Using the 73M2901CE DTMF Detector


One of the features of the Teridian 73M2901CE single-chip V.22bis modem is the dual tone multiple frequency (DTMF) detection function. The DTMF detector uses Goertzel filters to detect valid DTMF tone pairs, which is a discrete Fourier transform (DFT) technique commonly used for detecting specific frequencies. The 73M2901CE supports all the modes described in this application note.