Renesas 71V3557S75BG

Overview

71V3557S75BG from Integrated Device Technology is a 128K × 36-bit (4.5 Mbit), 3.3V synchronous ZBT™ SRAM with flow-through outputs, 100 MHz clock operation (7.5 ns clock-to-data access), and zero bus turnaround architecture. It supports interleaved/linear 4-word burst reads/writes, individual byte write control (BW1–BW4), and JTAG boundary scan (IEEE 1149.1). Used in high-speed packet buffering and cache subsystems of networking ASICs and FPGA-based data path controllers.

For engineers reviewing the 71V3557S75BG datasheet, 71V3557S75BG pinout, 71V3557S75BG application, or 71V3557S75BG equivalent, key selection criteria include ZBT™ timing compliance, TQFP-100 package compatibility, 3.3V I/O and core supply requirements, burst counter behavior under ADV/LD control, and sleep mode (ZZ) support for power-gated systems.

Technical Context

The 71V3557S75BG implements a synchronous dual-edge-triggered address/control register pipeline with flow-through output buffers-eliminating output registers to achieve zero latency between internal read completion and data assertion on I/O pins. Its burst counter advances on ADV/LD = HIGH and loads new addresses on ADV/LD = LOW, with LBO pin selecting linear or interleaved sequence order.

Three chip enables (CE1, CE2 active-low; CE2 active-high) enable depth expansion without external logic, while CEN suspends all synchronous operations without affecting output state. The optional JTAG interface (TMS/TDI/TCK/TDO/TRST) supports IEEE 1149.1 boundary scan testing, and ZZ input gates the internal clock to reduce active current to ≤5 mA in sleep mode.

Key Specifications

Pinout & Package

71V3557S75BG is packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 1 marked with dot; pins arranged in clockwise order from top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1371BV25-7BBXC and AS7C33128P-7TIN, the 71V3557S75BG delivers unique value through integrated burst counter, zero-turnaround timing, JTAG testability, and sleep-mode power reduction - making it optimal for new high-performance, testable, and thermally constrained designs.

Availability

71V3557S75BG is available at Aetrix Electronics and suitable for high-speed packet buffering, network processor caching, FPGA-based data path controllers, and industrial motion control systems requiring stable component supply across extended product lifecycles.

Supply support for 71V3557S75BG 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

Integrated Device Technology (IDT), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor solutions for communications, computing, and industrial markets.

The 71V3557S75BG belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency, high-throughput data buffering in networking infrastructure, telecom equipment, and real-time embedded systems demanding deterministic timing and low power in industrial temperature ranges.

FAQ

What is the memory organization and total capacity of the 71V3557S75BG?

The 71V3557S75BG is organized as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This configuration supports 36-bit data paths common in high-end networking and DSP applications. It is not configurable as 256K × 18 - that variant is implemented in the pin-compatible 71V3559S75BG, not the 71V3557S75BG.

Does the 71V3557S75BG support both linear and interleaved burst modes?

Yes, the 71V3557S75BG supports both burst modes via the LBO (Linear/Interleaved Burst Order) pin. When LBO = LOW, the device executes linear burst sequences (e.g., A0, A1, A2, A3); when LBO = HIGH, it uses interleaved order (e.g., A0, A1, A2, A3 per IEEE 1149.1 definition). This selection is static and must remain stable during operation.

What is the function of the ZZ pin on the 71V3557S75BG?

The ZZ pin on the 71V3557S75BG is a synchronous sleep mode input. When asserted HIGH, it gates the internal clock and reduces active current consumption to ≤5 mA while maintaining full data retention. This feature is essential for power-sensitive applications such as fanless industrial controllers and portable test equipment where thermal management is critical.

Is JTAG boundary scan supported on the 71V3557S75BG, and which pins are used?

Yes, the 71V3557S75BG includes optional IEEE 1149.1-compliant JTAG boundary scan. Pins TMS, TDI, TCK, TDO, and TRST (optional reset) are dedicated to the TAP controller. These signals are multiplexed on pins U16 (TMS), U15 (TDI), U14 (TCK), U13 (TDO), and U12 (TRST) in the TQFP-100 package, enabling board-level interconnect testing and debug visibility.

How does the 71V3557S75BG implement zero bus turnaround (ZBT™)?

The 71V3557S75BG achieves ZBT™ through flow-through outputs and synchronized control logic: read data appears on I/O pins one clock cycle after read initiation, and write data is latched on the same cycle that read data would be driven - eliminating bus idle cycles between alternating read/write operations. This architecture enables true back-to-back burst transfers without turnaround penalties.