Renesas 71V3556SA100BQG

Overview

71V3556SA100BQG from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit organization (4.5 Mbit), 100 MHz clock speed, 3.5 ns clock-to-data access, zero bus turnaround architecture, and JEDEC-standard 100-pin TQFP package. It serves as a high-bandwidth, low-latency memory buffer in network packet processors and telecom line cards requiring burst pipelined reads/writes without dead cycles.

For engineers reviewing the 71V3556SA100BQG datasheet, 71V3556SA100BQG pinout, 71V3556SA100BQG application, or 71V3556SA100BQG equivalent, key selection criteria include ZBT™ burst timing compliance, 3.3V I/O voltage tolerance, industrial temperature support (–40°C to +85°C), JTAG IEEE 1149.1 test interface availability, and 4-word linear/interleaved burst mode configuration via LBO pin.

Technical Context

The 71V3556SA100BQG implements a fully pipelined synchronous architecture with positive-edge-triggered address, data, and control registers. Its ZBT™ feature eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions without wait states.

It integrates an on-chip 4-word burst counter, selectable linear or interleaved sequence via static LBO input, and three chip enables (CE1, CE2, CE2) for depth expansion. The device supports individual byte write control (BW1–BW4), asynchronous OE, and optional boundary-scan JTAG (TMS/TDI/TCK/TDO/TRST) compliant with IEEE 1149.1.

Key Specifications

Pinout & Package

71V3556SA100BQG is packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, lead pitch 0.5 mm. Pin 64 supports ZZ (sleep mode) on latest die revision; pins 14, 16, and 66 require ≥VIH but need not be tied directly to VDD.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV18-100BZI and AS7C33128P-10TIN, the 71V3556SA100BQG uniquely delivers ZBT™-enabled deterministic burst timing, industrial temperature support, and integrated JTAG-making it the sole option for carrier-grade, real-time, and test-critical deployments.

Availability

71V3556SA100BQG is available at Aetrix Electronics and suitable for network infrastructure, telecom line cards, and industrial control systems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for 71V3556SA100BQG 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 markets.

The 71V3556SA100BQG belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency, high-throughput memory buffering in packet-switched networks and real-time signal processing systems.

FAQ

What is the memory organization and total capacity of the 71V3556SA100BQG?

The 71V3556SA100BQG is configured as 128K × 36-bit, delivering 4,718,592 bits (4.5 Mbit) of synchronous SRAM. This organization supports 36-bit data paths common in network processors and DSPs, and is distinct from the 256K × 18-bit variant offered in the same family. The device uses a high-performance CMOS process and is optimized for burst-mode operation.

Does the 71V3556SA100BQG support JTAG boundary scan, and which pins are used?

Yes, the 71V3556SA100BQG supports IEEE 1149.1-compliant JTAG boundary scan. Pins TMS, TDI, TCK, TDO, and optional TRST are assigned for this function. These pins are NC in non-SA versions but enabled in the "SA" suffix variant like the 71V3556SA100BQG. TRST is optional and internally pulled up; if unused, it may be left floating.

How does the ZBT™ feature improve system performance in the 71V3556SA100BQG?

The ZBT™ (Zero Bus Turnaround) feature in the 71V3556SA100BQG eliminates dead cycles between consecutive read and write operations. Unlike conventional SRAMs that require bus turnaround time, the 71V3556SA100BQG allows immediate back-to-back access-e.g., a write followed instantly by a read-enabling 100% bus utilization and predictable latency critical for packet buffering and real-time control loops.

What is the role of the ADV/LD and LBO pins in burst operation of the 71V3556SA100BQG?

In the 71V3556SA100BQG, ADV/LD controls burst initiation: sampled low to load a new external address, sampled high to advance the internal 4-word burst counter. LBO selects burst order-low for linear (0,1,2,3), high for interleaved (0,2,1,3). Both signals are synchronous and must remain stable during burst execution to prevent address misalignment or data corruption.

Can the 71V3556SA100BQG operate in low-power mode, and how is it controlled?

Yes, the 71V3556SA100BQG supports low-power sleep mode via the synchronous ZZ pin. When ZZ is driven high, the internal clock is gated and core logic is powered down while retaining memory contents. Power consumption drops significantly, and the device resumes normal operation on the next valid CLK edge after ZZ returns low-no initialization or retraining is required.