รายละเอียด : This paper presents a systematic methodology for designing a voltage-mode multifunction biquad filter employing the commercially available active element, LT1228. The proposed topology adopts a three-input single-output (TISO) configuration. The circuit comprises a single LT1228, two capacitors, and three resistors, offering a highly compact design. The TISO biquad filter is capable of providing five fundamental filtering responses: low-pass (LP), band-pass (BP), high-pass (HP), band-reject (BR), and all-pass (AP) responses, within the same circuit architecture. Notably, these responses are achieved without the need for additional inverting amplifiers or reconfigurations of passive components. The parameters of the proposed filter, encompassing the natural (?0) and quality factor (Q), are
