Renesas 72V8980JG8

Overview

72V8980JG8 from IDT (now Renesas Electronics) is a 3.3 V, 256 × 256 non-blocking time slot interchange (TSI) digital switch for ST-BUS®-compliant telecom systems. It features eight 2.048 Mb/s serial RX inputs and eight TX outputs, microprocessor interface (8-bit data bus), 3.3 V I/O with 5 V tolerant inputs, and operates from –40°C to +85°C. It is used in digital cross-connect systems and TDM multiplexers requiring channel-level switching.

For engineers reviewing the 72V8980JG8 datasheet, 72V8980JG8 pinout, 72V8980JG8 application, or 72V8980JG8 equivalent, key selection considerations include ST-BUS® frame alignment (F0i, C4i), per-channel connection memory control (CMH/CML), ODE-driven output enable, DTA handshake timing, and PLCC-44 package compatibility with legacy telecom PCB layouts.

Technical Context

The 72V8980JG8 implements a dual-mode switching architecture: Connection Mode routes Data Memory contents via Connection Memory Low (CML) address pointers, while Processor Mode directly outputs CML contents on TX streams. Its internal serial-to-parallel and parallel-to-serial converters synchronize to 4.096 MHz C4i and 8 kHz F0i, enabling precise 125 µs frame-aligned time slot routing.

Control is managed through a 6-bit address bus (A0–A5) and an 8-bit bidirectional data bus (D0–D7), with A5 selecting between Control Register (A5 = 0) and memory-mapped access (A5 = 1). The ODE input provides master three-state control over all eight TX outputs, independent of per-channel CMH bit 0 settings.

Key Specifications

Pinout & Package

72V8980JG8 is packaged in a 44-pin Plastic Leaded Chip Carrier (PLCC, J44-1), 0.65 in × 0.65 in, 0.05 in pitch. Pin 1 index corner is marked with a dot; pin numbering is counterclockwise from index.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar time slot interchange applications.

Compared with 72V8980PV8 and 72V8980DB8, the 72V8980JG8 offers proven mechanical reliability in PLCC sockets, simplified power-up sequencing (no RESET pin dependency), and long-term availability in telecom-qualified PLCC form factor - making it optimal for field-replaceable modules and legacy system upgrades.

Availability

72V8980JG8 is available at Aetrix Electronics and suitable for digital cross-connect systems, TDM multiplexers, ISDN PRI gateways, and VoIP telephony backplanes requiring stable component supply and long-lifecycle support.

Supply support for 72V8980JG8 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

IDT (Integrated Device Technology), now part of Renesas Electronics, is a semiconductor company specializing in timing, memory interface, and telecom ICs with deep expertise in TDM and packet-switched infrastructure.

The IDT72V8980 product line was designed specifically for ST-BUS®-based time division multiplexing applications in carrier-grade and enterprise telecom equipment, emphasizing frame-aligned switching, low-latency routing, and robust MPU interfacing.

FAQ

What is the function of the DTA pin on the 72V8980JG8?

The DTA (Data Acknowledgment) pin on the 72V8980JG8 is an open-drain, active-low output that signals completion of a microprocessor read or write cycle. It requires an external pull-up resistor and is used to synchronize firmware operations without fixed wait states. This handshake mechanism ensures reliable data transfer timing between the host MPU and the 72V8980JG8's internal register and memory blocks.

Does the 72V8980JG8 support both Connection Mode and Processor Mode switching?

Yes, the 72V8980JG8 supports both Connection Mode and Processor Mode. In Connection Mode, Connection Memory Low (CML) entries act as addresses pointing to Data Memory locations for routing. In Processor Mode, CML contents are output directly on TX streams. Mode selection is controlled by bit 6 (PE) of the Control Register and per-channel bit 2 (CS) in Connection Memory High - enabling hybrid configurations per channel.

Is the RESET pin available on the 72V8980JG8 PLCC package?

No, the RESET pin is not available on the 72V8980JG8 PLCC package. Per the datasheet, RESET is only provided on the SSOP-48 variant (e.g., 72V8980PV8). For the 72V8980JG8, safe initialization relies on proper power sequencing and use of the ODE pin to hold TX outputs in high-impedance until Connection Memory High is fully programmed.

What timing signals are required for basic operation of the 72V8980JG8?

The 72V8980JG8 requires two critical timing inputs: C4i (4.096 MHz serial clock) for shifting data in/out of serial streams, and F0i (8 kHz frame pulse) for synchronizing 125 µs ST-BUS® frames. Both signals must be present and stable before enabling ODE or initiating MPU access; absence of either causes loss of frame alignment and invalid switching behavior.

How does the ODE pin affect output behavior on the 72V8980JG8?

The ODE (Output Drive Enable) pin on the 72V8980JG8 acts as a master enable for all eight TX outputs. When ODE is LOW, TX0–TX7 are forced into high-impedance regardless of Connection Memory High programming. When ODE is HIGH, per-channel output enable is controlled by bit 0 of each CMH location - allowing selective channel activation without affecting others.