L3914A Datasheet, PDF (1/15 Pages) STMicroelectronics – SPEECH AND 14 MEMORY DIALER WITH HOLD FUNCTION

L3914A
L3924A - L3934A
SPEECH AND 14 MEMORY DIALER WITH HOLD FUNCTION
ADVANCE DATA
SPEECH CIRCUIT
2 TO 4 WIRES CONVERSION
PRESENT THE PROPER DC PATH FOR THE
LINE CURRENT AND THE FLEXIBILITY TO
ADJUST IT AND ALLOW PARALLEL PHONE
OPERATION
PROVIDES SUPPLY WITH LIMITED CUR-
RENT FOR EXTERNAL CIRCUITRY
SYMMETRICAL HIGH IMPEDANCE MICRO-
PHONE INPUTS SUITABLE FOR DYNAMIC
ELECTRET
OR
PIEZOELECTRIC
TRANSDUCER
ASYMMETRICAL EARPHONE OUTPUT
SUITABLE FOR DYNAMIC TRANSDUCER
LINE LOSS COMPENSATION
INTERNAL MUTING TO DISABLE SPEECH
DURING DIALING
HOLD FUNCTION FOR PARALLEL PHONE
WITH 400ms DELAY TO PREVENT FALSE
RELEASE
DIALER CIRCUIT
32 DIGITS FOR LAST NUMBER REDIAL
BUFFER
18 DIGITS FOR 13 MEMORY REDIAL
ALLOW MIXED MODE DIALING IN EITHER
TONE OR PULSE MODE
PACIFIER TONE PROVIDES AUDIBLE INDI-
CATION OF VALID KEY PRESSED IN A
BUZZER OR/AND IN THE EARPHONE
TIMED PABX PAUSE
FLASH INITIATES TIMED BREAK:
MASK OPTIONS WITH 585ms,300ms,100ms
CONTINUOUS TONE FOR EACH DIGIT UN-
TIL KEY RELEASE
USES INEXPENSIVE 3.579545MHz CE-
RAMIC RESONATOR
POWERED FROM TELEPHONE LINE, LOW
OPERATING VOLTAGE FOR LONG LOOP
APPLICATION
DIP28
SO28
ORDERING NUMBERS:
L3914AN
L3914AD
L3924AN
L3924AD
L3934AN
L3934AD
PIN CONNECTION (Top view)
KEYPAD CONFIGURATION
DESCRIPTION
The device consists of the speech and the dialer.
It provides the DC line interface circuit that termi-
nates the telephone line, analog amplifier for
speech transmission and necessary signals for
either DTMF or loop disconnect (pulse) dialing.
Note: PAUSE/LND:
PAUSE and LND functions are sharing the same key with different
sequence. Hereafter, PAUSE and LND keys arereferring to the same
key.
January 1995
1/15
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.