L3916A Datasheet | SGS Thomson

DESCRIPTION The device consists of the speech and the dialer. It provides the DC line interface circuit that terminates the telephone line, analog amplifier for speech transmission and necessary signals for either DTMF or loop disconnect (pulse) dialing. January 1995 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. 1/15 This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice. - L3926A - L3936A BLOCK DIAGRAM .. DESCRIPTION (continued) When mated with a tone ringer, a plete telephone can be produced with just two ICs. The DC line interface circuit develops its own line voltage across the device and it is adjustable by external resistor to suit different country’s specification. The speech network provides the two to four wires interface, electronic switching between dialing and speech and automatic gain control on transmit and receive. The dialing network buffers up to 32 digits into the LND memory that can be later redialed with a single key input. Additionally, another 13 memories (including 3 emergency memories) of 18 digits memory is available. Users can store all 13 signalling keys and access several unique functions with single key entries. These functions include: Pause/Last Number Dialed (LND), Softswitch, Flash. 2/15 The FLASH key simulates a timed hook flash to transfer calls or to activate other special 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 activity occurs before normal signaling...