The HEF4519B provides four multiplexing circuits with common select inputs (SA, SB); each circuit contains two inputs (An, Bn) and one output (On). It may be used to select four bits of information from one of two sources. The HEF4519B cannot be used to multiplex analogue signals. The outputs utilize standard buffers for best performance.
The IN91531N provides a 4-bit data input and a handshaking signal to serve as microcomputer interfaces. Under microcomputer control the IN91531N generates both a DTMF signal and a pulse output for telephone dialing. All necessary dual -tone frequencies and dial pulse outputs are derived from the widely used TV crystal standard, providing high accuracy and stability. The required sinusoidal waveform for individual tones is digitally synthesized on the chip, resulting in a waveform with very low total harmonic distortion.
1. TTL compatible inputs and outputs
2. Uses TV crystal standard (3.58 MHz) to derive all frequencies, providing high accuracy and stability
3. Operating voltage: 2.5 to 5.5 Volts
4. Selectable M/B ratio
5. 10 PPS dial rate
6. High group tone pre-emphasis : 2 dB
7. Low total harmonic distortion in DTMF signaling
Other data sheets within the file : 91531, IL91531N