New CMOS balanced output transconductor and application to GM-C biquad filter

A new CMOS voltage controlled balanced output transconductor (BOTA) is introduced. Application of the CMOS BOTA in realizing mixed-mode filter implementation featuring electronic tunability is presented. The filter realizes second order lowpass, bandpass, highpass, allpass and notch responses. The proposed filter architecture uses grounded capacitors and allows modifying the quality factor without changing the center frequency. PSpice simulations are given to confirm the theoretical analysis.