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Microchip Technology LE79R241DJC
- Part No.:
- LE79R241DJC
- Manufacturer:
- Microchip Technology
- Category:
- Telecom
- Package:
- 32-LCC (J-Lead)
- Datasheet:
-
LE79R241DJC.pdf
- Description:
- IC TELECOM INTERFACE 32PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,584
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Product details
Overview
LE79R241DJC from Zarlink Semiconductor is an Intelligent Subscriber Line Interface Circuit (ISLIC™) designed for telephony line cards, providing full BORSCHT functionality with programmable DC feed, ringing, supervision, diagnostics, and thermal management. It operates with dual battery supplies (–42.5 V to –99 V), supports 12 kHz/16 kHz metering, drives up to 7 kft of 24-gauge wire, and integrates three relay drivers for test load switching.
For engineers reviewing the LE79R241DJC datasheet, LE79R241DJC pinout, LE79R241DJC application, or LE79R241DJC equivalent, this device is critical for designing software-configurable POTS line interfaces in CO, DLC, PBX/KTS, and pair-gain systems requiring precise loop-current control, foreign voltage detection, and integrated line diagnostics.
Technical Context
The LE79R241DJC implements a linear, bipolar-based loop-current feeding architecture controlled via tri-level LD/P1–P3 interface from a VE790-series ISLAC™ companion IC. It monitors metallic (IMT) and longitudinal (ILG) currents, AC (VTX) and DC (VSAB) line voltages, and provides analog feedback for real-time supervision and diagnostics.
Its thermal management uses external resistors (TMP/TMS/TMN/VBL) to offload power dissipation, enabling stable operation under high-loop-resistance conditions. The device supports smooth polarity reversal, tip-open ground-start signaling, and programmable off-hook/ground-key thresholds - all configurable via the VE790 series DSP core.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Battery Supply Range | VBH: –42.5 V to –99 V; VBL: –15 V to VBH - enables long- and short-loop operation across US/EU standards. |
| DC Loop Current Limit | Programmable up to 25 mA - ensures stable feed independent of battery voltage via intelligent current-limit behavior. |
| Ringing Drive Capability | Supports internal/external ringing; drives 4.4 kft (26 AWG) or 7 kft (24 AWG) - meets LSSGR and CCITT central office requirements. |
| Line Diagnostics | Measures leakage resistance, loop resistance, line capacitance, bell capacitance, foreign voltage - eliminates need for external test hardware. |
| Thermal Management | Uses TMP/TMS/TMN pins with external resistors to shift >50% of power dissipation off-die - extends reliability at junction temperatures up to 145 °C. |
| Relay Drivers | Three integrated open-collector drivers (R1–R3) with RYE emitter reference - configurable as test load switches or relay controls without external transistors. |
| Operating Temperature | –40 °C to +85 °C industrial range - qualified per Bellcore GR-357-CORE for telecom infrastructure deployment. |
Pinout & Package
LE79R241DJC is housed in a 32-pin PLCC (Plastic Leaded Chip Carrier) package with lead-free green finish compliant with RoHS Directive 2002/95/EC. The package features standard pin pitch and surface-mount compatibility with SnPb or lead-free reflow profiles (peak ≤245 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| AD / BD | Subscriber loop current outputs | Drive A/B leads of two-wire interface; support ±150 mA continuous current for BORSCHT functions. |
| SA / SB | Line voltage sense inputs | Monitor voltages across fuse resistors; protected against lightning/power-cross with external RSA/RSP. |
| IMT / ILG | Analog current monitoring outputs | IMT ∝ (IAD + IBD); ILG ∝ (IAD – IBD); used by VE790 for real-time loop diagnostics and thermal overload indication. |
| VTX / VSAB | AC/DC line voltage outputs | VTX = scaled AC component (voice path); VSAB = scaled DC voltage between SA/SB - feed codec interface for supervision. |
| P1–P3 / LD | Tri-level mode/control latch inputs | LD selects function: logic-1 → mode decode (P1–P3); logic-0 → relay driver control; ~VREF → lock register - enables single-bus configuration. |
| R1 / R2 / R3 / RYE | Relay/test load driver outputs | R1 collector to BGND; R2/R3 collectors to RYE; RYE tied to relay ground - supports up to three independent load switches. |
| VBH / VBL / BGND | Dual battery supply terminals | VBH powers ringing/long loops; VBL powers short loops; BGND is common return - enables dual-battery power saving and automatic switching. |
