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.

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 music on hold function.
• Lock function provides conventionality key lock and password lock operations.
• Ring detector is designed to prevent illegal dialing from pocket dialer.
• 20-set three touch repertory memory, each one can hold data up to 16 digits.
• A 32-digit LNB (last number) redial memory.
• Keytone function provides rapidly keying recognition.
• Handfree function provides on-hook dialing and speakerphone application.
• Pause and P-T time are fixed to 3.6 seconds.
• Tone duration and inter-tone pause time are fixed to 98 ms.
• Using 3.579545 MHz crystal or ceramic resonator.
• Package forms: PDIP, skinny.