Unified floating immittance emulator based on CCTA

In this paper, a unified floating immittace emulator based on Current Conveyor Transconductance Amplifier (CCTA) is put forward. It uses two CCTAs, two additional components (two MOS based resistors/one capacitor and one MOS based resistor) and four MOS switches. It can realize both positive and negative floating immittances through appropriate setting of switches. The proposed topology does not require any component matching, thus making it suitable for integration viewpoint. Further, the immittance may be tuned electronically via bias current of CCTA. Additionally, the operation in fractional domain also investigated. The impact of parasitics of CCTA on the performance of the proposed circuit is mathematically formulated. The functionality of the proposed circuit is verified through post layout simulations carried out using the netlist extraction from the layout and examined through SPICE simulations using 90 nm process parameter. The area of the layout of proposed unified immittance emulator is 67.80 μm × 22.80 μm. The proposed immittance circuit is used to implement notch filter, fifth order low pass filter, and capacitance cancellation circuit.