Patent ID: 7760014

Claim:
A differential biquad filter gain stage comprising: a positive single ended circuit and a negative single ended circuit, each including: first and second power supply terminals; a main transistor having a control terminal, and first and second main terminals; a single output terminal coupled to the control terminal of said main transistor; first and second conductances coupled between the first power supply terminal and the control terminal of the main transistor; a first capacitor coupled between the control terminal of said main transistor and the second main terminal of the main transistor of the other single ended circuit; a second capacitor coupled between a node between said first and second conductances and the second main terminal of said main transistor, the first main terminal of said main transistor being further coupled to a node between said first and second conductances of the other single ended circuit; and a first biasing current source operatively coupled to the other single ended circuit to bias said other single ended circuit; and a polarity capacitor having first and second terminals, the first terminal of the polarity capacitor being coupled to the second main terminal of the main transistor of the positive single ended circuit and the second terminal of the polarity capacitor being coupled to the second main terminal of the main transistor of the negative single ended circuit.