TP5089

TP5089 DTMF(TOUCH-TONE) Generator December 1991 TP5089 DTMF (TOUCH-TONE) Generator General Description The TP5089 is a low threshold voltage field-implanted metal gate CMOS integrated circuit It interfaces directly to a standard telephone keypad and generates all dual tone multi-frequency pairs required in tone-dialing systems The tone synthesizers are locked to an on-chip reference oscillator using an inexpensive 3 579545 MHz crystal for high tone accuracy The crystal and an output load resistor are the only external components required for tone generation A MUTE OUT logic signal which changes state when any key is depressed is also provided Features Y Y Y Y Y Y Y Y Y 3 5V – 10V operation when generating tones 2V operation of keyscan and MUTE logic Static sensing of key closures or logic inputs On-chip 3 579545 MHz crystal-controlled oscillator Output amplitudes proportional to supply voltage High group pre-emphasis Low harmonic distortion Open emitter-follower low-impedance output SINGLE TONE INHIBIT pin Block Diagram TL H 5057 – 1 FIGURE 1 C1995 National Semiconductor Corporation TL H 5057 RRD-B30M115 Printed in U S A Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage (VDD b VSS) Maximum Voltage at Any Pin 15V VDD a 0 3V to VSS b 0 3V Operating Temperature Storage Temperature Maximum Power Dissipation b 30 C to a 60 C ...