Patent ID: 6873281

Claim:
A method of canceling quantization noise in an ADC, comprising: sampling an analog signal provided to a first delta-sigma modulator to produce a sampled analog input signal; generating a sampled analog error signal from the difference of said analog input signal and a DAC output; integrating said sampled analog error signal to produce a first integrated error signal; summing a test signal with the first integrated error signal and quantization noise produced by said first delta-sigma modulator; generating, as an output, a first noise signal comprising the quantization noise test signal using said integrated error signal; estimating an even sample NTF corresponding to even samples of the sampled analog input signal; estimating an odd sample NTF corresponding to odd samples of the sampled analog input signal; forming a composite estimated NTF that includes said even and odd estimated NTFs; and subtracting said composite estimated NTF filtered noise from an analog NTF filtered noise from said first delta-sigma modulator.