Description

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 General Description 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.