LE79Q2281DVC

Telecom Overview

The LE79Q2281DVC is a Quad Intelligent Subscriber Line Audio-processing Circuit (ISLAC) from the VE790 Series, manufactured by Microchip Technology. It operates on a +3.3 V DC supply and is housed in a 64-pin TQFP package. The device integrates a high-performance digital signal processor to manage four subscriber line channels, providing programmable control over BORSCHT functions including A-law/µ-law codec/filtering, transmit/receive gain, two-wire AC impedance, transhybrid balance, equalization, DC loop feeding, polarity reversal, and loop supervision. It supports selectable PCM/MPI or GCI digital interfaces with master clock frequencies ranging from 512 kHz to 8.192 MHz.

Telecom Feature Summary

• Integrates a high-performance DSP for programmable control of all major line card functions, including codec/filtering, hybrid balance, and loop supervision.
• Supports selectable PCM/MPI or GCI digital interfaces compatible with various master clock frequencies.
• Provides integrated self-test and line-test capabilities to resolve faults to the line or line circuit without dedicated external hardware.
• Includes general-purpose I/O pins and supports both internal and external ringing generation with ring-trip detection.

Telecom Applications

• Voice over IP/DSL Integrated Access Devices (IAD), Smart Residential Gateways (SRG), Home Gateway/Router
• Cable Telephony Network Interface Units (NIU), Set-Top Box, Home Side Box, Cable Modem, Cable PC
• Fiber in the Loop (FITL), Fiber to the Home (FTTH)
• Wireless Local Loop, Intelligent PBX, DLC-MUX, Central Office (CO)

Telecom Procurement Notes

Verify the specific ordering suffix 'DVC' corresponds to the 64-pin TQFP tray packaging as documented in the official datasheet. Confirm that the component meets RoHS Directive 2002/95/EC requirements if environmental compliance is necessary for the application. Ensure compatibility with the required digital interface mode (PCM or GCI) during the design phase.

Telecom Selection Notes

Select this component when designing a low-cost, high-performance, fully software-programmable line interface for multiple country applications. It is suitable for designs requiring integrated test capabilities where dedicated test hardware is not cost-effective. Consider the 64-pin TQFP package constraints and ensure the system architecture supports the VE790 series ISLIC companion devices for complete line interface implementation.

Telecom Part Context

The LE79Q2281DVC belongs to the Le79228 Quad ISLAC family within the VE790 Series voice chip sets. Originally developed by Zarlink Semiconductor, the product technology was acquired by Legerity Holdings and subsequently by Microchip Technology. This device works in conjunction with VE790 series ISLIC devices to implement a universal telephone line interface for four subscriber lines.

Telecom Replacement Considerations

The LE79Q2284MVC is an alternative part number within the same family, offering identical functionality but packaged in an 80-pin LQFP format instead of the 64-pin TQFP used by the LE79Q2281DVC. Designers must account for pinout differences and board layout changes when substituting between these package types.

Telecom FAQ

What digital interfaces does the LE79Q2281DVC support?

The device supports selectable PCM/MPI or GCI digital interfaces. For PCM operation, it accepts master clock frequencies from 512 kHz to 8.192 MHz.

How does the LE79Q2281DVC handle line testing?

It provides integrated self-test and line-test capabilities, allowing designers to resolve faults to the line or line circuit. This includes measuring leakage, line and ringer capacitance, and loop resistance, which is crucial for remote applications.

Can the LE79Q2281DVC generate ringing signals internally?

Yes, the device features internal ringing generation and integrated ring-trip detection. It also supports external ringing with on-chip ring-trip circuits in either automatic or manual modes.