High-order Chebyshev Notch Filter based on MO-OTA and its application in Biosensor

This paper presents a high-order notch filter based on multiple output OTA (MO-OTA). The signal flow graph (SFG) method is applied as a design procedure based on the RLC prototype. The RLC Chebyshev low-pass filter is used as an original prototype. The network transform is applied to convert the LPF to a notch filter. From the SFG, the denormalized network can be replaced by integrators and differentiators. The current-mode lossy and lossless types of integrator and differentiator are realized by using CMOS MO-OTA and grounded capacitor. A simple and low-complexity structure is achieved and constructed by 9 MO-OTAs and 6 grounded capacitors. The stop-band frequency between 10Hz-1kHz can be electronically tuned by the bias current between 1-100 μA. The low power supply ±0.75V is required which consumes the power 15mW at 100μA bias current. An application in ECG signal with power line interference (PLI) removal is included.