Simple PFM demodulator to be used by analogue artificial neural networks which communicate through pulses

A simple PFM demodulator, based on the switched-capacitor technique is presented. The circuit can be used in analogue neural networks where activities are transmitted in the form of frequency-modulated pulse trains with interpulse period reaching milliseconds. The circuit avoids the use of long time constants but displays the capability of demodulating a PFM signal well below the kilohertz frequency range. Measurements on a constructed discrete-component demodulator are presented.