Comments on “Design and modeling of an intelligent temperature to frequency converter”

In a recent work, Kumar et al. have presented design and modeling of an intelligent temperature to frequency converter (TFC) for thermistor in the input temperature range of 0-100 °C [1]. In this work, a 555-timer based a signal conditioning circuit (SCC) was employed as TFC. Linearity, between the input temperature and the output frequency, was further enhanced with the application of artificial neural network. It is pointed out that this work developed erroneous frequency expression, waveforms and SCC circuit. In this comment, based on detailed mathematical formulations supported by Multisim™ simulation results, errors of the reported intelligent TFC are pointed out and the required corrections are proposed.