Resistorless Current-Mode First-Order All-Pass Filter with Electronic Tuning Employing Low-Voltage CBTA and Grounded Capacitor

In this paper, a new realization of a current-mode first-order all-pass filter (APF) using a single active building block (ABB) and one grounded capacitor is presented. As the ABB, the current backward transconductance amplifier (CBTA) is used, which is one of the most recently reported active elements in the literature. The theoretical results are in detail verified by numerous SPICE simulations using a new low-voltage implementation of CBTA. In the design, the PTM 90nm level-7 CMOS process BSIM3v3 parameters with +/- 0.45V supply voltages were used. The proposed resistorless CBTA-C APF provides easy electronic tuning of the pole frequency in the frequency range from 763 kHz to 17.6 MHz, which is more than one decade. Maximum power dissipation of the circuit is 828 mu W at bias current 233 mu A. Nonideal, parasitic effects, sensitivity analyses, temperature and noise variation, current swing capability, and Monte Carlo analysis results are also provided. Compared to prior state-of-the-art works, the proposed CBTA-C APF has achieved the highest figure of Merit value, which proves its superior performance.