Research Of CDBA And Its Filter

Firstly,This paper simply introduces the development and characters of the current-mode circuit, and compares current-mode circuit with voltage-mode circuit; Afterwards, it systematically introduces the principle of current differential buffered amplifiers (CDBA) and current control current differential buffered amplifiers (CCDBA) and their applications in the analog integrated circuit. The main achievements consist of as following aspects:1) A new configuration for realizing CMOS high frequency current differential buffered amplifiers is presented in this paper,compared with the existing CDBA circuits, the proposed circuit in this paper has better frequency characters in bandwidth,and has not limit in the ratio of MOS transistor width and length. In order to verify the circuit performance, theory analyzing and PSPICE simulating of the circuits port character have been done. A second order multifunctional filter is presented; all the results verified the circuits are right. This CDBA model is provided with important significance in circuit design.2) A configuration for realizing n-order current-mode universal filters based on existing CCDBA circuit is presented in this paper. These filters proposed in this paper own many advantages, such as realizing multiple functions simultaneously, adjusting the natural angular frequencyω0 and quality-factor Q independently, lower sensitivities, lower power consumption,and all passive components only having capacitances are earthed, which is convenient for integration. At the same time, PSPICE simulation results verify their performance.3) The paper proposes a configuration for realizing n-order voltage-mode multifunctional filters based on existing CCDBA circuit. These filters not only possess low-pass, band-pass, high-pass and band-stop simultaneously, but also own many advantages, such as adjusting the natural angular frequencyω0 and quality-factor Q independently, lower passive and active sensitivities, and the passive components only have the earthed capacitances. At the same time, PSPICE simulation results verify their performance.