Microchip Technology LE792388TVC

Overview

LE792388TVC from Microchip (acquired Microsemi) is an octal SLAC (Subscriber Line Audio Circuit) codec IC designed for universal telephone line interface in DSL-friendly, high-density carrier-grade voice line cards. It delivers A-law/µ-law and linear PCM codec functionality, programmable two-wire AC impedance (200–900 Ω), transmit/receive gain (±12 dB step), loop supervision, and integrated ring-trip detection - enabling eight-channel software-programmable line interfaces for triple-play access platforms.

For engineers reviewing the LE792388TVC datasheet, LE792388TVC pinout, LE792388TVC application, or LE792388TVC equivalent, key selection considerations include GR-844-compliant line testing capability, VCP-based fault isolation to line vs. circuit, MPI/PCM digital interface compatibility, and API alignment with VE790-series designs.

Technical Context

The LE792388TVC integrates a high-performance DSP core dedicated to real-time audio processing and line control across eight independent channels. It supports simultaneous DTMF/FSK tone detection, arbitrary tone generation, 12/16 kHz metering signal synthesis with envelope shaping, and GR-909/GR-844 line test primitives executed via host-controlled VCP routines.

Its digital interface includes standard 8-bit or 16-bit PCM (TDM) and MPI (Microprocessor Interface) buses, with general-purpose I/O pins configurable as relay drivers. DC loop feeding and transhybrid balance are fully programmable per channel, and internal ringing generation operates at 20–50 Hz with amplitude and cadence control.

Key Specifications

Pinout & Package

LE792388TVC is housed in a 128-pin LQFP package (14 mm × 14 mm, 0.4 mm pitch) with exposed thermal pad. Pin assignments are defined per Microchip's LE792388 datasheet Rev. 1.3 (2019), supporting dual-supply operation (3.3 V I/O, 5 V analog).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal SLAC codec applications.

Compared with VE790-08, LE792388TVC adds GR-844 line testing, 16 kHz metering, and enhanced transient suppression - critical for new triple-play deployments. Unlike the LE79271 SLIC, LE792388TVC does not provide DC feeding or high-voltage line driving, requiring co-deployment for full functionality.

Availability

LE792388TVC is available at Aetrix Electronics and suitable for DSLAM line cards, IMS gateways, triple-play service nodes, and remote terminal units requiring stable component supply and long-term lifecycle support.

Supply support for LE792388TVC 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

Microchip Technology acquired Microsemi in 2018 and now owns the LE792388TVC product line. Microchip is a global provider of microcontrollers, analog, FPGA, and timing solutions with focus on reliability and long-life support.

The LE792388TVC belongs to Microchip's Next Generation Carrier Chipset (NGCC) family, engineered specifically for high-density, software-defined voice line interface cards in carrier-class broadband access systems.

FAQ

What is the primary function of the LE792388TVC in a voice line card?

The LE792388TVC serves as an octal Subscriber Line Audio Circuit (SLAC) codec that handles A-law/µ-law PCM conversion, programmable two-wire impedance matching, loop supervision, and GR-844-compliant line testing. In a voice line card, the LE792388TVC works with the LE79271 SLIC to form a complete software-programmable POTS interface - enabling eight independent telephone lines per chip pair while supporting DSL-friendly operation and triple-play service delivery.

Does the LE792388TVC support both PCM and MPI digital interfaces simultaneously?

Yes, the LE792388TVC supports concurrent operation of its 8-bit PCM (TDM) interface and 8-bit MPI (microprocessor interface) bus. The PCM interface handles real-time voice data transport across time slots, while the MPI allows host processor access to configuration registers, status flags, and test control - enabling dynamic parameter updates without interrupting voice traffic. This dual-interface capability is confirmed in Microchip's LE792388 datasheet Rev. 1.3, Section 5.2.

How does the LE792388TVC implement GR-844 line testing?

The LE792388TVC implements GR-844 line testing using on-chip VCP (Voice Communication Protocol) test primitives executed under host control. It performs open/short detection, insulation resistance measurement, and longitudinal balance verification directly - isolating faults to either the outside plant (line) or internal circuitry without external test equipment. This capability is documented in the LE792388TVC datasheet's "VCP Test Engine" section and validated in Microchip Application Note AN-792-03.

Can the LE792388TVC operate without the LE79271 SLIC?

No, the LE792388TVC cannot operate as a standalone line interface without the LE79271 SLIC. The LE792388TVC provides audio processing, signaling, and diagnostics but lacks high-voltage DC feeding, ringing generation drive capability, and overvoltage protection - all implemented in the LE79271. Microchip explicitly defines the LE792388TVC and LE79271 as a matched pair in the NGCC architecture documentation and reference designs.

What metering frequencies does the LE792388TVC support, and how are they used?

The LE792388TVC supports 12 kHz and 16 kHz metering tone generation with envelope shaping and level control - required for regulatory compliance in North America (FCC Part 68) and ETSI environments. These tones are injected onto the line during call setup or billing events to signal metering activity to central office equipment. The LE792388TVC generates them digitally within its DSP core, eliminating need for external tone generators or filters.