Renesas 71V2556SA100BGI

Overview

71V2556SA100BGI from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit (4.5 Mbit) organization, 100 MHz operation (10 ns clock-to-data), pipelined outputs, and zero bus turnaround for seamless read/write transitions in high-speed memory subsystems used in network packet buffers and telecom switching fabrics.

For engineers reviewing the 71V2556SA100BGI datasheet, 71V2556SA100BGI pinout, 71V2556SA100BGI application, or 71V2556SA100BGI equivalent, key selection criteria include burst mode support (linear/interleaved), individual byte write control (BW1–BW4), JTAG boundary scan capability, industrial temperature range (–40°C to +85°C), and TQFP-100 packaging with 2.5V I/O supply.

Technical Context

The 71V2556SA100BGI implements a fully synchronous, clock-edge-triggered architecture with input/output registers aligned to the rising edge of CLK. It integrates an on-chip burst counter controlled by ADV/LD and LBO, enabling four-word bursts without external address sequencing.

Its ZBT™ architecture eliminates dead cycles between read and write operations via internal synchronization of OE and pipelined output enable, while three chip enables (CE1, CE2, CE2) support depth expansion and precise bank control in multi-SRAM systems.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV18-167BZI and AS7C33128P-10TIN, the 71V2556SA100BGI uniquely delivers zero bus turnaround in a synchronous 100 MHz interface with integrated burst counter and industrial-temperature JTAG support-making it optimal for telecom and networking systems prioritizing deterministic latency over peak bandwidth or legacy compatibility.

Availability

71V2556SA100BGI is available at Aetrix Electronics and suitable for network packet buffering, telecom switch fabric memory, baseband processor caching, and industrial real-time controller memory requiring stable component supply and long-term industrial temperature support.

Supply support for 71V2556SA100BGI 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 interface, and RF solutions for communications and computing infrastructure.

The 71V2556SA100BGI belongs to IDT's ZBT™ SRAM product line, designed specifically for high-speed, low-latency memory subsystems in carrier-class networking, telecom switching, and real-time embedded systems demanding deterministic timing and industrial reliability.

FAQ

What is the maximum operating frequency of the 71V2556SA100BGI?

The 71V2556SA100BGI is rated for 100 MHz operation (10 ns clock cycle). Its clock-to-data access time is specified at 3.5 ns, and it supports fully pipelined, synchronous operation with all inputs registered on the rising edge of CLK. This frequency is validated across the full industrial temperature range (–40°C to +85°C) and 3.3V ±5% supply.

Does the 71V2556SA100BGI support burst mode, and how is it configured?

Yes, the 71V2556SA100BGI supports 4-word burst mode using its on-chip burst counter. Burst order-linear or interleaved-is selected via the LBO pin (LBO = VSS for linear, LBO = VDD for interleaved). The ADV/LD pin controls counter behavior: LOW loads an external address, HIGH increments the counter. This eliminates external burst address generation logic.

What is the purpose of the three chip enable pins (CE1, CE2, CE2) on the 71V2556SA100BGI?

The 71V2556SA100BGI uses CE1, CE2, and CE2 to implement hierarchical chip select logic. CE = L requires CE1 = L, CE2 = L, and CE2 = H; any deviation deselects the device. This allows flexible depth expansion in multi-SRAM systems and enables partial bank activation without disrupting ongoing transfers, as pending reads/writes complete before tri-state.

Is JTAG boundary scan supported on the 71V2556SA100BGI, and which pins are used?

Yes, the 71V2556SA100BGI includes optional IEEE 1149.1-compliant JTAG boundary scan. Pins TMS, TDI, TCK, TDO, and TRST (all located on the TQFP-100 package) provide full test access. TRST is optional and may be left floating (internally pulled to VDD); unused JTAG pins default to NC in non-SA variants but are functional in the SA version.

How does the ZBT™ architecture of the 71V2556SA100BGI eliminate bus turnaround cycles?

The 71V2556SA100BGI's ZBT™ architecture eliminates bus turnaround cycles by synchronizing OE internally to CLK and using pipelined output registers. This ensures that a read cycle can immediately follow a write (or vice versa) without requiring bus release, tristate settling, or re-arbitration-reducing effective latency by one full clock cycle per transition and increasing usable bandwidth in burst-heavy workloads.