Patent ID: 8791847

Claim:
A sigma delta modulator, comprising: a first input circuit that receives an analog signal and provides an intermediate signal and a first quantizer signal; a first quantizer that receives the first quantizer signal and provides a first quantizer output; a first output circuit that has an input that receives the first quantizer output and provides a first processed signal to a summer; a second input circuit that receives the intermediate signal and provides a second quantizer signal; a second quantizer that receives the second quantizer signal and provides a second quantizer output; and a second output circuit that has an input that receives the second quantizer output and provides a second processed signal to the summer, wherein the first quantizer comprises: a programmable reference voltage circuit having a first reference output and a negative of the first reference output; a first comparator having a first input coupled to the first quantizer signal, a second input coupled to the first reference output, and an output as a first portion of the first quantizer output; and a second comparator having a second input coupled to the first quantizer signal, a second input coupled to the negative of the first reference output, and an output as a second portion of the first quantizer output.