TP5089 Datasheet, PDF (1/6 Pages) National Semiconductor (TI) – TP5089 DTMF (TOUCH-TONE) Generator

December 1991
TP5089 DTMF (TOUCH-TONE) Generator
General Description
The TP5089 is a low threshold voltage field-implanted met-
al gate CMOS integrated circuit It interfaces directly to a
standard telephone keypad and generates all dual tone mul-
ti-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 _{3 5V – 10V operation when generating tones}
Y _{2V operation of keyscan and MUTE logic}
Y _{Static sensing of key closures or logic inputs}
Y _{On-chip 3 579545 MHz crystal-controlled oscillator}
Y _{Output amplitudes proportional to supply voltage}
Y _{High group pre-emphasis}
Y _{Low harmonic distortion}
Y _{Open emitter-follower low-impedance output}
Y _{SINGLE TONE INHIBIT pin}
Block Diagram
FIGURE 1
C1995 National Semiconductor Corporation TL H 5057
TL H 5057 – 1
RRD-B30M115 Printed in U S A