AS2578B

The AS2578 /B are a versatile repertory LD/MF diallers with a melody generator, a ring frequency discriminator and a 2-wire interface to EEPROM. Together with the AS2520/1, the AS2578 /B form a coherent basis for a fully electronic telephone with a wide range of options.

The AS2578 /B are especially designed to adapt to different PTT specifications. A RAM is on chip for last number redial, 3 direct dial and 10 numbers with abbreviated dialling. AS2578B allow easy use under a PABX, the device incorporates automatic pause insertion and sliding cursor procedure as selectable options (AS2578) or centrex keys (AS2578B). The device can be used with or without EEPROM as appropriate. When an EEPROM is connected, all RAM content is stored in the EEPROM by power loss.

The circuit of AS2578B provides the possibility to set different modes of operation (LM codes) via the keyboard or via pin options, e.g. default signalling mode, automatic pause insertion, flash or ground loop and settings of volume nd melodies.