Renesas 71V3556S133PFGI8

Overview

71V3556S133PFGI8 from IDT (now Renesas) is a 128K × 36-bit, 4.5 Mbit, 3.3V synchronous ZBT™ SRAM with zero bus turnaround, pipelined outputs, and 4-word burst capability. It operates at 133 MHz (7.5 ns clock-to-data access), supports linear/interleaved burst modes via LBO pin, and features individual byte write enables (BW1–BW4) for precise data control in high-speed memory subsystems such as network packet buffers and cache controllers.

For engineers reviewing the 71V3556S133PFGI8 datasheet, 71V3556S133PFGI8 pinout, 71V3556S133PFGI8 application, or 71V3556S133PFGI8 equivalent, key selection considerations include its ZBT™ architecture eliminating dead cycles between read/write transitions, JEDEC-standard 100-pin TQFP package with industrial temperature support (–40°C to +85°C), and integrated JTAG boundary scan (IEEE 1149.1) for testability in dense PCB layouts.

Technical Context

The 71V3556S133PFGI8 implements a fully synchronous, clock-edge-triggered architecture where address, control, and data registers are sampled on the rising edge of CLK. Its internal burst counter advances on ADV/LD = HIGH, enabling four-cycle burst transfers without external sequencing logic.

ZBT™ operation is achieved through internally synchronized output buffer enable-eliminating OE timing constraints-and dual-phase pipelining: address/control latching occurs on cycle N, while data transfer occurs on cycle N+2. The device supports three chip enables (CE1, CE2, CE2) with two-cycle deselect and optional sleep mode (ZZ pin) for power reduction while retaining data.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV33-133BZI and AS7C33128PFSI-133, the 71V3556S133PFGI8 uniquely delivers ZBT™-enabled zero-gap memory access, integrated burst control, and production-ready JTAG-making it the only option for deterministic, high-throughput, testable SRAM in telecom and industrial control.

Availability

71V3556S133PFGI8 is available at Aetrix Electronics and suitable for network packet buffering, high-speed cache controllers, and industrial real-time controllers requiring stable component supply across extended product lifecycles.

Supply support for 71V3556S133PFGI8 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 71V3556S133PFGI8 belongs to IDT's ZBT™ SRAM product line, designed specifically for zero-latency memory subsystems in high-speed networking, telecom infrastructure, and real-time embedded systems demanding deterministic access and burst efficiency.

FAQ

What does the 'S' suffix in 71V3556S133PFGI8 indicate?

The 'S' denotes the standard version of the IDT71V3556 family-non-JTAG (no TMS/TDI/TDO/TRST pins activated). This distinguishes it from the 'SA' variant, which includes full IEEE 1149.1 boundary scan functionality. The 71V3556S133PFGI8 retains all core ZBT™ SRAM features including burst counter, byte write, and sleep mode, but omits optional JTAG test circuitry.

Does 71V3556S133PFGI8 support both linear and interleaved burst modes?

Yes, the 71V3556S133PFGI8 supports both burst sequences via the LBO (Linear Burst Order) pin. When LBO is driven LOW, the device executes linear bursts (e.g., addresses 0,1,2,3); when HIGH, it performs interleaved bursts (e.g., 0,2,1,3). This static configuration is set at power-up and remains fixed during operation-no runtime switching is supported.

How does the ZBT™ feature eliminate dead cycles in 71V3556S133PFGI8?

The ZBT™ architecture in the 71V3556S133PFGI8 eliminates dead cycles by internally synchronizing output buffer enable-removing the need for external OE timing control-and using pipelined register stages so that the next memory access (read or write) can begin immediately after the previous one completes. This enables true back-to-back transactions at full clock rate without bus turnaround gaps.

What is the function of the ZZ pin on 71V3556S133PFGI8?

The ZZ pin on the 71V3556S133PFGI8 is a synchronous sleep mode input. When asserted HIGH, it gates the internal clock and places the device into its lowest-power state while guaranteeing data retention. The 71V3556S133PFGI8 exits sleep mode synchronously on the next valid CLK edge after ZZ returns LOW, with no reset or initialization sequence required.

Can 71V3556S133PFGI8 be used in place of 71V3556SA133PFGI8?

No-71V3556S133PFGI8 and 71V3556SA133PFGI8 are not pin-compatible replacements. While both share identical memory organization, timing, and core functionality, the 'SA' variant activates JTAG pins (TMS, TDI, TCK, TDO, TRST) that are NC (no-connect) on the 'S' version. Substituting them requires PCB layout changes and firmware validation of JTAG functionality.