History and progress of the Tow-Thomas bi-quadratic filter. Part I. Generation and op AMP realizations
The history of Tow-Thomas second-order filter is reviewed. Two alternative generation methods of the Tow-Thomas filter are discussed. The first is a generation method from the second-order passive RLC filter and the second is from the multiple feedbacks inverting low-pass filter using a single op amp. Several forms of the circuit are briefly reviewed. Passive and active compensation methods to improve the circuit performance for high-Q designs are summarized. Spice simulation results are included.
tow-thomas filter active filters operational amplifier circuits