Renesas 71V3556SA133BQI8

Overview

71V3556SA133BQI8 from IDT (now Renesas) is a 3.3V synchronous ZBT SRAM with 128K × 36-bit organization (4.5 Mbit), 133 MHz clock speed, 3.5 ns clock-to-data access, zero bus turnaround architecture, and JEDEC-standard 100-pin TQFP packaging. It enables high-throughput memory buffering in network packet processors and telecom line cards where write-read transition latency must be eliminated.

For engineers reviewing the 71V3556SA133BQI8 datasheet, 71V3556SA133BQI8 pinout, 71V3556SA133BQI8 application, or 71V3556SA133BQI8 equivalent, key selection criteria include ZBT timing compliance, 3.3V I/O voltage tolerance, industrial temperature range (–40°C to +85°C), burst counter support, and JTAG boundary-scan capability for system-level testability.

Technical Context

The 71V3556SA133BQI8 implements a fully pipelined synchronous interface with positive-edge-triggered address, data, and control registers. Its ZBT architecture eliminates dead cycles between read and write operations by overlapping bus turnaround with internal memory access.

It integrates an on-chip 4-word burst counter with linear/interleaved mode selectable via LBO, individual byte write enables (BW1–BW4), three chip enables (CE1, CE2, CE2) for depth expansion, and optional IEEE 1149.1-compliant JTAG for boundary scan - all operating at 3.3V core and I/O supply.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch, 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 CY7C1356BV133BZC and AS7C33128PFSI-133, the 71V3556SA133BQI8 delivers unique ZBT timing, integrated burst counter, and IEEE 1149.1 JTAG - making it the sole option for high-efficiency, testable, industrial-grade 36-bit synchronous buffering.

Availability

71V3556SA133BQI8 is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, baseband processor cache, and industrial PLC data logging requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 71V3556SA133BQI8 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 markets.

The 71V3556SA133BQI8 belongs to IDT's ZBT SRAM product line, engineered specifically for zero-latency bus turnaround in high-speed packet-processing and telecom infrastructure applications.

FAQ

What is the memory configuration and total capacity of the 71V3556SA133BQI8?

The 71V3556SA133BQI8 is configured as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This organization supports 32-bit data paths plus 4-bit parity or ECC in mission-critical systems, and is distinct from the 256K × 18 variant offered in the same family.

Does the 71V3556SA133BQI8 support JTAG boundary-scan, and which pins are used?

Yes, the 71V3556SA133BQI8 supports IEEE 1149.1-compliant JTAG boundary-scan. Pins TMS, TDI, TCK, TDO, and optional TRST (pin 64 in TQFP, though TRST is BGA-only per documentation) implement the test interface. The "SA" suffix explicitly denotes JTAG-enabled versions.

How does the ZBT™ feature improve system performance compared to standard synchronous SRAMs?

The ZBT™ feature in the 71V3556SA133BQI8 eliminates dead cycles between read and write operations by overlapping bus direction changes with internal memory access. Unlike conventional SRAMs that require one idle cycle for bus turnaround, the 71V3556SA133BQI8 sustains continuous 133 MT/s throughput with deterministic timing.

What is the function of the ADV/LD and LBO pins on the 71V3556SA133BQI8?

ADV/LD controls the burst counter: low loads a new external address, high advances the internal counter. LBO selects burst order - low enables linear sequence (0,1,2,3), high enables interleaved (0,2,1,3). Both are synchronous inputs critical for burst-mode operation in packet buffering applications.

Is the 71V3556SA133BQI8 rated for industrial temperature operation, and what is its supply voltage tolerance?

Yes, the 71V3556SA133BQI8 is rated for industrial temperature operation from –40°C to +85°C. Its supply voltage tolerance is 3.3 V ±5% for both VDD (core) and VDDQ (I/O), ensuring robust interoperability with standard 3.3V logic families without external regulation beyond nominal spec.