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NT91214/15 Series
Tone/Pulse Dialer
1
V1.0
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
General Description
The NT91214/15 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 x 4 matrix keyboard can be used to support
either DP or DTMF modes.
Up to 32 digits can be saved in the on-chip RAM for
redialing. In the DTMF mode, a short minimum tone
duration and minimum intertone pause allows rapid
dialing. Maximum tone duration depends on the key
depression time during manual dialing.
Pin Configurations
a. 16-Pin Package
b. 18-Pin Packages
(i) Key Tone Output
c. 20-Pin Package
(ii) Hands-Free Control