Patent ID: 7109786

Claim:
A biquad notch filter comprising: first and second power supply terminals; an input terminal; a transistor having a control terminal, and first and second main terminals; an output terminal; a first stage including first and second admittances of a first type connected to each other at a node and connected between said input terminal and the control terminal of said transistor, a first current source connected between said first power supply terminal and the first main terminal of said transistor, a second current source connected between the second main terminal of said transistor and said second power supply terminal; a third admittance of a second type connected between the control terminal of said transistor and said second power supply terminal; a fourth admittance of said second type connected between the node between said first and second admittances on one hand and said second main terminal of said transistor on another hand; and a second stage including a transconductance, which comprises a fifth admittance of said first type and which is connected between the control terminal of said transistor and said output terminal, a sixth admittance of said first type connected between said output terminal and said second power supply terminal, and a connection of said first main terminal of said transistor to said output terminal.