Biquadratic transconductance switched capacitor filters

The author presents a new type of sampled data filters consisting of transconductance, switches, and capacitors, called transconductor switched capacitor (TSC) filters. The implementation of this type of filter is particularly suitable for the CMOS integrated circuit technologies. The synthesis of biquadratic TSC filters is explained based on a signal flow graph realizing the general z-domain second-order transfer function. The filter coefficients are determined by the clock pulse width and the transconductances, both of which can be turned, and the integrator capacitors. By an appropriate choice of the clock pulse width the silicon area consumed for the transconductors and the capacitors can be optimized