High order CMOS differential difference current conveyor universal filter using analytical synthesis technique

In this paper, a high order universal filter using the analytical synthesis technique is proposed. This technique translates the voltage mode transfer functions to active blocks. The filter is constructed using Differential Difference Current Conveyor (DDCC) active blocks. Using the analytical synthesis technique with DDCC active blocks together ensures having a minimum number of active blocks and grounded elements. The proposed nth order universal filter uses only n+1 DDCC, n grounded capacitors, and n+2 grounded resistors. As an example, a 4^th order universal filter is realized and simulated to validate the different frequency responses of this filter using LT-Spice 90nm CMOS technology and a supply voltage of ±0.5V.