Real-Time Programmable Low-Power SC Bandpass Filter

A real-time programmable switched-capacitor (SC) 2nd order bandpass filter is presented. It is based on voltage inverter switch (VIS) principle using inverse recharging devices. These devices are realized with dynamic amplifiers in order to achieve low power dissipation. The filter contains only grounded or virtually grounded network capacitances and therefore it is insensitive to the parasitics between the bottom plates of the implemented MOS capacitors and the substrate. It offers digital programming capability (two Q-factors and three center frequencies) and low power dissipation (185 μW at sampling frequency 8 kHz and power supply voltage 10 V). The filter has been integrated in standard CMOS metal-gate technology.