Analytical Synthesis of Digitally Programmable Versatile-Mode High-Order OTA-Equal C Universal Filter Structures with the Minimum Number of Components

High-Order OTA-Equal C Universal Filter Structures with the Minimum Number of Components Chun-Ming Chang, Senior Member, IEEE, Jen Hung Lo*, and Li-Der Jeng* Dept. of Electrical/Electronic* Engineering, Chung Yuan Christian University, Chung-Li, Taiwan 320, R. O. China E-mail: [email protected] Abstract: How to simultaneously involve and merge four distinct kinds of modes, i.e., voltage, current, trans-admittance, and trans-impedance modes, into an analytical synthesis method (ASM) for synthesizing a complicated versatile mode high-order universal (namely, low-pass, band-pass, high-pass, band-reject, and all-pass) filter transfer function is presented in this paper employing (i) all single-ended-input operational transconductance amplifiers (OTAs), (ii) all grounded capacitors, and (iii) the minimum number of active and passive components. The new filter structure enjoys the important merits of digital programmability and low sensitivity in addition to have a controllable gain (except the current-mode one), cascadable voltage input and current output terminals, and the absence of the need to impose component matchings. H-spice frequency-dependent simulation results, using TSMC 0.18μm process and ±0.9V supply voltages, demonstrate precise filtering responses (for example, the current-mode high-pass response has only 0.3% error) at the operating frequency, 10 MHz.