Patent ID: 8604887

Claim:
A current-feedback operational amplifier-based sinusoidal oscillator, comprising: an integrated circuit current-feedback operational amplifier having a first differential input, a second differential input, a slewing node, and an output; an external capacitor connected between ground and the first differential input; and an external resistor connected between ground and the second differential input and between ground and the slewing node; wherein the output oscillates sinusoidally at an oscillation frequency determined by the relation ω 2 = 1 C 1 ⁢ C 2 ⁢ R 1 ⁢ R 2 - 1 4 ⁢ ( 1 C 2 ⁢ R 1 - 1 C 2 ⁢ R 2 - α β ⁢ ⁢ C 1 ⁢ R 1 ) 2 = ω 0 2 - ɛ 3 2 , wherein C 1 is the external capacitor, C 2 =C y +C z ≅6.5 pF, C y is an internal capacitance of the second differential input, C z is an internal capacitance of the slewing node, α/β is a current gain ratio of said CFOA, R 1 is an internal resistance of the first differential input, and R 2 is determined by a combination of the internal resistors at the second differential input, the slewing node, and the external resistor.