Method and apparatus for converting an analog signal to a digital signal using an oversampling technique.

摘要

An analogue signal on terminal (1) is sampled by a sampler (11) operating at a rate in excess of Nyquist rate. A locally decoded signal is subtracted in a subtracter (12) to produce an error signal which may be integrated (13) and again have the locally decoded signal subtracted (14) to provide a difference signal to a two-level quantizer (15). The output of the quantizer is integrated by an integrator (16) to provide the locally decoded signal. A Nyquist rate digital signal is provided not from the output of the integrator (16) but by way of another integrator (23) preceded by a sampling frequency converter (22) which converts the output of the quantizer (15) down to an intermediate frequency for digital filtering (20) and re-sampling (21) at Nyquist rate.