Renesas 71V2556S150PFG

Overview

71V2556S150PFG from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit organization (4.5 Mbit), 150 MHz operation (6.7 ns clock cycle), pipelined outputs, and zero-bus-turnaround architecture. It features 2.5V I/O supply, individual byte write control (BW1–BW4), and supports linear/interleaved 4-word burst modes for high-throughput memory subsystems in network packet buffers and telecom line cards.

For engineers reviewing the 71V2556S150PFG datasheet, 71V2556S150PFG pinout, 71V2556S150PFG application, or 71V2556S150PFG equivalent, key selection criteria include ZBT timing compliance, TQFP-100 package compatibility, 3.3V core / 2.5V I/O voltage separation, industrial temperature support (–40°C to +85°C), and JTAG testability (IEEE 1149.1 optional).

Technical Context

The 71V2556S150PFG implements a fully synchronous, clock-edge-triggered architecture with address/data/control registers aligned to the rising edge of CLK. Its internal burst counter enables single-address-initiated 4-word transfers, with LBO selecting linear or interleaved sequence order.

ZBT operation eliminates dead cycles between read/write transitions via internally synchronized OE and pipelined output registers. The device uses three chip enables (CE1, CE2, CE2) for depth expansion and supports sleep mode via ZZ (pin 64, BGA T7) on latest die revisions.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body size, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV18 and AS7C3256A, the 71V2556S150PFG delivers 2× wider data path, ZBT elimination of bus dead cycles, and deterministic 3.5 ns Clk→Q-making it uniquely suitable for high-throughput, low-jitter synchronous memory subsystems.

Availability

71V2556S150PFG is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, industrial PLC data logging, and test equipment pattern memory requiring stable component supply and industrial-temperature reliability.

Supply support for 71V2556S150PFG 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 71V2556S150PFG belongs to IDT's ZBT SRAM product line, designed specifically for zero-latency, high-bandwidth memory subsystems in networking, telecom, and industrial real-time systems demanding deterministic timing and burst efficiency.

FAQ

What is the maximum operating frequency and corresponding clock cycle time for the 71V2556S150PFG?

The 71V2556S150PFG is rated for 150 MHz operation, corresponding to a 6.7 ns clock cycle time. This is confirmed in the Absolute Maximum Ratings and AC Electrical Characteristics sections of the official datasheet. The device achieves this speed while maintaining guaranteed 3.5 ns clock-to-data access time under industrial temperature and voltage conditions.

Does the 71V2556S150PFG support both linear and interleaved burst modes, and how is the selection implemented?

Yes, the 71V2556S150PFG supports both linear and interleaved 4-word burst modes. Selection is controlled by the LBO (Linear/Interleaved Burst Order) pin: tying LBO to VSS selects linear burst, while tying it to VDD selects interleaved burst. This hardware-selectable configuration avoids software overhead and ensures deterministic burst behavior at power-up.

What are the power supply requirements for the 71V2556S150PFG, and are VDD and VDDQ electrically isolated?

The 71V2556S150PFG requires two independent supplies: VDD = 3.3 V ±5% for core logic and VDDQ = 2.5 V ±10% for I/O buffers. These supplies are physically and electrically separate-VDD powers internal registers and control logic, while VDDQ drives the 36-bit I/O bus. This separation minimizes noise coupling and supports mixed-voltage system integration.

Is JTAG boundary scan functionality available on the 71V2556S150PFG, and which pins are used?

JTAG boundary scan is optional on the 71V2556S150PFG and implemented via dedicated pins: TMS, TDI, TCK, TDO, and TRST (all located on the TQFP-100 package). These pins are NC on the base "S" version but functional on the "SA" variant. The interface complies with IEEE 1149.1 and supports board-level test and debug without requiring additional test logic.

How does the ZBTTM (Zero Bus Turnaround) feature improve system performance compared to standard synchronous SRAMs?

The ZBTTM feature in the 71V2556S150PFG eliminates mandatory idle cycles between read and write operations. Unlike conventional SRAMs that require bus turnaround time, the 71V2556S150PFG allows immediate back-to-back read/write transitions-enabling sustained 100% bus utilization at 150 MHz and increasing effective memory bandwidth by up to 30% in mixed-access workloads.