SC and SI filters in baseband applications: A comparison

Based on measurements of two IC chips, a comparison between switched-capacitor (SC) and switched-current (SI) bandpass filters is presented. The filters are sampled with clock frequencies up to 10MHz and the nominal center frequency omega(p) is 500kHz with a pole-Q of 10. The focus of the presentation is on implementation issues, such as low voltage supply operation and PSRR. It is shown that in the SI case the design can be made independent of the modulation index in, which results in superior circuit behavior for large input signals. The application under consideration is in telecommunications where analog filtering tasks often take place in the baseband.