A new CMOS astable multivibrator and its nonlinear analysis

Abstract

SUMMARYWe present a nonlinear analysis of a new inductively tuned astable multivibrator obtained by connecting a timing inductor across a composite nonlinear resistor with a characteristic of N -type, which is made up of the parallel connection of two complementary pairs of cross-coupled MOS devices. Some possible practical applications of the circuit are also envisaged. Closed-form expressions for the amplitude and the period of the periodic oscillation are derived in both cases when the circuit exhibits a relaxation oscillation and in the more difficult case when, due to the effect of parasitic capacitances of the devices, the circuit has an almost-discontinuous relaxation oscillation with a nonzero switching time. The accuracy of the presented formulas, which are useful for both the analysis and design, is validated through circuit simulations and experimental results.

A CCII‐based non‐inverting Schmitt trigger and its application as astable multivibrator for capacitive sensor interfacing

“…In this sense, oscillators are typically employed as capacitive sensor interfaces because when a capacitance variation occurs, the circuit can be set in order to show linear and wide output waveform period variations. Furthermore, they can still be employed as resistive sensor interfaces even if, in some cases, the output waveform period is not linearly proportional to the sensing element (typically due to the presence of a logarithmic term) .…”

“…Oscillators are typically based on voltage comparators and positive feedbacks. In the literature, several solutions about CM Schmitt trigger circuits, working as analogue comparators, have been proposed , mainly employing custom solutions that are particularly aimed to use a reduced number of components, to be employed in LV and LP applications and to develop novel techniques towards the threshold setting capability.…”