Decodificador Dtmf Ht9170 Dip18 Itytarg

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 C 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 HT9170 series are Dual Tone Multi Frequency (DTMF) receivers integrated with digital decoder and bandsplit filter functions. The
HT9170B and HT9170D types supply
power-down mode and inhibit mode operations.
All types of the HT9170 series 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
employed to divide tone (DTMF) signals into
low and high group signals. A built-in dial tone
rejection circuit is provided to eliminate the
need for pre-filtering.

Introduction The HT9170 is a Dual Tone Multi Frequency (DTMF) receiver integrating a digital decoder and bandsplit filter functions. The HT9170B and HT9170D devices can enter the power down mode. The HT9170 series all use the digital counting techniques to detect and decode the 16 kinds of DTMF input into a 4-bit code output. Highly accurate filter circuits are implemented to divide tone signals into high frequency and low frequency signal.

The HT9170 series consist of three bandpass filters and two digital decoder circuits to convert a tone DTMF signal into some signal output. It has a built-in amplifier circuit to adjust the input signal. The pre-filter circuit may filter out the dialing tone of 350Hz to 400Hz signal, and then use the high-pass and low-pass filters to split into high and low frequency signals. How to Use the HT9170 DTMF Receiver 2 When the HT9170 receives an effective tone (DTMF) signal, the DV pin goes high and the tone code (DTMF) signal is transferred to its internal circuitry for decoding. After setting, the OE pin goes high, the DTMF decoder will appear on pins D0~D3.