Renesas 71V2556S100PFGI8

Overview

71V2556S100PFGI8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit (4.5 Mbit) organization, 166 MHz operation (3.5 ns clock-to-data access), pipelined outputs, and zero-bus-turnaround architecture. It supports 4-word linear/interleaved burst reads/writes, individual byte write control (BW1–BW4), and operates across industrial temperature (–40°C to +85°C). Used in high-speed packet buffering and network switch fabric memory subsystems.

For engineers reviewing the 71V2556S100PFGI8 datasheet, 71V2556S100PFGI8 pinout, 71V2556S100PFGI8 application, or 71V2556S100PFGI8 equivalent, key selection criteria include ZBT timing compliance, TQFP-100 package compatibility, 2.5V I/O voltage support, burst counter behavior under ADV/LD control, and industrial-grade thermal performance.

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 enables automatic 4-word sequence generation upon ADV/LD assertion, eliminating external address sequencing logic.

The ZBT™ architecture eliminates dead cycles between read/write transitions by overlapping bus turnaround with data transfer - enabled via dedicated R/W pin and internally synchronized OE. Output enable is asynchronous but all other signals are strictly synchronous to CLK.

Key Specifications

Pinout & Package

Packaged in JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 64 supports ZZ (sleep mode) on latest die revision; pins 14/16/66 tolerate VIH ≥ VDD without direct VDD connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV18-167BZI and AS7C33128P-10BIN, the 71V2556S100PFGI8 delivers superior throughput via ZBT™ and pipelined burst - critical for packet-forwarding applications - while maintaining TQFP-100 footprint compatibility absent in the Cypress part and offering synchronous determinism absent in the Alliance part.

Availability

71V2556S100PFGI8 is available at Aetrix Electronics and suitable for network switch fabric buffering, telecom line card packet memory, and industrial PLC data logging requiring stable component supply, long-term lifecycle support, and industrial temperature qualification.

Supply support for 71V2556S100PFGI8 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 fabless semiconductor company specializing in high-performance timing, memory, and interface solutions for communications and computing infrastructure.

The 71V2556S100PFGI8 belongs to IDT's ZBT™ SRAM product line, designed specifically for high-speed networking equipment requiring zero-bus-turnaround, burst-mode operation, and deterministic synchronous timing in packet-switched systems.

FAQ

What is the maximum operating frequency of the 71V2556S100PFGI8?

The 71V2556S100PFGI8 supports a maximum clock frequency of 166 MHz, corresponding to a 6 ns cycle time. This is validated across the full industrial temperature range (–40°C to +85°C) and 3.3 V ±5 % supply, with 3.5 ns clock-to-data access time measured under standard AC test conditions (VDDQ = 2.5 V).

Does the 71V2556S100PFGI8 support burst read and write operations?

Yes, the 71V2556S100PFGI8 supports 4-word burst operations for both reads and writes. The burst sequence order (linear or interleaved) is selected via the LBO pin, and the internal burst counter is advanced using the ADV/LD signal - enabling efficient sequential access without external address generation.

What package type and pin count does the 71V2556S100PFGI8 use?

The 71V2556S100PFGI8 is packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP) with 0.5 mm pitch and 14 mm × 20 mm body size. Pin 64 supports ZZ (sleep mode) on the latest die revision, and pins 14, 16, and 66 may be left unconnected if input voltage meets VIH requirements.

How does the ZBT™ architecture improve system performance in the 71V2556S100PFGI8?

The ZBT™ (Zero Bus Turnaround) architecture in the 71V2556S100PFGI8 eliminates dead cycles between read and write operations by overlapping bus direction control with data transfer. This allows back-to-back read/write bursts without insertion of idle cycles - increasing effective bus utilization by up to 25 % in high-throughput packet buffering applications.

Is the 71V2556S100PFGI8 compatible with 2.5 V logic interfaces?

Yes, the 71V2556S100PFGI8 uses a split-rail supply: VDD = 3.3 V ±5 % for core logic and VDDQ = 2.5 V ±5 % for all I/O pins (I/O[0:31] and I/OP[1:4]). This ensures full compatibility with 2.5 V LVTTL and LVCMOS logic families while maintaining noise isolation between core and I/O domains.