HT9172

Supply Voltage .............................V_SS-0.3V to V_SS+6V
Storage Temperature ............................-50 to 125
Input Voltage.............................V_SS-0.3V to V_DD+0.3V
Operating Temperature...........................-40 to 85

Note: These are stress ratings only. Stresses exceeding the range specified under "Absolute Maximum Ratings" may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.

The HT9172 is a Dual Tone Multi Frequency (DTMF) receiver device which includes an integrated digital decoder and band split filter functions as well as power-down and inhibit mode operations. The device uses digital counting techniques to detect and decode the full range of 16 DTMF tone pairs into a 4-bit code output. Highly accurate switched capacitor filters are utilised to divide the DTMF dual tone frequencies into low and high group signals. An integrated dial tone rejection circuit is provided to eliminate the need for pre-filtering.