On the design of 2nd order multi-bit /spl Delta//spl Sigma/-modulators

The design aspects of multibit /spl Delta//spl Sigma/-modulators are discussed. The loop filter design of a 2nd order multibit modulator is covered in more detail with the emphasis on the optimisation of the dynamic range and the trade-off between SNR and the power consumption. It is shown with behavioural level simulations that the peak SNR is reached with an overloaded quantizer and that an aggressive loop filter tends to increase the power consumption of the amplifiers.