DESCRIPTION
The  SC91214/15  Series  is  a  single-chip,  silicon  gate,  CMOS integrated  circuit  with  an  on-chip  oscillator  for  a  3.58MHZ  crystal  or ceramic  resonator.  It  provides  a  dialing  pulse  (DP)  or  dual  tone  multi-frequency (DTMF) dialing. A standard 4 X4 matrix keyboard can be used to support either DP or DTMF modes.

FEATURES
* One touch redial operation
* Tone/Pulse switchable
* 32 digit capacity for redialing
* Automatic mixed redialing (last number redial) of pulse to DTMF with multiple automatic access pauses
* PABX auto-pause is 2.2 seconds
* DTMF Timing:
   Manual dialing: minimum duration for bursts and pauses Redialing: calibrated timing
* Hands-Free control function
* Wide operating voltage range: 2V to 5.5V
* Key-in beep tone output
* Digits dialed manually after redialing are cascadable and stored as additional digits for the next redialing
* Uses inexpensive ceramic resonator (3.58 MHZ)
* Two versions for different telephone systems
* Built-in power up reset circuit
* Four extra function keys: flash, pause, redial and DP or DTMF mixed dialing
* 4 X 4 (or 2 X 8) keyboard can be used
* Low standby current