The NTE1690 is a monolithic integrated circuit in a 16lead dip Type package fabricated using CMOS process and is designed specifically for integrated Tone dialer applications. Model # NTE1690 Features: High accuracy tones Digital divider logic, resistive ladder network and cmos operational amplifier on a single chip Uses inexpensive 3. 579545MHz television color Burst crystal Invalid Key entry can result in either single Tone or No Tone Tone disable allows any Key D output to function from keyboard input without generating tones.
