Real-time programmable low power SC bandpass filter

A real-time programmable switched capacitor (SC) second-order bandpass filter is presented. It is based on the 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 parasitic capacitances between the bottom plate of the implemented MOS capacitors and the substrate. The circuit offers digital programming capability (two Q factors and three center frequencies) and low power dissipation (185 μW at a sampling frequency of 8 kHz and with a power supply voltage of 10 V). The filter has been integrated in CMOS metal-gate technology.