Renesas 7290820JG

Overview

IDT7290820JG from Integrated Device Technology, Inc. is a 5V non-blocking time slot interchange (TSI) digital switch with 2,048 × 2,048 channel capacity at 8.192 Mb/s, supporting ST-BUS®/GCI and WFP frame alignment modes, per-channel variable/constant throughput delay control, and IEEE-1149.1 JTAG test port - deployed in telecom voice/data multiplexing systems requiring precise PCM time-slot routing.

For engineers reviewing the IDT7290820JG datasheet, IDT7290820JG pinout, IDT7290820JG application, or IDT7290820JG equivalent, key selection considerations include serial data rate configuration (2.048/4.096/8.192 Mb/s), microprocessor interface mode (Intel/Motorola multiplexed or non-multiplexed), per-channel high-impedance output control via ODE and connection memory, and frame offset calibration for multi-chip synchronization.

Technical Context

The IDT7290820JG implements a dual-mode TSI architecture with separate data memory (up to 2,048 bytes) and connection memory (16 streams × 128 channels × 16 bits), enabling both Connection Mode (source-address-based switching) and Processor Mode (direct data write to TX outputs). Its timing unit supports automatic ST-BUS®/GCI frame format detection and programmable input frame offset calibration using FE/HCLK.

Switching throughput delay is configurable per channel: Variable Delay mode achieves minimum 3-time-slot latency for voice, while Constant Delay mode guarantees fixed 1-frame (125 µs) latency with frame integrity for concatenated data. The device uses a master clock (CLK) at exactly 2× the serial bit rate (4.096/8.192/16.384 MHz) and provides full JTAG boundary scan via TDI/TDO/TCK/TRST/TMS pins.

Key Specifications

Pinout & Package

Package: 84-pin Plastic Leaded Chip Carrier (PLCC), 0.05″ pitch, 1.15″ × 1.15″ (order code J). Pin 1 marked by index notch; IC pin tied to GND for normal operation and IEEE-1149.1 compliance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7290820JG, IDT7290810JG reduces channel count and feature set for cost-sensitive deployments, while CY7C9245AV-10JC trades integrated frame handling and testability for raw microport speed and voltage flexibility - neither offers pin compatibility or drop-in replacement capability.

Availability

IDT7290820JG is available at Aetrix Electronics and suitable for telecom central office switching, digital loop carrier systems, VoIP gateway media processing, and industrial TDM backplane interconnect requiring stable component supply across long-lifecycle deployments.

Supply support for IDT7290820JG 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) is a fabless semiconductor company specializing in timing, RF, memory interface, and real-time interconnect solutions for communications and computing infrastructure.

IDT7290820JG belongs to IDT's legacy TSI digital switch product line, designed specifically for carrier-grade time-division multiplexing systems requiring non-blocking, low-jitter, frame-aligned PCM channel switching with embedded diagnostics and testability.

FAQ

What is the maximum serial data rate supported by the IDT7290820JG?

The IDT7290820JG supports a maximum serial data rate of 8.192 Mb/s, enabling full 2,048 × 2,048 channel non-blocking switching. At this rate, it processes 128 time-slots per 125 µs frame with a required master clock (CLK) of 16.384 MHz. Lower rates - 4.096 Mb/s (64 slots/frame) and 2.048 Mb/s (32 slots/frame) - are also supported via DR0–DR1 register bits.

How does the IDT7290820JG handle frame synchronization for ST-BUS® and GCI interfaces?

The IDT7290820JG automatically detects and identifies ST-BUS® or GCI frame formats on the F0i input by analyzing frame pulse polarity and bit-clock edge alignment. In ST-BUS® mode, it samples data on the rising edge of CLK; in GCI mode, on the falling edge. This eliminates manual configuration and ensures interoperability with diverse line interface units without firmware changes.

Can the IDT7290820JG operate in both Connection Mode and Processor Mode simultaneously?

No - the IDT7290820JG operates in either Connection Mode or Processor Mode per output channel, controlled by the PC (Processor Channel) bit in each connection memory location. When PC = 0, the device reads source addresses (SAB/CAB) from connection memory to route data from data memory; when PC = 1, it outputs the raw value stored in that connection memory location directly to the TX stream.

What is the function of the ODE pin on the IDT7290820JG?

The ODE (Output Drive Enable) pin on the IDT7290820JG is a global control input that enables or disables all TX0–TX15 serial output drivers. When ODE is LOW and the OSB bit in the IMS register is also LOW, all TX outputs enter high-impedance state - overriding individual per-channel settings. When ODE is HIGH, per-channel output control reverts to the OE bits in connection memory.

Does the IDT7290820JG support JTAG boundary scan, and how is it initialized?

Yes, the IDT7290820JG fully complies with IEEE-1149.1 JTAG boundary scan using TMS, TDI, TDO, TCK, and TRST pins. To ensure normal functional operation, TRST must be pulsed LOW on power-up or held LOW during reset; otherwise, the device may remain in test-logic-reset state and fail to initialize its internal registers and memories.