le79231 Zarlink Semiconductor, le79231 Datasheet - Page 6

• Manufacturer Part Number: le79231
• Description: Intelligent Subscriber Line Interface Circuit
• Manufacturer: Zarlink Semiconductor

FEATURES OF THE VE790 SERIES CHIP SET
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Performs all battery feed, overvoltage, ring-trip, signal-
ing, coding, hybrid and test (BORSCHT) functions
Two chip solution supports high density, multi-channel
architecture
Single hardware design meets multiple country require-
ments through software programming of:
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Supports external battery-backed ringing
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Supports metering generation with envelope shaping
Smooth or abrupt polarity reversal
Adaptive transhybrid balance
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Supports both loop-start and ground-start signaling
DC loop-feed characteristics and current-limit
Loop-supervision detection thresholds
– Off-hook debounce circuit
– Ground-key and ring-trip filters
Off-hook detect de-bounce interval
Two-wire AC impedance
Transhybrid balance
Transmit and receive gains
Equalization
Digital I/O pins
A-law/µ-law and linear selection
Unbalanced ringing
Ring relay driver
Ring relay operation synchronized to zero crossings
of ringing voltage and current
Integrated ring-trip filter and software enabled man-
ual or automatic ring-trip mode
Continuous or adapt and freeze
Zarlink Semiconductor Inc.
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— Echo gain, distortion, and noise
Exceeds LSSGR and CCITT central office requirements
Selectable PCM or GCI interface
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On-hook transmission
Power/service denial mode
Line-feed characteristics independent of battery voltage
Only 5 V, 3.3 V and battery supplies needed
Low idle-power per line
Linear power-feed with intelligent power-management
feature
Compatible with inexpensive protection networks;
Accommodates low-tolerance fuse resistors while main-
taining longitudinal balance
Monitors two-wire interface voltages and currents for
subscriber line diagnostics
Built-in voice-path test modes
Power-cross, fault, and foreign voltage detection
Integrated line-test features
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Integrated self-test features
Guaranteed performance over commercial and industrial
temperature ranges.
Up to three relay drivers per Le79231 ISLIC device
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Supports most available master clock frequencies
from 512 kHz to 8.192 MHz
Leakage
Line and ringer capacitance
Loop resistance
Configurable as test load switches