Interface / Drivers

Holtek HT9170B / HT9170D DTMF Receiver

The HT9170B/D are Dual Tone Multi Frequency (DTMF) receivers integrated with digital decoder and bandsplit filter functions as well as power-down mode and inhibit mode operations. Such devices use digital counting techniques to detect and decode all the 16 DTMF tone pairs into a 4-bit code output. Highly accurate switched capacitor filters are implemented to divide tone signals into low and high group signals. A built-in dial tone rejection circuit is provided to eliminate the need for pre-filtering.

Features

- Operating voltage: 2.5V~5.5V - Minimal external components - No external filter is required - Low standby current (on power down mode) - Excellent performance - Tristate data output for MCU interface - 3.58MHz crystal or ceramic resonator - 1633Hz can be inhibited by the INH pin - HT9170B: 18-pin DIP package HT9170D: 18-pin SOP package

Holtek HT9200A/HT9200B DTMF Generators

General Description The HT9200A/B tone generators are designed for MCU interfaces. They can be instructed by a MCU to generate 16 dual tones and 8 single tones from the DTMF pin. The HT9200A provides a serial mode whereas the HT9200B contains a selectable serial/parallel mode interface for various applications such as security systems, home automation, remote control through telephone lines, communication systems, etc.

Features

Features · Operating voltage: 2.5V~5.5V · Serial mode for the HT9200A · Serial/parallel mode for the HT9200B · Low standby current · Low total harmonic distortion · 3.58MHz crystal or ceramic resonator · HT9200A: 8-pin SOP package - HT9200B: 14-pin SOP package