Delta-sigma loop filters with input feedforward

A loop filter comprising:

• a first summing node having a first input coupled to an input of the loop filter;
• a first integrator having an input coupled to an output of the first summing node;
• 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 third summing node having a first input coupled to an output of the second integrator;
• a third integrator having an input coupled to an output of the third summing node;
• a quantizer having an input coupled to an output of the third integrator;
• a first input-feedforward path from the input of the loop filter to a second input of the third summing node;
• and
• a second input-feedforward path from the input of the loop filter to a third input of the third summing node.

A device, comprising:

• a digital module;
• and
• an analog module having an output coupled to an input of the digital module, the analog module comprising an analog-to-digital converter (ADC) comprising a delta-sigma loop filter, the delta-sigma loop filter comprising:
• a first summing node having a first input coupled to an input of the delta-sigma loop filter;
• a first integrator having an input coupled to an output of the first summing node;
• 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 third summing node having a first input coupled to an output of the second integrator;
• a third integrator having an input coupled to an output of the third summing node;
• a quantizer having an input coupled to an output of the third integrator;
• a first input-feedforward path from the input of the delta-sigma loop filter to a second input of the second summing node;
• a second input-feedforward path from the input of the delta-sigma loop filter to a second input of the third summing node;
• a third input-feedforward path from the input of the delta-sigma loop filter to a third input of the third summing node;
• a first feedback path from an output of the quantizer to a second input of the first summing node;
• and
• a second feedback path from the output of the quantizer to a third input of the second summing node.