| VLB / VREF | Longitudinal bias & reference inputs | VLB sets longitudinal operating point (0 V to VREF → linear voltage scaling); VREF is analog reference from VE790 - enables software-controlled longitudinal balance. |
Key Features
| Feature | Design Value |
|---|---|
| Programmable DC feed characteristics | Independent of battery voltage, current-limited, and software-adjustable feed resistance - ensures consistent loop performance across aging batteries and varying loop lengths. |
| Integrated subscriber line diagnostics | On-chip measurement of leakage resistance, loop resistance, line/bell capacitance, and foreign voltage - replaces manual test equipment in remote DLC or PBX deployments. |
| Intelligent thermal management | External resistor network (TMP/TMS/TMN/VBL) shifts thermal load away from die - maintains reliability during sustained off-hook or high-capacitance ring conditions. |
| Smooth polarity reversal | Controlled transition between battery polarities without transient spikes - prevents false disconnect detection and protects connected telephones. |
| Metering capability (12/16 kHz) | Generates trapezoidal 5 REN metering signal with DC offset - satisfies North American and European regulatory requirements for call accounting. |
| Tip-open state for ground-start signaling | Enables tip conductor to float while maintaining battery continuity - supports legacy ground-start CO lines without external relays. |
Applications
| Central Office (CO) Line Card | Digital Loop Carrier (DLC) |
|---|---|
|
Use Scenario: High-density line card serving 16–32 subscribers in a Class 5 switch environment with mixed loop lengths and international signaling requirements. IC Role / Device Role / Timing Role: Primary ISLIC providing BORSCHT functions, supervised by VE790 ISLAC for real-time parameter updates and diagnostics. Use Value: Software-programmable ring frequency, off-hook threshold, and feed resistance eliminate hardware variants - reduces inventory and accelerates certification for regional deployments. |
Use Scenario: Remote terminal unit delivering POTS service over fiber-fed copper pairs in rural or suburban areas with loop lengths exceeding 5 kft. IC Role / Device Role / Timing Role: High-voltage bipolar ISLIC driving long loops using VBH supply; thermal management handles sustained off-hook loads on high-capacitance lines. Use Value: Dual-battery operation and intelligent thermal offloading enable reliable 24/7 service without forced air cooling or oversized heatsinks. |
| PBX / Key Telephone System (KTS) | Pair Gain Systems |
|
Use Scenario: Enterprise-grade PBX supporting analog extensions with integrated test capabilities for maintenance without technician dispatch. IC Role / Device Role / Timing Role: Line interface IC performing automated line tests (leakage, capacitance, foreign voltage) triggered via VE790 command interface. Use Value: Built-in diagnostics reduce mean time to repair (MTTR) by 70% compared to external test sets - critical for unstaffed remote sites. |
Use Scenario: DSLAM co-location cabinet where multiple POTS lines share copper pairs with broadband services, requiring precise longitudinal balance and noise immunity. IC Role / Device Role / Timing Role: ISLIC maintaining longitudinal balance via VLB-controlled offset and IMT/ILG feedback - suppresses crosstalk into adjacent DSL channels. Use Value: Programmable longitudinal operating point and feed resistance optimize noise margin for both voice and data services on shared infrastructure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar subscriber line interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LE79R251QC | QFN-32 package (vs. PLCC-32), higher thermal efficiency (25 °C/W vs. 45 °C/W), same functional spec - no change to VE790 interface or firmware. | Preferred for space-constrained, high-density line cards requiring improved thermal performance without layout redesign. | Select LE79R251QC when board area and thermal headroom are limiting; retains identical software and peripheral design. |
| LE79231JC | PLCC-32, lower maximum battery voltage (–70 V vs. –99 V), reduced ringing drive (up to 5.5 kft 24 AWG), no R3 relay driver - fewer diagnostic features. | Suitable for shorter-loop CO or enterprise PBX applications where full long-loop capability is unnecessary. | Choose LE79231JC only for cost-sensitive, low-complexity deployments with loop lengths < 4 kft and no requirement for triple relay control. |
Compared with LE79R241DJC, LE79R251QC offers superior thermal performance in a smaller footprint but requires QFN assembly; LE79231JC reduces feature set and voltage range to lower cost - neither is pin-compatible, and both require validation of battery interface, relay routing, and diagnostic firmware.
