Dual-Tone Multiple Frequency

Dual-Tone Multiple Frequency (DTMF) transmitters incorporate a multi-functional tone generator which supports:

  • DTMF dialing (the tone you hear when you press a number on a touch tone telephone)

  • Melody-on-hold (generate a simple melody when you are on hold)

  • Pacifier tone functions (acknowledge button pressed)

Dual-Tone Multiple Frequency (DTMF) receivers can detect and qualify DTMF signals. The 68HC05F5 DTMF utilizes a switched capacitor technology for filtering. Included is a Pre-emphasis filter (for high frequency gain) and two band separation filters (for high and low frequencies). There are an additional eight bandpass filters for final frequency selection.