Measurements and Analytical Computer-Based Study of CMOS Inverters and Schmitt Triggers

Umesh Kumar

doi:10.1155/1996/52421

Abstract

Modified CMOS inverters with three and four transistors have been made. Two varieties of CMOS Schmitt Triggers have been considered. CMOS Schmitt Trigger with wide hysteresis has been obtained. Complete detailed theoretical, experimental and computer based results are derived and exhibited.

Highlights

CMOS circuits have revolutionized the digital applications
A large range of threshold voltage change and very low loading of the control signal source makes it possible for such a mode of threshold voltage regulation to have an advantage over the conventional voltage control through power supply variations
A Schmitt Trigger consisting of only four MOS transistors has been obtained

Summary

INTRODUCTION

CMOS circuits have revolutionized the digital applications. In this paper, the behavior of CMOS transistors used in inverters and Schmitt Triggers have been analysed. The Schmitt Trigger circuit using four transistors is analyzed in view of voltage controlled and resistance controlled thresholds and the characteristics for various voltage relationships are obtained. The controlling voltage Vx has influence on the transfer characteristics shape. With reference to the standard inverter the slope of the transfer characteristics in the transient range is increased as in the linearity range, being of special importance in analog applications of inverters In this case, one more pair of CMOS transistors has been added to the basis inverter (Fig. 4). Assuming that the input voltage is varied from a zero value to the supply voltage level (VDo), the transfer characteristics, with reference to the states of individual transistors, can be divided into seven different regions shown in (Fig. 6a,b).

Vrn V’Tn

Findings

CONCLUSION