A biquadratic switched-capacitor filter having a non-inverting input terminal, an inverting input terminal, a non-inverting output terminal, and an inverting output, terminal, the biquadratic switched-capacitor filter comprising:
- an operational amplifier having a non-inverting input, an inverting input, a non-inverting output, and an inverting output;
- a first switched-capacitor circuit, controlled by a first clock signal and a second clock signal, coupled between the inverting input terminal of the biquadratic switched-capacitor filter and the inverting input of the operational amplifier;
- a second switched-capacitor circuit, controlled by the first clock signal and the second clock signal, coupled between the inverting input terminal of the biquadratic switched-capacitor filter and the inverting input of the operational amplifier;
- a third switched-capacitor circuit, controlled by the first clock signal and the second clock signal, coupled between the non-inverting input terminal of the biquadratic switched-capacitor filter and the non-inverting input of the operational amplifier;
- a fourth switched-capacitor circuit, controlled by the first clock signal and the second clock signal, coupled between the non-inverting input terminal of the biquadratic switched-capacitor filter and the non-inverting input of the operational amplifier;
- a fifth switched-capacitor circuit, controlled by the first clock signal and the second clock signal, coupled between the inverting input of the operational amplifier and the non-inverting output of the operational amplifier;
- a sixth switched capacitor circuit, controlled by the first clock signal and the second clock signal, coupled between the non-inverting input of the operational amplifier and the inverting output of the operational amplifier;
- a seventh switched-capacitor circuit, controlled by a third clock signal and a fourth clock signal, coupled between the inverting output of the operational amplifier and the inverting input of the operational amplifier;
- an eighth switched-capacitor circuit, controlled by a fifth clock signal and a sixth clock signal, coupled between the inverting output of the operational amplifier and the inverting input of the operational amplifier;
- a ninth switched-capacitor circuit, controlled by the third clock signal and the fourth clock signal, coupled between the non-inverting output of the operational amplifier and the non-inverting input of the operational amplifier;
- a tenth switched-capacitor circuit, controlled by the fifth clock signal and the sixth clock signal, coupled between the non-inverting output of the operational amplifier and the non-inverting input of the operational amplifier;
- a first feedback capacitor, coupled between the non-inverting output of the operational amplifier and the inverting input of the operational amplifier;
- a second feedback capacitor, coupled between the inverting output of the operational amplifier and the non-inverting input of the operational amplifier;
- a first switching device, controlled by the second clock signal, coupled between the non-inverting output of the operational amplifier and the non-inverting output terminal of the biquadratic switched-capacitor filter;
- and
- a second switching device, controlled by the second clock signal, coupled between the inverting output of the operational amplifier and the inverting output terminal of the biquadratic switched-capacitor filter;
- wherein the first clock signal and the second clock signal are two-phase, complementary but non-overlapping pulse trains with a reference period, the third clock signal is a pulse train with double the reference period and coincident with the first clock signal, the fourth clock signal is a pulse train that results from delaying the third clock signal by half the reference period, the fifth clock signal is a pulse train that results from delaying the fourth clock signal by half the reference period, and the sixth clock signal is a pulse train that results from delaying the fifth clock signal by half the reference period.