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Microchip Technology LE79Q2281DVC
- Part No.:
- LE79Q2281DVC
- Manufacturer:
- Microchip Technology
- Category:
- Telecom
- Package:
- 64-TQFP
- Datasheet:
-
LE79Q2281DVC.pdf
- Description:
- IC TELECOM INTERFACE 64TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,234
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Product details
Overview
LE79Q2281DVC from Zarlink Semiconductor is a quad-channel intelligent subscriber line audio-processing circuit (ISLAC™) designed for BORSCHT implementation in voice-over-broadband line cards. It delivers programmable A-law/µ-law/linear codec, transhybrid balance, DC loop feeding, ring-trip detection, and tone generation (DTMF/FSK/metering) across four channels, operating at +3.3 V with 64-pin TQFP packaging for VoIP IADs and cable telephony NIUs.
For engineers reviewing the LE79Q2281DVC datasheet, LE79Q2281DVC pinout, LE79Q2281DVC application, or LE79Q2281DVC equivalent, this device serves as the DSP and interface controller in dual-chip ISLAC+ISLIC voice line card architectures-requiring precise coordination of PCM/GCI timing, VE790-series SLIC control signals (LD1–LD4, P1–P3), analog sense inputs (VILG/VIMT), and ringing generation parameters.
Technical Context
The LE79Q2281DVC implements a four-channel digital signal processor core that manages full BORSCHT functions-including programmable transmit/receive gain, two-wire AC impedance, equalization, and adaptive hybrid balance-via software-configurable filter coefficients calculated using WinSLAC™. It interfaces exclusively with VE790-series ISLIC devices to control high-voltage line driving functions.
It supports dual digital backplane modes: selectable PCM/MPI (with 512 kHz–8.192 MHz master clock support) or GCI, with 5-V tolerant I/O pins (CS/RST, DCLK/S0, FS/DCL, PCLK/FS). Its analog front-end includes four independent A/D and D/A converters, reference current generation via IREF, and dedicated sense inputs (VILG/VIMT/VSAB/VHL) per channel for real-time loop monitoring and diagnostics.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Channels | 4 independent subscriber line processing paths with shared DSP core and separate analog I/O |
| Supply Voltage | +3.3 V DC for both analog (VCCA1–VCCA4) and digital (VCCD) sections; no 5 V supply required |
| Digital Interface | Selectable PCM/MPI or GCI; supports 8 kHz frame sync, 256 kHz–8.192 MHz clocks, and 5-V tolerant control pins |
| Codec Format | Programmable 8-bit A-law/µ-law or 16-bit linear two's-complement PCM; software-defined filter coefficients |
| Analog Inputs | Per-channel metallic (VIMT) and longitudinal (VILG) current sensing, DC voltage (VSAB), and high-level control (VHL) |
| Ringing Support | Integrated ring-trip detection with manual/automatic mode; compatible with internal or external ringing generators |
| Compliance | Meets GR-909, GR-844, LSSGR, and ITU-T central office requirements for voice line interface |
Pinout & Package
LE79Q2281DVC is housed in a 64-pin Thin Quad Flat Pack (TQFP), RoHS-compliant green package, tray-packed. Pin functions are validated per Zarlink Document #081256 (Rev G, Sep 2007), Figure 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VOUT1–VOUT4 | Analog output | Low-level voice signal outputs (per channel) to VE790-series ISLIC devices |
| VIN1–VIN4 | Analog input | Four-wire receive path analog inputs from ISLIC devices |
| VHL1–VHL4 | Control voltage output | High-level control signals for ISLIC DC feed, ringing, and metering (12/16 kHz) |
| VILG1–VILG4 | Analog sense input | Longitudinal loop current sensing (via RLG resistors) per channel |
| VIMT1–VIMT4 | Analog sense input | Metallic loop current sensing (via RMT resistors) per channel |
| LD1–LD4 | Tri-level control output | Selects ISLIC register destination (mode vs. relay latch) for P1–P3 signals |
| P1–P3 | Mode control output | Three-bit bus configuring VE790-series ISLIC operating modes (e.g., feed, ringing, test) |
| CS/RST | Control input | Chip select (short low pulse) or reset (≥16 DCLK cycles or ≥1 µs in GCI mode); 5-V tolerant |
| DIO/S1 | Serial I/O | PCM-mode bidirectional control data port (MSB-first); available only on 64-pin TQFP |
| INT | Interrupt output | Open-drain or TTL-compatible line indicating line event (off-hook, ring-trip, ground-key) |
Key Features
| Feature | Design Value |
