Simple Current-Controlled VDTA-R Schmitt Trigger Circuit

A simple current-controlled Schmitt trigger circuit employing single voltage differencing transconductance amplifier (VDTA) and only two grounded resistors is presented. The proposed Schmitt trigger circuit offers independent electronic adjustability of its threshold voltage levels and output voltage amplitudes by the help of corresponding VDTA bias currents. In addition, both clockwise and counter-clockwise hystereses are also achievable. To justify the theoretical predictions, the verification of the proposed Schmitt trigger circuit is performed by PSPICE simulation software using TSMC $0.25-\mu\mathbf{m}$ CMOS technology.