Second-Order Mixed-Mode Multi-Input Single-Output Universal Filter Using Three Current Feedback Operational Amplifiers

Abstract

This paper illustrates the practical application of a mixed-mode universal filter (MMUF) circuit employing three current feedback operational amplifiers, two grounded capacitors, and three to five resistors. In other words, the current-mode (CM) filter selection uses three resistors, the transadmittance-mode (TAM) and transimpedance-mode (TIM) filter choices need four resistors, and voltage-mode (VM) one includes five resistors. However, one resistor-matching constraint is required for the all-pass and notch filter responses of the CM, TIM, VM, and TAM filters. Also, two resistor-matching constraints exist for the high-pass filter responses of the CM and TIM filters. 0.13 mu m IBM CMOS technology parameters and supply voltages of +/- 0.75 V are used in the SPICE simulations. Numerous experimental investigations corroborate the theory.