A novel linear square/triangular wave generator with tunable duty cycle

Abstract A novel circuit of square/triangular wave generator consists of single multiple output dual-X current conveyor transconductance amplifier (MO-DXCCTA), one grounded resistor and one grounded capacitor is proposed. One square wave in current mode and one triangular wave in voltage mode are simultaneously available from the proposed generator. The proposed circuit is fully electronically controllable facilitating the feature of duty cycle adjustment. The duty cycle is electronically tunable via bias current. Moreover, a wide sweep of oscillation frequency is possible via grounded capacitor with very good linearity. The tuning of oscillation frequency does not affect the amplitudes of output waveforms. Furthermore, the oscillation frequency can also be controlled electronically and independently via bias current for a fixed duty cycle of 50%. A prototype of MO-DXCCTA using commercial ICs (AD844 and LM13700) is used to carry out the experimental results. Measured results show very good variation of frequency (up to 245.5 kHz) against capacitor with nonlinearity less than 2%.

[1]  Atul Kumar,et al.  Novel electronically controlled current-mode Schmitt trigger based on single active element , 2017 .

[2]  Atul Kumar,et al.  Novel CMOS Dual-X Current Conveyor Transconductance Amplifier Realization with Current-Mode Multifunction Filter and Quadrature Oscillator , 2018, Circuits Syst. Signal Process..

[3]  Hyeong-Woo Cha,et al.  Triangular/square-wave generator with independently controllable frequency and amplitude , 2005, IEEE Transactions on Instrumentation and Measurement.

[4]  Jan Jerabek,et al.  Design of Z-copy controlled-gain voltage differencing current conveyor based adjustable functional generator , 2015, Microelectron. J..

[5]  Giuseppe Ferri,et al.  A CCII‐based non‐inverting Schmitt trigger and its application as astable multivibrator for capacitive sensor interfacing , 2017, Int. J. Circuit Theory Appl..

[6]  Shahram Minaei,et al.  A Simple Schmitt Trigger Circuit with Grounded Passive Elements and Its Application to Square/Triangular Wave Generator , 2012, Circuits Syst. Signal Process..

[7]  Atul Kumar,et al.  Single Active Element-Based Tunable Square/Triangular Wave Generator with Grounded Passive Components , 2017, Circuits Syst. Signal Process..

[8]  Avireni Srinivasulu,et al.  Current Conveyor-Based Square/Triangular Waveform Generators With Improved Linearity , 2009, IEEE Transactions on Instrumentation and Measurement.

[9]  Hoon Kim,et al.  Pulsewidth Modulation Circuits Using CMOS OTAs , 2006, IEEE Transactions on Circuits and Systems I: Regular Papers.

[10]  Jeerasuda Koseeyaporn,et al.  A novel versatile modulator circuit , 2009 .