Description
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.
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/MFI is used to select the muting for transmit amplifier and lighted dial LED for keyboard illumination or a LEDindicator for tonemode indication. The SEL pin allows selection of any one of the four poss.
ST3938B Datasheet
