiver, comprising:

• an analog module comprising a programmable delta-sigma analog-to-digital converter (ADC), the delta-sigma ADC comprising:
• first and second channels, each of the first and second channels including a loop filter;
• at least one first cross coupling path coupling the first channel to the second channel;
• and
• at least one second cross coupling path coupling the second channel to the first channel, each of the at least one first cross coupling path and the at least one second cross coupling path including a programmable coefficient and a multiplexer for switching a polarity of the programmable coefficient;
• and
• a digital module including a digital filter coupled to an output of the delta-sigma ADC.

A quadrature delta-sigma analog-to-digital converter (ADC), comprising:

• a first channel configured to receive an in-phase signal and a second channel configured to receive a quadrature signal, each of the first channel and the second channel including:
• a first integrator;
• a first summing node having a first input coupled to an input of the channel and an output coupled to an input of the first integrator;
• a second summing node having a first input coupled to an output of the first integrator;
• a second integrator having an input coupled to an output of the second summing node;
• a quantizer having an input coupled to an output of the second integrator;
• an input-feedforward path from the input of the channel to a second input of the second summing node;
• and
• at least one feedback path coupled from an output of the quantizer to at least one of the first summing node and the second summing node;
• and
• at least one additional feedback path coupled from an output of the second integrator to the first summing node and including a programmable coefficient.