VOLTAGE TYPE FIRST ORDER ALL-PASS FILTER EMPLOYING FULLY DIFFERENTIAL CURRENT FEEDBACK OPERATIONAL AMPLIFIER AND QUADRATURE OSCILLATOR

Abstract

An improvement voltage mode first order all-pass filter configuration is proposed. The presented circuit uses a single fully differential current feedback operational amplifier (FDCFOA), resistors and a grounded capacitor. High input impedance of the proposed filter enables the circuit to be cascaded without additional buffers. It does not impose any component matching constraint in analog signal processing circuits. Also higher order all-pass filter could be achieved by cascading the proposed all-pass sections. In order to demostrate the performance of the proposed filter a new voltage mode oscillator is introduced as an application example. Furthermore the theoretical results are verified with SPICE simulations using a CMOS realization of FDCFOA

Keywords

• All-pass filter, fully differential current feedback operational amplifier, analog integrated circuits, quadrature oscillator.

Abstract

Gerilim modunda birinci dereceden tüm geçiren yeni bir süzgeç devresi önerilmiştir. Önerilen devrede bir tam diferansiyel akım geribeslemeli işlemsel kuvvetlendirici, dirençler ve topraklı bir kapasite bulunmaktadır. Önerilen devrenin yüksek giriş direnci, ek tampon kullanılmadan devrenin kaskad bağlanabilmesini sağlamaktadır. Analog işaret işleme devrelerinde herhangi bir eleman denkleştirme koşuluna gerek duyulmamaktadır. Aynı zamanda daha yüksek dereceden tüm geçiren süzgeçler önerilen birinci dereceden süzgeçler kaskad bağlanarak elde edilebilmektedir. Önerilen süzgecin başarımını göstermek amacıyla, bir uygulama örneği olarak gerilim modunda yeni bir osilatör tanıtılmıştır. Bundan başka teorik sonuçlar, FDCFOA elemanının CMOS gerçeklenmesi kullanılarak SPICE benzetimleriyle doğrulanmıştır.

Keywords

• Tüm geçiren süzgeç, tam farksal akım geribeslemeli işlemsel kuvvetlendirci, analog tümdevreler, quadrature osilatör

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