ST3938A Datasheet (STMicroelectronics) - SPEECH - TONE/PULSE DIALER

ST3938A, SPEECH - TONE/PULSE DIALER - LED INDICATOR

The device consists of the speech and the dialer functions.

It provides the DC line interface circuit that terminates the telephone line, analog amplifier for speech transmission and necessary signals for either DTMF and pulse dialing.

When mated with a tone ringer, a complete telephonecan be produc

ST3917A ST3917B SPEECH - TONE/PULSE DIALER - LED INDICATOR SPEECH CIRCUIT 2 TO 4 WIRES CONVERSION PRESENT THE PROPER DC PATH FOR THE LINE www.DataSheet4U.com CURRENT AND THE FLEXIBILITY TO ADJUST IT ANDALLOWPARALLEL PHONE OPERATION SYMMETRICAL HIGH IMPEDANCE MICROPHONE INPUTS SUITABLE FOR DYNAMIC, ELECTRET OR PIEZOELECTRIC TRANSDUCER ASYMMETRICAL EARPHONE OUTPUT SUITABLE FOR DYNAMIC TRANSDUCER LINE LOSS COMPENSATION FIXED INTERNALLY BY A.G.C.

INTERNAL MUTING TO DISABLE SPEECH DURING DIALING AND

ST3938A Features

* provided by the PABX or central office. The PAUSE key stores a timed pause in the number sequence. Redial is then delayed until an outside line can be accessed or some other activities occur before normal signalling resumes. A LND key automatically redials the last number dialed. Adedicatedpin MU/MF