Comunicación presentada al "ISCAS'99" celebradao en Orlando (USA) en Julio de 1999.This paper presents a systematic analysis of the major switched-current (SI) errors and their influence on the quantization noise shaping of SI BandPass SD Modulators (BPSDMs). Closed form equations are provided for the degradation of the signal-to-noise ratio and for the change of the notch frequency position in order to facilitate the design of this class of modulators. All these results have been validated by non-ideal time-domain behavioral simulations.This work has been supported by the Spanish CICYT Project TIC 97-0580.Peer reviewed