Renesas 71V2556SA133BGG8

Overview

71V2556SA133BGG8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit organization (4.5 Mbit), 166 MHz operation (3.5 ns clock-to-data access), pipelined outputs, and zero-bus-turnaround architecture for high-throughput memory subsystems in network packet buffers and telecom switching fabrics.

For engineers reviewing the 71V2556SA133BGG8 datasheet, 71V2556SA133BGG8 pinout, 71V2556SA133BGG8 application, or 71V2556SA133BGG8 equivalent, key selection criteria include burst-mode timing compliance, 2.5V I/O voltage tolerance, JTAG testability support, and BGA-119 package thermal/mechanical suitability for high-density PCB layouts.

Technical Context

This device implements a fully synchronous, clock-edge-triggered interface with address/data/control registers, an on-chip 4-word burst counter (linear or interleaved via LBO), and internally synchronized OE to eliminate external output-enable timing constraints. It supports depth expansion using three independent chip enables (CE1/CE2/CE2).

The architecture features individual byte-write control (BW1–BW4), clock enable (CEN) for cycle suspension, and optional IEEE 1149.1 JTAG boundary scan. All inputs are registered on the positive clock edge; data output is pipelined with deterministic 2-cycle latency from address load.

Key Specifications

Pinout & Package

71V2556SA133BGG8 is packaged in a JEDEC-standard 119-ball grid array (BGA), designated BGG119, with 1.27 mm ball pitch and Pb-free finish. The package supports automated optical inspection and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous SRAM applications.

Compared with CY7C1355BV33-133BZI and AS7C3256B-133BIN, the 71V2556SA133BGG8 delivers higher bandwidth (166 vs. 133 MHz), true zero-bus-turnaround operation, integrated burst counter, and JTAG testability - making it uniquely suited for latency-sensitive, high-reliability telecom and infrastructure memory subsystems.

Availability

71V2556SA133BGG8 is available at Aetrix Electronics and suitable for network packet buffers, telecom switch fabrics, base station baseband processing, and industrial real-time controllers requiring stable component supply across extended product lifecycles.

Supply support for 71V2556SA133BGG8 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 high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The 71V2556SA133BGG8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency memory subsystems in high-speed networking and telecom infrastructure where deterministic burst access and bus turnaround elimination are critical.

FAQ

What is the maximum operating frequency of the 71V2556SA133BGG8?

The 71V2556SA133BGG8 is rated for 166 MHz operation, corresponding to a 6.0 ns clock period and 3.5 ns clock-to-data access time. This frequency is guaranteed across the full industrial temperature range (–40°C to +85°C) and 3.3 V ±5% supply, enabling sustained 166 MT/s throughput in burst-mode applications.

Does the 71V2556SA133BGG8 support JTAG boundary scan?

Yes, the 71V2556SA133BGG8 (SA suffix) includes optional IEEE 1149.1-compliant JTAG boundary scan functionality. Pins TMS, TDI, TCK, TDO, and TRST are assigned on the BGA package and support structural testing, interconnect verification, and in-system programming diagnostics when enabled.

How does the ZBT™ architecture improve performance in the 71V2556SA133BGG8?

The ZBT™ (Zero Bus Turnaround) architecture in the 71V2556SA133BGG8 eliminates dead cycles between alternating read and write operations. By overlapping bus direction control with data transfer, it enables immediate back-to-back burst reads and writes - increasing effective bandwidth by up to 30% compared to conventional synchronous SRAMs in mixed-access workloads.

What is the function of the ADV/LD and LBO pins on the 71V2556SA133BGG8?

On the 71V2556SA133BGG8, ADV/LD controls the burst counter: LOW loads a new external address; HIGH increments the internal counter. LBO selects burst order - tied to VSS for linear sequence (0,1,2,3), or VDD for interleaved (0,2,1,3). Together they enable flexible, efficient 4-word burst addressing without external logic.

Can the 71V2556SA133BGG8 operate with different supply voltages for core and I/O?

Yes, the 71V2556SA133BGG8 uses separate supplies: VDD = 3.3 V ±5% for core logic and VDDQ = 2.5 V for I/O drivers. This dual-rail design isolates noise-sensitive I/O signaling from core switching activity and ensures compatibility with 2.5 V FPGA/ASIC interfaces while maintaining 3.3 V logic robustness.