| An anti-aliasing filter that incorporates a sampler is proposed. Its architecture is inspired by the anti-aliasing filtering property of continuous-time (CT) DeltaSigma modulators. However, contrary to CT DeltaSigma modulators, the proposed sampling anti-aliasing filter is not sensitive to clock jitter. Furthermore, its key characteristics include: (1) high suppression of aliases---for example, compared to a Butterworth filter of the same order---owing to its notches at multiples of the sampling frequency; (2) high-pass shaping of sampling errors, similar to the shaping of quantization noise in DeltaSigma modulators; and (3) its alias suppression is preserved over a broad range of sampling frequencies, thereby enabling its use as a general-purpose intellectual property (IP) block. Thus, the proposed sampling anti-aliasing filter is particularly attractive at the input of noise-shaping analog-to-digital converters (ADCs), such as discrete-time (DT) DeltaSigma ADCs. Its performance advantages are derived theoretically and confirmed through simulations. |
