Electronically tunable current-mode square-root-domain first-order multifunction filter

Abstract

In this article, a new current-mode square-root-domain first-order multifunction filter is designed. The filter circuit has a very simple structure; it uses only the Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) and a grounded capacitor. All transistors’ aspect ratios are the same. It provides lowpass, highpass and allpass responses simultaneously for a single input signal. It can be electronically tuned by changing an external DC current. The filter operates with a single supply voltage of 2.5 V. The proposed circuit has been simulated with PSPICE electronics circuit simulation program (Cadence OrCAD Capture CIS Version 9.2) simulation programs using TSMC 0.35 μm (Taiwan Semiconductor Manufacturing Company) Complementary Metal-Oxide-Semiconductor (CMOS) process parameters.