Sigma-delta (sigmadelta) analog-to-digital converter (ADC) structure incorporating a direct sampling mixer

A sigma-delta mixer comprising:

• a signal input;
• a sampling circuit that operates in a discrete-time charge domain, coupled to the signal input, the sampling circuit containing circuitry to convert a signal provided by the signal input into a discrete-time sample stream (DTSS);
• a discrete-time processing unit coupled to the sampling unit, the discrete time processing unit containing circuitry to filter the discrete-time sample stream;
• and
• a feedback signal line coupled to the discrete-time processing unit and the sampling unit, the feedback signal line to carry information outputted by the discrete-time processing unit to the sampling unit.