LE79231FQC Zarlink, LE79231FQC Datasheet - Page 3

• Manufacturer Part Number: LE79231FQC
• Description: SLIC 3-CH 63dB 70mA 5V 32-Pin QFN EP
• Manufacturer: Zarlink

Specifications of LE79231FQC

• Package: 32QFN EP
• Number Of Channels Per Chip: 3
• Polarity Reversal: Yes
• Longitudinal Balanced: 63 dB
• Loop Current: 70(Min) mA
• Minimum Operating Supply Voltage: 4.75 V
• Typical Operating Supply Voltage: 5 V
• Typical Supply Current: 26.9 mA

PRODUCT DESCRIPTION
Zarlink’s VoiceEdge family voice chip sets integrate all the functions of the subscriber line. Two chip types are used to
implement the line card
functions:
A complete schematic of the line card using a VoiceEdge chip set for external ringing is shown in the
page
The Le79231 ISLIC device uses reliable, bipolar technology to provide the power necessary to drive a wide variety of subscriber
lines. It can be programmed by the VE790 series ISLAC device to operate in eight different modes that control power
consumption and signaling. This enables it to have full control over the subscriber loop. The Le79231 ISLIC device is designed
to be used exclusively with the VE790 series ISLAC devices. The Le79231 ISLIC device requires only +5 V power and the battery
supplies for its operation.
The Le79231 ISLIC device implements a linear loop-current feeding method with the enhancement of intelligent thermal
management. This limits the amount of power dissipated on the Le79231 ISLIC device by dissipating power in external resistors
in a controlled manner.
Each VE790 series ISLAC device contains high-performance circuits that provide A/D and D/A conversion for the voice (codec),
DC-feed and supervision signals. The VE790 series ISLAC devices contain a DSP core that handles signaling, DC-feed,
supervision and line diagnostics for all channels.
The DSP core selectively interfaces with three types of backplanes:
The 790 series voice chip set provides a complete software configurable solution to the BORSCHT functions as well as complete
programmable control over subscriber line DC-feed characteristics, such as current limit and feed resistance. In addition, these
chip sets provide system level solutions for the loop supervisory functions and metering. In total, they provide a programmable
solution that can satisfy worldwide line card requirements by software configuration.
Software programmed filter coefficients, DC-feed data and supervision data are easily calculated with the WinSLAC software.
This PC software is provided free of charge. It allows the designer to enter a description of system requirements. WinSLAC then
computes the necessary coefficients and plots the predicted system results.
The Le79231 ISLIC device interface unit inside the VE790 series ISLAC devices processes information regarding the line
voltages, loop currents and battery voltage levels. These inputs allow the VE790 series ISLAC devices to place several key
Le79231 ISLIC device performance parameters under software control.
The main functions that can be observed and/or controlled through the VE790 series ISLAC devices backplane interface are:
To accomplish these functions, the Le79231 ISLIC device collects the following information and feeds it, in analog form, to the
Le79Q224x or Le79228 codecs:
The outputs supplied by the VE790 series ISLAC device to the Le79231 ISLIC device are then:
19.
1. The Le79231 ISLIC device: A high voltage, bipolar device that drives the subscriber line, maintains longi-
2. The VE790 series ISLAC devices: Low voltage CMOS ICs that provides conversion, control and DSP func-
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tudinal balance and senses line conditions.
tions for the Le79231 ISLIC device.
Standard PCM/MPI
Standard GCI
Modified GCI with a single analog line per GCI channel
DC-feed characteristics
Ground-key detection
Off-hook detection
Metering signal
Longitudinal operating point
Subscriber line voltage and currents
Ring-trip detection
Abrupt and smooth battery reversal
Subscriber line matching
Ringing
Sophisticated line and circuit tests
The metallic (IMT) and longitudinal (ILG) loop currents
The AC (VTX) and DC (VSAB) loop voltage
A voltage (VHL
—
an Le79231 ISLIC device and a VE790 series ISLAC device. These provide the following basic
i
*) that provides control for the following high-level Le79231 ISLIC device outputs:
Zarlink Semiconductor Inc.
3
Application Circuit, on