A new adjustable square/triangular-wave generator using CCII/CCCII and OTA

Abstract

A study on two new circuits to generate square/triangular waveforms are presented. Circuit-I consists of a CCII, a capacitor, an OTA and a voltage divider network. The frequency can be changed by changing the voltage division ratio or the time-constant and amplitude by a combination thereof. As an extension of this concept, in the proposed circuit-II a CCCII is used in place of CCII to get electronic control through a bias current. Again, the frequency of the waveform can be adjusted by the bias current of the CCCII or the voltage division ratio and amplitude by a combination thereof. The circuits have been fully analyzed to deduce both ideal as well as non-ideal design equations. Proposed circuits have been extensively studied using the LTspice circuit simulator and one of them is experimentally verified with components available in our lab. The measured waveforms perfectly match with the theoretical/simulated waveforms. Finally, a comparison with the recently proposed works is also included.