EM91420A

TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE AND DUAL-TONE MELODY GENERATOR AND DUAL-TONE MELODY GENERATOR EM91420 SERIES EM91420 SERIES GENERAL DESCRIPTION The EM91420 is a series of tone/pulse switchable dialers that is composed of T/P dialer and T/P dialer with 20-set memories. The EM91420 series provides necessary functions of telephone set for application in any environment, such as Pulse dialing, Tone (DTMF) dialing, Handfree dialing, keying tone ,and lock functions. The lock function is designed to inhibit toll dialing operation. Beside this, melody generator, ring detector and SDO (Serial Data Output) functions are provided in advance version. Melody generator will output dual-tone music in line hold duration. Ring detector can prevent illegal dialing from pocket dialer. The SDO is designed to drive LCD driver and voice synthesizer. In this application, the dialing numbers can be displayed on LCD screen with EM32100 ( or EM32116 ). FEATURES Tone/Pulse switchable. Wide operating voltage from 2.0 V to 5.5 V. Low operating current, 0.15 mA (Pulse) and 0.3 mA (Tone) typically. Adding resistor on keyboard scan pin that can select many telephone specifications, such as : Pulse rate, M/B ratio, Flash time, lock dialing functions. SDO function supports LCD driver and voice synthesizer to indicate dialing numbers. Line hold function is designed for stopping conversation temporality. Melody generator provides m...