LE79R79-1FQC

Telecom Overview

The LE79R79-1FQC is a bipolar monolithic Ringing Subscriber Line Interface Circuit (SLIC) from the VE580 Series, manufactured by Microchip Technology. It integrates on-chip ringing and battery switching to support short-loop applications. The device operates with VBAT1 ranging from -40.5V to -75V and VBAT2 from -19V to VBAT1. It provides a current gain of 1000 and features a longitudinal balance of 52 dB with polarity reversal capability. Packaged in a 32-pin QFN, it includes an internal VEE regulator, eliminating the need for external negative voltage supplies.

Telecom Feature Summary

• Integrates trapezoidal ringing generation and ring-trip detection on-chip
• Features dual-battery switching to optimize power consumption between active and standby states
• Supports programmable constant-current feed and open-circuit voltage adjustment
• Includes two on-chip relay drivers and ground-key detection functionality

Telecom Applications

• ISDN Terminal Adaptors (TA)
• Integrated Access Devices (IADs)
• Network Interface Units (NIUs)
• Voice over ISDN or T1/E1 systems
• Smart Residential Gateways

Telecom Procurement Notes

Verify component authenticity through authorized Microchip distributors or certified suppliers. Confirm the specific ordering suffix matches the required package type and performance grade. Request official datasheets and compliance documentation to ensure alignment with project specifications before finalizing acquisition.

Telecom Selection Notes

Select the LE79R79-1FQC for designs requiring integrated ringing without external components. Ensure the application supports the specified bipolar voltage ranges and utilizes the 32-pin QFN footprint. Verify that the 52 dB longitudinal balance meets the system's transmission requirements and that polarity reversal is necessary for the interface logic.

Telecom Part Context

This component belongs to the Zarlink VE580 series of subscriber line interface circuits, now produced under the Microchip Technology brand. It is designed to replace discrete SLIC solutions by consolidating BORSHT functions into a single monolithic die, reducing board space and component count for telephony interfaces.

Telecom Replacement Considerations

LE79R79-2FQC offers 63 dB longitudinal balance. LE79R79-3DJC provides PLCC packaging. LE79R79-1DJC is the PLCC equivalent with 52 dB balance.