Availability
LE79R241DJC is available at Aetrix Electronics and suitable for Central Office line cards, Digital Loop Carrier systems, and PBX/KTS deployments requiring stable component supply, long-term lifecycle support, and RoHS-compliant green packaging.
Supply support for LE79R241DJC 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 semiconductor company specializing in voice, timing, and RF solutions for telecommunications infrastructure, acquired by Microsemi in 2011. Its products targeted carrier-grade reliability and programmability.
The LE79R241DJC belongs to Zarlink's VE790-series voice chipset, designed specifically for software-configurable, multi-country POTS line interface cards requiring full BORSCHT implementation with integrated diagnostics and thermal resilience.
FAQ
What is the primary function of the LE79R241DJC in a telephony line card?
The LE79R241DJC serves as the Intelligent Subscriber Line Interface Circuit (ISLIC™), delivering full BORSCHT functionality - battery feed, overvoltage protection, ringing, supervision, coding, hybrid, and testing - for analog telephone line interfaces. It works exclusively with VE790-series ISLAC™ devices to provide software-programmable control of loop current, ringing, diagnostics, and thermal management in CO, DLC, and PBX systems.
Does the LE79R241DJC support both US and European telephony standards?
Yes, the LE79R241DJC supports both US and European standards through software configuration via its VE790-series companion IC. It drives ring up to 7 kft of 24 AWG wire (US) or 1.7 km of 0.5 mm copper cable (EU), and supports programmable ringing waveforms, off-hook thresholds, and DC-feed parameters to meet LSSGR, CCITT, and national regulatory requirements without hardware changes.
How does thermal management work in the LE79R241DJC?
The LE79R241DJC uses external resistors connected to TMP, TMS, and TMN pins to offload power dissipation from the die. By shifting thermal load to these external components, it maintains junction temperature below 145 °C even under sustained off-hook or high-capacitance ringing conditions. This intelligent thermal management extends reliability and eliminates need for active cooling in dense line cards.
Can the LE79R241DJC operate with a single battery supply?
Yes, the LE79R241DJC supports single-battery operation: VBH and VBL can be tied together when only one battery rail is available. In this configuration, the device automatically selects appropriate internal paths for short- or long-loop operation, and retains full functionality including programmable feed, diagnostics, and relay control - though peak ringing performance is limited compared to dual-rail use.
What diagnostic capabilities does the LE79R241DJC provide?
The LE79R241DJC provides integrated diagnostics for leakage resistance, loop resistance, line capacitance, bell capacitance, and foreign voltage sensing - all measured internally and reported via analog outputs (IMT, ILG, VTX, VSAB) to the VE790-series ISLAC™. These measurements enable automated fault isolation in remote locations without external test equipment, reducing field service costs and downtime.
LE79R241DJC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 32-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Subscriber Line Interface Concept (SLIC)
- Interface:
- 2-Wire
- Number of Circuits:
- 1
- Voltage - Supply:
- 5V
- Current - Supply:
- -
- Power (Watts):
- -
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-PLCC (11.43x13.97)
LE79R241DJC FAQ
1.How can I place an order for LE79R241DJC through Aetrix?
Please submit a Request for Quotation (RFQ) for LE79R241DJC 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 LE79R241DJC reliable?
The price and inventory of LE79R241DJC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LE79R241DJC is usually 5 days.
3.What payment methods are accepted for LE79R241DJC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LE79R241DJC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LE79R241DJC?
LE79R241DJC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LE79R241DJC 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 LE79R241DJC?
For technical support, including LE79R241DJC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LE79R241DJC requirements.
6.How does Aetrix verify that LE79R241DJC is sourced from the original manufacturer or authorized distributors?
All LE79R241DJC 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 LE79R241DJC meets industry standards.
7.What is the process for return or replacement of LE79R241DJC?
All LE79R241DJC units undergo pre-shipment inspection (PSI). If there is an issue with LE79R241DJC, 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 LE79R241DJC part is unused and in its original packaging.
Return procedure for LE79R241DJC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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