Preliminary Data Sheet
AS2507
®
Austria Mikro Systeme International AG
Single Chip 2-Wire Intercom
CMOS Integrated Circuit
General Description
The AS2507 is a CMOS integrated circuit that
contains all the functions needed to build a 2-
wire intercom network.
The device incorporates 2/4-wire conversion
(hybrid), soft clipping for high speech quality,
FSK modem and a simple interface to a
microcontroller.
The signalling mode is selectable between
FSK modulation and burst mode.
The low standby current (typ. 2 mA) allows
several devices to listen to the 2-wire line.
The speech circuit is designed for compatibility
with commonly used handset (150Ω earpiece
and electret microphone) with receive gain of
-6 dB and transmit gain of 32 dB (relative to
line).
Key Features
Line/speech circuit and signalling on one 14
pin CMOS chip
Only 2 wires needed for power supply,
signalling and speech
Soft clipping to avoid harsh distortion
Fully integrated 2/4 wire conversion
Side tone cancellation
Low noise
Signalling with FSK modem
Low standby power consumption allows
parallel operation of up to 25 terminals on a
bus pair with central supply
Parallel operation of up to 70 terminals if
supplied locally
Controllable via simple µC interface
Very few external components
Application
Entrance telephone system, intercom and data
transmission, alarm systems, toy phone
Package
Available in 14 pin DIP and 16 pin SOIC
Block Diagram
1/9
July 1998
AMSCO [ AUSTRIAMICROSYSTEMS AG ]
