AS2540 Description
The AS2540 is a CMOS integrated circuit that incorporates a speech circuit (line-adaptation, 2/4-wire conversion, separate Rx- and Tx-amplifiers for handset and modem), MF dialler, ring frequency detector, ring melody generator and a two wire serial interface. It shall act as an a/b-line-powered device in order to interface a main-powered CPU to the analogue telephone line. AS2540 can operate in a so-called...
AS2540 Key Features
- Line Interface, Speech Circuit, MF Dialler and Tone Ringer on a 28 pin CMOS chip
- Programmable via 2-wire serial interface (UART 9600 baud, 8N1)
- Watch dog timer for Backup Mode
- Additional input for modem transmit path
- Additional output for modem receive path
- CMOS for high EMC immunity
- Low Noise (max. -72 dBm)
- Soft clipping for handset operation to avoid harsh distortion
- Line loss pensation selectable by pin option
- Real and plex impedance selectable by external