Renesas 71V3556SA100BQGI

Overview

71V3556SA100BQGI 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 time, zero bus turnaround architecture, and JEDEC-standard 100-pin TQFP packaging. It serves as a high-bandwidth, low-latency memory buffer in network packet processors and telecom line cards requiring burst pipelined reads/writes.

For engineers reviewing the 71V3556SA100BQGI datasheet, 71V3556SA100BQGI pinout, 71V3556SA100BQGI application, or 71V3556SA100BQGI equivalent, key selection criteria include ZBT™ dead-cycle elimination, 4-word interleaved/linear burst capability, individual byte write control (BW1–BW4), JTAG boundary scan support, and industrial temperature operation (–40°C to +85°C).

Technical Context

The 71V3556SA100BQGI implements a fully synchronous, pipelined architecture where address/control registration occurs on the rising CLK edge, with data output valid two cycles later. Its ZBT™ feature eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions without idle cycles.

It integrates a synchronous burst counter controlled by ADV/LD and LBO pins, supports linear or interleaved 4-word bursts, and includes three chip enables (CE1, CE2, CE2) for depth expansion. The optional IEEE 1149.1 JTAG interface (TMS/TDI/TCK/TDO/TRST) is implemented in SA variants and available in BGA packages.

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 CY7C1362BV33-100BGXI and AS7C33128PFSIG, the 71V3556SA100BQGI uniquely delivers ZBT™ dead-cycle elimination, integrated 4-word burst counter, and JTAG testability in a 100-pin TQFP-making it optimal for new high-performance networking and telecom designs demanding deterministic latency and debug flexibility.

Availability

71V3556SA100BQGI is available at Aetrix Electronics and suitable for telecom infrastructure, industrial networking, and embedded computing applications requiring stable component supply, long-lifecycle support, and industrial-temperature qualification.

Supply support for 71V3556SA100BQGI 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 71V3556SA100BQGI belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency memory subsystems in packet-switched networks, baseband processors, and high-end FPGA-based accelerators.

FAQ

What is the memory organization and total capacity of the 71V3556SA100BQGI?

The 71V3556SA100BQGI is organized as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This configuration supports 36-bit wide data buses common in network processors and DSPs, and is distinct from the 256K × 18 variant offered in the same family. The 71V3556SA100BQGI uses all 17 address lines (A0–A16) to access the full 128K depth.

Does the 71V3556SA100BQGI support JTAG boundary scan, and which pins implement it?

Yes, the 71V3556SA100BQGI supports IEEE 1149.1-compliant JTAG boundary scan as an optional feature. In the 100-pin TQFP package, JTAG signals are assigned to pins NC/TMS, NC/TDI, NC/TCK, NC/TDO, and NC/TRST (pins R5, R6, R7, R8, and R9 per BGA pinout mapping-confirmed via IDT documentation for SA variants). TRST is optional and internally pulled up; if unused, it may be left floating.

How does the ZBT™ feature in the 71V3556SA100BQGI eliminate dead cycles between read and write operations?

The ZBT™ (Zero Bus Turnaround) feature in the 71V3556SA100BQGI removes idle cycles by allowing immediate transition from a write to a read (or vice versa) without bus direction settling time. This is achieved through internal synchronization of OE and directional control, enabling back-to-back operations at full clock rate. The 71V3556SA100BQGI achieves this without external OE timing management-unlike conventional SRAMs that require explicit bus turnaround delays.

What are the burst addressing modes supported by the 71V3556SA100BQGI, and how is selection controlled?

The 71V3556SA100BQGI supports both linear and interleaved 4-word burst sequences, selected via the LBO (Linear Burst Order) pin: LBO = LOW selects linear mode (A0, A1, A2, A3), while LBO = HIGH selects interleaved mode (A0, A2, A1, A3). Burst progression is managed entirely by the internal counter advanced on each rising CLK edge when ADV/LD = HIGH, eliminating external address generation logic.

Can the 71V3556SA100BQGI operate in low-power mode, and how is it activated?

Yes, the 71V3556SA100BQGI supports a synchronous sleep mode activated by driving the ZZ pin HIGH. When asserted, ZZ gates the internal clock and reduces power consumption to its minimum while guaranteeing data retention. This mode is fully compatible with the industrial temperature range (–40°C to +85°C) and requires no additional voltage rails or sequencing-making the 71V3556SA100BQGI suitable for energy-conscious telecom and gateway applications.