GENERAL DESCRIPTION
The EM91810A/B are Tone/Pulse switchable dialer which are fabricated in CMOS technology with wide operating voltage for both tone and pulse mode, and consumes very low memory retention current in ON-HOOK state. EM91810A/B also provide SDO (serial data output) function to drive LCD driver (EM32100, EM32116, EM32117) and voice synthesizer.

FEATURES
• Tone/pulse switchable dialer.
• One 32-digit last number redial memory.
• Pulse to tone (P→T) is provided for PBX operation.
• Flash key is available.
• Minimum tone duration is 98ms or 83ms.
• Minimum intertone pause is 98ms or 83ms.
• Uses 3.579545 MHz crystal or ceramic resonator.
• Many options can be selected.
    Mode (10 PPS ; 20 PPS ; Tone)
    M/B ratio (40 : 60 ; 33 : 66)
    Pause time (3.6s)
• Flash function (RESET)
    P→T pause time (3.6s)
    Flash time (600ms; 300ms; 100ms; or 80ms).
• Mixed dialing.
• Handfree function is provided for speaker phone application.
• Power on reset circuit is provided.
• Package in DIP18 or DIP20.
• SDO function that is supported to drive LCD driver (EM32100) and voice synthesizer to indicate dialing number.
• Key tone function is provided.