|---|---|
| Software-programmable BORSCHT | Fully configurable DC feed current limit, feed resistance, polarity reversal (smooth/abrupt), and supervision thresholds per channel |
| Adaptive transhybrid balance | Continuous or "adapt-and-freeze" digital balancing to minimize echo across varying line impedances |
| Integrated line diagnostics | On-chip measurement of leakage resistance, line/ringer capacitance, and loop resistance-meets GR-909/GR-844 test requirements |
| Tone generation engine | Hardware-accelerated DTMF, FSK, random noise, and arbitrary tone synthesis with envelope shaping for metering (12/16 kHz) |
| VE790-series SLIC co-processor | Dedicated control logic for VE790 ISLIC devices including tri-level LD signaling, P1–P3 mode selection, and analog feedback interpretation |
Applications
| VoIP Integrated Access Device (IAD) | Cable Modem Telephony (NIU) |
|---|---|
Use Scenario: Residential gateway aggregating POTS lines over Ethernet/DSL with remote provisioning. IC Role / Device Role / Timing Role: Primary DSP and SLIC controller managing all four BORSCHT functions, PCM framing, and real-time loop supervision. Use Value: Enables single-hardware design supporting multiple country-specific ringing waveforms, DC feed profiles, and supervision thresholds via software configuration. |
Use Scenario: Cable operator node interface unit delivering POTS service over HFC network with embedded voice stack. IC Role / Device Role / Timing Role: Voice line interface controller coordinating with external VE790 ISLIC for battery feed, ringing, and fault detection. Use Value: Provides integrated ring-trip detection and programmable ground-key filters compliant with DOCSIS telephony specifications. |
| Fiber-to-the-Home (FTTH) Terminal | Intelligent PBX Line Card |
Use Scenario: GPON ONT providing analog telephone ports with local battery backup and remote diagnostics. IC Role / Device Role / Timing Role: Four-channel audio processor handling codec, hybrid balance, and line testing while interfacing to external ringing generator. Use Value: Supports external ringing with synchronized zero-crossing relay control and built-in leakage/capacitance measurement for field-deployed diagnostics. |
Use Scenario: Enterprise-grade PBX line card requiring loop-start/ground-start signaling and caller ID tone generation. IC Role / Device Role / Timing Role: Central ISLAC controller executing DTMF detection, CID tone synthesis, and off-hook debounce with programmable timing. Use Value: Delivers Caller Number Identification (CID) tone generation and adaptive hybrid balance meeting LSSGR echo return loss standards. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad-channel voice line interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LE79Q2284MVC | 80-pin LQFP package; adds DIN/S1, DOUT, DRB, DXB, GS1x/GS2x, and I/O1–I/O4 pins not present on LE79Q2281DVC | Supports expanded I/O control, additional serial interface options, and gain-select nodes for higher-precision analog sensing | Select LE79Q2284MVC when board layout requires extra general-purpose I/O or dual-data-path PCM/GCI flexibility. |
| LE79228-AB | Same die functionality but obsolete ordering part number; identical 64-pin TQFP package and pinout to LE79Q2281DVC | No functional or application difference; superseded by LE79Q2281DVC per Zarlink ordering documentation | LE79Q2281DVC is the current production variant; LE79228-AB is no longer orderable and lacks RoHS compliance assurance. |
Compared with LE79Q2284MVC, LE79Q2281DVC offers compact 64-pin TQFP integration ideal for space-constrained IADs, while LE79228-AB represents an obsolete predecessor with identical function but outdated compliance status-making LE79Q2281DVC the recommended choice for new designs requiring RoHS and long-term supply stability.
Availability
LE79Q2281DVC is available at Aetrix Electronics and suitable for VoIP IADs, cable telephony NIUs, FTTH terminals, and intelligent PBX line cards requiring stable component supply, RoHS compliance, and dual-interface (PCM/GCI) flexibility.
Supply support for LE79Q2281DVC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Zarlink Semiconductor was a fabless provider of communications ICs, acquired by Microsemi in 2011 and later integrated into Microchip Technology. It specialized in voice, timing, and broadband access solutions.
