austriamicrosystems
Multi-Standard CMOS Telephone IC
for Basic Telephones
AS2533-36
DATA SHEET
General Description
The AS253x is a CMOS integrated circuit that contains all
the functions needed to build a high performance electronic
telephone set with basic features.
The AS253x incorporates a line interface, a speech circuit,
a dialler and ringer. It is a real single-chip / single-die IC
with 28 pins. It allows either package mounting or chip-on-
board mounting.
The device is available in 4 versions (pin-compatible) with
different features ranging from LNR only (last number
redial) to 4 direct (one-touch) memories and 10 indirect
(two-touch) memories. The sliding cursor procedure makes
the LNR function easy to use under various PABX systems.
The versatility of the circuit is provided by pin options and a
few external components. This allows fast time-to-market
and easy adaptation to different PTT requirements. A
unique EMI performance has been achieved due to the
consequent use of CMOS amplifiers.
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Rx and Tx soft clipping to avoid harsh distortion
Real or complex impedance (EU compliant)
Stabilized supply for dialler and peripherals
Automatic line loss compensation
Operating range from 13 to 100 mA (down to 5 mA with
reduced performance)
Unique EMI performance (EU compliant)
Dialler
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LD/MF dialing and mixed-mode dialing
31 digit last number redial (LNR)
4 direct/10 indirect (AS2533/36), 12 direct (AS2535)
Repeat dialing by busy or engaged (not AS2535)
Confidence tone during memory programming and mute
Notepad memory function
Pause key for access pause or wait function
3 flash timings, 100 ms, 280 ms and 375/600 ms
Sliding cursor protocol with comparison
Ringer
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Key Features
Line Interface and Speech Circuit
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Electronic Rx volume control
Electronic microphone mute
Microphone amplifier with symmetrical input
Ring frequency discrimination
3-tone melody generator
Ring melody selection via keyboard
Ring volume selection via keyboard
Version available with fixed ring melody and ring volume
Package
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SOIC 28 or DIE
Block Diagram
Figure 1 Block Diagram
Revision 8.8
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AMSCO [ AUSTRIAMICROSYSTEMS AG ]
