A reduced capacitor spread algorithm for elliptic bandpass SC filters

A modification of a well-known algorithm for simulating elliptic LC ladder filters by switched-capacitor (SC) technique is presented, The filter terminations were realized without damped integrators. The modification was proven useful in reducing the capacitance spread and total capacitance in high-Q bandpass SC filters: improvements by factors of five and six were obtained in the design of sixth- and tenth-order bandpass filters, respectively. A chip, including four sixth-order bandpass filters in the audio range, was designed and found to function properly.