Renesas IDT72V8980J

Overview

IDT72V8980 from Integrated Device Technology, Inc. is a 3.3 V ST-BUS®-compatible digital time slot interchange (TSI) switch implementing a non-blocking 256 × 256 channel matrix for telecom TDM switching. It supports eight 2.048 Mb/s serial RX inputs and eight TX outputs, each carrying 32 × 64 Kbit/s channels, with microprocessor-controlled memory mapping, 3.3 V I/O, and 5 V tolerant inputs - deployed in digital PBX, voice gateways, and channelized E1/T1 multiplexers.

For engineers reviewing the IDT72V8980 datasheet, IDT72V8980 pinout, IDT72V8980 application, or IDT72V8980 equivalent, key selection considerations include ST-BUS® frame alignment (125 µs), C4i clock timing (4.096 MHz), per-channel output enable via Connection Memory HIGH, ODE-controlled three-state TX drivers, and support for both Processor Mode and Connection Mode data routing.

Technical Context

The IDT72V8980 implements dual-path internal memory architecture: 256-position Data Memory stores incoming serial data after serial-to-parallel conversion, while split Connection Memory (HIGH/LOW) defines per-channel routing logic. Frame synchronization is driven by F0i (8 kHz), and serial data streams are aligned to 125 µs frames containing 32 × 8-bit slots at 2.048 Mb/s.

Switching operation occurs in two distinct modes: Connection Mode uses Connection Memory LOW as address pointers into Data Memory for source selection, while Processor Mode directly outputs Connection Memory LOW contents on TX streams. Control is managed via an 8-bit microprocessor bus with A0–A5 addressing, CS/DS/R/W handshaking, and DTA acknowledgment - all operating under 3.3 V supply with 5 V tolerant digital inputs.

Key Specifications

Pinout & Package

Available in 44-pin PLCC (order code J), 48-pin SSOP (PV), and 44-pin PQFP (DB). The IDT72V8980J variant corresponds to the PLCC package (J44-1, 0.65 in × 0.65 in, 0.05 in pitch).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V8990 and MC145506, the IDT72V8980 uniquely balances industrial temperature operation, ST-BUS® native support, and full per-channel software control - making it the optimal choice for new 3.3 V telecom infrastructure designs requiring 256-channel scalability.

Availability

IDT72V8980 is available at Aetrix Electronics and suitable for digital PBX, voice gateway, and channelized E1/T1 multiplexer applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for telecom infrastructure programs.

Supply support for IDT72V8980 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

Integrated Device Technology, Inc. (IDT) was a U.S.-based semiconductor company specializing in timing, memory interface, RF, and telecom ICs before its acquisition by Renesas Electronics in 2019.

The IDT72V8980 belongs to IDT's time slot interchange product line, designed specifically for ST-BUS®-based TDM switching in carrier-grade voice infrastructure - emphasizing low-latency routing, per-channel configurability, and robust industrial temperature operation.

FAQ

What is the minimum achievable delay through the IDT72V8980 for time slot switching?

The IDT72V8980 achieves a minimum 2-time-slot delay for specific RX-to-TX stream combinations - for example, data entering on RX0 can appear on TX1 two time slots later. This delay arises from internal serial-to-parallel conversion, memory access, and parallel-to-serial reconstruction. The exact delay depends on input/output stream pairing and is documented in Table 1 of the IDT72V8980 datasheet.

Does the IDT72V8980 support both Connection Mode and Processor Mode simultaneously?

No - the IDT72V8980 operates in either Connection Mode or Processor Mode globally, controlled by the PE (Processor Enable) bit in the Control Register. When PE = 1, all TX channels output Connection Memory LOW contents; when PE = 0, per-channel behavior is determined by Connection Memory HIGH bit 2 (CS). Mixed-mode operation per channel is not supported.

What is the function of the CCO pin on the IDT72V8980, and how is it synchronized?

The CCO (Control Channel Output) pin on the IDT72V8980 outputs a 2.048 Mb/s serial stream carrying one control bit per time slot - sourced from bit 1 of each Connection Memory HIGH location. It is synchronized to the TX streams but transmitted one time slot early (e.g., CCO bit for TX0, CH0 appears during TX7, CH31), allowing external logic time to act on control data before associated payload arrives.

Is the RESET pin available on all IDT72V8980 package variants?

No - the RESET pin is only provided on the 48-pin SSOP (PV) package variant of the IDT72V8980. It is absent from the 44-pin PLCC (J) and 44-pin PQFP (DB) packages. For PLCC and PQFP versions, system-level reset must be managed externally via ODE pin assertion and software initialization sequence.

How does the IDT72V8980 handle 5 V logic interfacing on its control bus?

The IDT72V8980 features 5 V tolerant digital inputs (CS, DS, R/W, A0–A5, D0–D7, F0i, C4i, ODE), allowing direct connection to 5 V microcontrollers without level-shifting. Its 3.3 V supply (VCC) powers internal logic, while input voltage tolerance up to 5.25 V ensures compatibility with legacy 5 V control planes - a key enabler for mixed-voltage telecom system upgrades.