Dual Intelligent Subscriber Line Audio-Processing Circuit
Intelligent Access™ Voice Solutions
www.DataSheet4U.com
Am79D2251
Dual Intelligent Subscriber Line Audio-Processing Cir...
Description
Intelligent Access™ Voice Solutions
www.DataSheet4U.com
Am79D2251
Dual Intelligent Subscriber Line Audio-Processing Circuit (ISLAC)
DISTINCTIVE CHARACTERISTICS
s High performance digital signal processor provides programmable control of all major linecard functions — 32 and 24 kb/s ADPCM to G726, as well as A-law/µ-law and linear codec — Transmit and receive gain — Two-wire AC impedance — Transhybrid balance — Equalization — DC loop feeding — Smooth or abrupt polarity reversal — Loop supervision — Off-hook debounce circuit — Ground-key and ring-trip filters — Ringing generation and control — Adaptive hybrid balance — Line and circuit testing — Tone generation — Metering generation at 12 kHz and 16 kHz — Envelope shaping and level control s Selectable PCM/MPI or GCI digital interfaces — Supports most available master clock frequencies from 512 kHz to 8.196 MHz s 0 to 70°C commercial operation — –40°C to 85°C extended temperature range available s +3.3 V DC operation s Exceeds LSSGR and ITU requirements s Supports external ringing with on-chip ring-trip circuit — Automatic or manual ring-trip modes s DTMF detection according to Q.24 s 2100 Hz modem tone detection according to V.25
BLOCK DIAGRAM
A1
ISLIC
7 4 LD1 VREF
VCCA VCCD DGND1
B1 RC Networks and Protection A2
7 3 AGND1
DGND2
AGND2
TSCA/G
P1-P3
ISLIC
LD2
DRA/DD DXA/DU DCLK/S0 PCLK/FS
B2
RREF
Dual ISLAC
5
Ring-Trip Sense Resistors
5
MCLK
RSHB
BATH
RSLB
FS/DCL CS/RST DIO/S1
BATL
RSPB
BATP
INT
Pub. # 22829...
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