™
Le77D11
Voice Over Subscriber Line Interface Circuit
VE770 Series
APPLICATIONS
Short/Medium Loop: approximately 2000 ft. of 26 AWG,
and 5 REN loads
Voice over IP/DSL – Integrated Access Devices, Smart
Residential Gateways, Home Gateway/Router
Cable Telephony – NIU, Set-Top Box, Home Side Box,
Cable Modem, Cable PC
Fiber–Fiber In The Loop (FITL), Fiber to the Home
(FTTH)
Wireless Local Loop, Intelligent PBX, ISDN NT1/TA
ORDERING INFORMATION
An Le78D11 VoSLAC™ device must be used with this part.
Device
Le77D112TC
Le77D112BTC
44-pin eTQFP
44-pin eTQFP (Green package)*
Package
*Green package meets RoHS Directive 2002/95/EC of the European
Council to minimize the environmental impact of electrical equipment.
DESCRIPTION
The
Zarlink
Le77D11 dual-channel Voice over Subscriber
Line Interface Circuit (VoSLIC™) device has enhanced and
optimized features to directly address the requirements of
voice over broadband applications. Their common goal is to
reduce system level costs, space, and power through higher
levels of integration, and to reduce the total cost of ownership
by offering better quality of service. The Le78D11/Le77D11 is a
two-device chip set providing a totally software configurable
solution to the BORSCHT functions for two lines. The resulting
system is less complex, smaller, and denser, yet cost effective
with minimal external components. The Le77D11 Dual VoSLIC
device requires only two power supplies: +3.3 VDC and
nominally +12 VDC, but can range from +8 to +40 VDC
depending on the application. A single TTL-level clock source
drives the two switching regulators that generate the required
line voltage dynamically on a “per line” basis. Six
programmable states are available: Low Power Standby,
Disconnect, Normal Active, Reverse Polarity, Ringing and Line
Test. Binary fault detection is provided upon application of fault
conditions or thermal overload.
FEATURES
Integrated Dual-Channel Chip set
— Built-in boost switching power supply tracks line voltage
minimizing power dissipation
— Only +3.3 V and +12 V (nominal) required
— Wide range of input voltages (+8 V to +40 V) supported
— Minimum external discrete components
— 44-pin eTQFP package
Ringing
— 5REN
— Up to 90 Vpk, Balanced
— Sinusoidal or trapezoidal with programmable DC offset
Subscriber Loop Test/Self-Test
— GR-909 compliant drop test capability in both
measurements and pass/fail
– Hazardous Potential
– Foreign Electromotive Force
– Resistive Faults
– Receive Off-hook
– Ringers Test
– Loop Length
World Wide Programmability:
— Two-wire AC impedance
— Dual Current Limit
— Metering
— Programmable loop closure and ring trip thresholds
Six SLIC Device States, including:
— Low power Standby state
— On-hook transmission
— Reverse Polarity
BLOCK DIAGRAM
Le77D11 SLIC
Switching Power
Supply
2-wire
Tip+Ring
Interface
Ring
Tip
2-wire to 4-wire
conversion
Le78D11
Codec
Codec
Interface
2-wire to 4-wire
conversion
2-wire
Tip+Ring
Interface
Switching Power
Supply
RELATED LITERATURE
080697 Le78D11 Data Sheet
080716 Le77D11/Le78D11 Chip Set User’s Guide
081013 Layout Considerations for the Le77D11 and
Le9502 Application Note
Ring
Tip
Document ID#
080696
Date:
Rev:
G
Version:
Distribution:
Public Document
Sep 19, 2007
2
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
