Renesas 71V2556SA133BGI8

Overview

71V2556SA133BGI8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit organization (4.5 Mbit), 133 MHz operation (7.5 ns clock-to-data access), pipelined outputs, and zero-bus-turnaround architecture. It features 2.5V I/O supply, individual byte write control (BW1–BW4), three chip enables, and supports linear/interleaved 4-word burst modes in high-speed networking and packet buffering applications.

For engineers reviewing the 71V2556SA133BGI8 datasheet, 71V2556SA133BGI8 pinout, 71V2556SA133BGI8 application, or 71V2556SA133BGI8 equivalent, key selection criteria include ZBT timing compliance, TQFP-100 package compatibility, industrial temperature range (–40°C to +85°C), JTAG test support, and burst counter behavior under ADV/LD and LBO control.

Technical Context

This device implements a fully synchronous, clock-edge-triggered architecture with address/data/control registers aligned to the rising CLK edge. Its internal burst counter increments on ADV/LD = HIGH and loads external addresses on ADV/LD = LOW, enabling deterministic linear or interleaved burst sequences selected by the LBO pin.

The ZBT™ architecture eliminates dead cycles between read/write transitions via internally synchronized OE and pipelined output registers. Clock Enable (CEN) halts register updates without affecting output state, while CE1/CE2/CE2 enable depth expansion and precise cycle gating with two-cycle tri-state latency upon deselect.

Key Specifications

Pinout & Package

71V2556SA133BGI8 is packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 1 is located at top-left corner (notch-mark side), with pins numbered counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV18-133BZI and AS7C3256B-133JCIN, the 71V2556SA133BGI8 uniquely delivers 2.5V I/O separation, JTAG testability, and configurable linear/interleaved burst-enabling higher signal integrity, easier validation, and optimized throughput in protocol-aware systems.

Availability

71V2556SA133BGI8 is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, high-speed test equipment, and industrial PLC data logging requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 71V2556SA133BGI8 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 71V2556SA133BGI8 belongs to IDT's ZBT™ SRAM product line, designed specifically for zero-latency bus turnaround in high-throughput packet-switching and real-time signal processing systems.

FAQ

What is the maximum operating frequency of the 71V2556SA133BGI8?

The 71V2556SA133BGI8 is rated for 133 MHz operation, delivering a 7.5 ns clock-to-data access time. This specification is guaranteed over the full industrial temperature range (–40°C to +85°C) and 3.3 V ±5% VDD supply, with 2.5 V VDDQ. Performance is validated using JEDEC-standard AC test conditions with 50 Ω load and defined setup/hold margins.

Does the 71V2556SA133BGI8 support both linear and interleaved burst modes?

Yes, the 71V2556SA133BGI8 supports both linear and interleaved 4-word burst sequences. The LBO (Burst Order) pin selects the mode: tied to VSS for linear (0,1,2,3) and to VDD for interleaved (0,2,1,3). This configuration is sampled at burst initiation and remains active throughout the burst cycle.

What is the function of the ADV/LD pin on the 71V2556SA133BGI8?

The ADV/LD pin on the 71V2556SA133BGI8 serves dual functions: when LOW, it loads a new external address into the internal address register; when HIGH, it advances the internal burst counter. This eliminates external address generation logic during burst reads/writes and ensures deterministic sequence control.

Is JTAG boundary scan supported on the 71V2556SA133BGI8?

Yes, the 71V2556SA133BGI8 includes optional IEEE 1149.1-compliant JTAG boundary scan functionality. Pins TMS, TDI, TCK, TDO, and TRST are assigned to dedicated balls/pins in the BGA variant and are NC (no-connect) in the TQFP version unless explicitly enabled per ordering code - the "SA" suffix confirms JTAG capability in this variant.

How does the ZBT™ architecture eliminate dead cycles in the 71V2556SA133BGI8?

The ZBT™ architecture in the 71V2556SA133BGI8 eliminates dead cycles by synchronizing output enable internally and decoupling read/write transitions from bus turnaround delays. Unlike traditional SRAMs, it allows immediate read-after-write or write-after-read without wait states, achieving continuous data flow at full clock rate.