The LE79Q2281DVC belongs to the Le79228 Quad ISLAC™ product line, engineered specifically to serve as the programmable DSP and control hub in dual-chip voice line card architectures with VE790-series ISLIC devices-targeting global telephony infrastructure requiring software-defined BORSCHT compliance.
FAQ
What is the primary system role of the LE79Q2281DVC in a voice line card?
The LE79Q2281DVC acts as the intelligent audio-processing controller in a two-chip voice line card architecture, performing all digital signal processing (codec, filtering, tone generation), BORSCHT function management, and real-time control of companion VE790-series ISLIC devices. It does not drive the subscriber line directly but coordinates analog functions via dedicated control outputs (VHL, LD, P1–P3) and sense inputs (VILG, VIMT). This role is confirmed in the Product Description section of Zarlink Document #081256.
Does the LE79Q2281DVC support both PCM and GCI digital interfaces?
Yes, the LE79Q2281DVC supports selectable PCM/MPI or GCI operation, determined by signal presence on FS/DCL and PCLK/FS pins. In PCM mode, it accepts 8 kHz frame sync and supports master clock frequencies from 512 kHz to 8.192 MHz. In GCI mode, it operates at 2 MHz data rate with DCL = 2 or 4 MHz. Both modes use 5-V tolerant pins and share the same physical interface structure, as detailed in the Electrical Characteristics and Switching Characteristics sections of the datasheet.
What are the key analog inputs and outputs required to interface the LE79Q2281DVC with a VE790-series ISLIC?
The LE79Q2281DVC requires per-channel analog connections to the VE790-series ISLIC: VOUTi (low-level voice output), VINi (receive input), VHLi (high-level control for feed/ringing/metering), VILGi and VIMTi (longitudinal/metallic current sense), VSABi (DC voltage sense), and XSBi (battery sense). Outputs LD1–LD4 and P1–P3 provide tri-level mode and relay control. These signal relationships are defined in the Block Diagram and Pin Descriptions of Document #081256.
How does the LE79Q2281DVC handle ring-trip detection?
The LE79Q2281DVC integrates hardware ring-trip detection with programmable thresholds and supports both automatic and manual modes. It monitors analog inputs from the VE790-series ISLIC (e.g., VHL, VSAB) to detect current/voltage anomalies during ringing, then asserts the INT pin to signal the host processor. Configuration is done via registers controlling sensitivity and response timing, and the feature is validated per GR-909 test requirements as stated in the Features and Electrical Characteristics sections.
Is WinSLAC™ software required to configure the LE79Q2281DVC?
WinSLAC™ is not mandatory but strongly recommended for efficient configuration: it computes filter coefficients, DC-feed parameters, supervision thresholds, and equalization settings based on target line characteristics (e.g., loop length, gauge, country profile), then generates register values for direct loading. While registers can be programmed manually, WinSLAC™ eliminates error-prone calculation and enables rapid validation of predicted performance-confirmed in the Optional VCP Features and Product Description sections of the datasheet.
LE79Q2281DVC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 64-TQFP
- Packaging:
- Tray
- Product Status:
- Obsolete
- Function:
- ISLAC DEVICE
- Interface:
- PCM
- Number of Circuits:
- 4
- Voltage - Supply:
- 3.3V
- Current - Supply:
- -
- Power (Watts):
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-TQFP (10x10)
LE79Q2281DVC FAQ
1.How can I place an order for LE79Q2281DVC through Aetrix?
Please submit a Request for Quotation (RFQ) for LE79Q2281DVC on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LE79Q2281DVC reliable?
The price and inventory of LE79Q2281DVC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LE79Q2281DVC is usually 5 days.
3.What payment methods are accepted for LE79Q2281DVC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LE79Q2281DVC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LE79Q2281DVC?
LE79Q2281DVC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LE79Q2281DVC order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LE79Q2281DVC?
For technical support, including LE79Q2281DVC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LE79Q2281DVC requirements.
6.How does Aetrix verify that LE79Q2281DVC is sourced from the original manufacturer or authorized distributors?
All LE79Q2281DVC products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LE79Q2281DVC meets industry standards.
7.What is the process for return or replacement of LE79Q2281DVC?
All LE79Q2281DVC units undergo pre-shipment inspection (PSI). If there is an issue with LE79Q2281DVC, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LE79Q2281DVC part is unused and in its original packaging.
Return procedure for LE79Q2281DVC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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