Renesas 71V3556SA100BGI8

Overview

71V3556SA100BGI8 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 100 MHz (10 ns clock period), delivers 3.5 ns clock-to-data access, supports linear/interleaved burst via LBO pin, and features individual byte write enables (BW1–BW4) for precise memory control in high-speed networking and packet buffering applications.

For engineers reviewing the 71V3556SA100BGI8 datasheet, 71V3556SA100BGI8 pinout, 71V3556SA100BGI8 application, or 71V3556SA100BGI8 equivalent, key selection criteria 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), JTAG-compliant boundary scan (IEEE 1149.1), and synchronous 3.3V core/I/O supply compliance.

Technical Context

The 71V3556SA100BGI8 implements a fully pipelined synchronous interface where address, control, and data registers are triggered on the positive clock edge. Its ZBT™ architecture eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions without idle cycles - critical for backplane and switch fabric memory subsystems.

It integrates an on-chip 4-word burst counter controlled by ADV/LD and LBO pins, supporting both linear and interleaved addressing sequences. The device includes three chip enables (CE1, CE2, CE2) for depth expansion, asynchronous OE for output tri-state control, and optional IEEE 1149.1 JTAG boundary scan for testability - all within a single 3.3V power domain for VDD (core) and VDDQ (I/O).

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 input without direct VDD connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV18-100AXC and AS7C33128PFS-10BIN, the 71V3556SA100BGI8 uniquely delivers 36-bit width, ZBT™ zero-turnaround, and integrated JTAG - making it optimal for high-throughput, testable, and future-proof telecom and industrial memory subsystems.

Availability

71V3556SA100BGI8 is available at Aetrix Electronics and suitable for high-speed packet buffering, network switch fabric memory, telecom line card memory, and industrial real-time controller cache applications requiring stable component supply across extended product lifecycles.

Supply support for 71V3556SA100BGI8 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 71V3556SA100BGI8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency memory subsystems in packet-switched networks, base station equipment, and real-time control systems demanding deterministic timing and burst efficiency.

FAQ

What is the memory configuration and total capacity of the 71V3556SA100BGI8?

The 71V3556SA100BGI8 is configured as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This organization supports a 36-bit parallel data bus, aligning with common 32-bit + 4-bit parity or 4-byte aligned architectures used in high-speed networking ASICs and FPGAs. Its density and width make it ideal for packet buffering and descriptor table storage.

Does the 71V3556SA100BGI8 support burst operations, and how is burst order controlled?

Yes, the 71V3556SA100BGI8 supports 4-word burst operations using an on-chip counter. Burst order is selected via the LBO (Linear/Interleaved Burst Order) pin: LBO = low enables linear addressing (A0, A1, A2, A3), while LBO = high selects interleaved order (A0, A2, A1, A3). The ADV/LD pin controls whether the counter loads a new address (low) or advances (high), enabling flexible burst initiation and chaining.

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

The ZBT™ (Zero Bus Turnaround) feature in the 71V3556SA100BGI8 eliminates idle cycles between consecutive read and write operations - unlike conventional SRAMs that require turnaround time. This allows immediate back-to-back read-after-write or write-after-read transactions, increasing effective bandwidth by up to 25% in mixed-access workloads typical of switch fabric and packet buffer applications.

What are the power supply requirements for the 71V3556SA100BGI8, and are VDD and VDDQ independent?

The 71V3556SA100BGI8 requires two 3.3V supplies: VDD (core logic, 3.3 V ±5%) and VDDQ (I/O drivers, 3.3 V ±5%). Though nominally identical, they are physically separate pins and may be decoupled independently to minimize noise coupling between core logic and I/O switching transients - a key design consideration for signal integrity in high-speed memory buses.

Is JTAG boundary scan supported on the 71V3556SA100BGI8, and which package types include it?

Yes, the 71V3556SA100BGI8 supports IEEE 1149.1-compliant JTAG boundary scan. However, JTAG pins (TMS, TDI, TCK, TDO, TRST) are only available in BGA packages (119-ball and 165-fBGA); the 100-pin TQFP variant (like the 71V3556SA100BGI8) does not include these pins. The "SA" suffix denotes JTAG capability in BGA versions, but the TQFP version retains full functional compatibility without test access.