Renesas 71V3557S80BG

Overview

71V3557S80BG 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 capability. It supports interleaved or 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 network switch fabric memory subsystems.

For engineers reviewing the 71V3557S80BG datasheet, 71V3557S80BG pinout, 71V3557S80BG application, or 71V3557S80BG equivalent, key selection criteria include ZBT™ timing compliance, TQFP-100 package compatibility, 3.3V core/I/O supply tolerance, burst counter behavior under ADV/LD control, and sleep mode (ZZ) support for low-power standby states.

Technical Context

The 71V3557S80BG implements a synchronous dual-register architecture: address/control signals are latched on the rising edge of CLK when CEN is low and chip enables (CE1, CE2, CE2) are asserted; data input is registered while output is flow-through (no output register). Burst sequencing is controlled by LBO and advanced via ADV/LD, enabling deterministic 4-cycle data transfers per address load.

Its ZBT™ feature eliminates dead cycles between read/write transitions by allowing immediate bus direction reversal without wait states. The device integrates a JTAG TAP controller with optional TRST, supporting IEEE 1149.1 boundary scan for production test - all synchronized to CLK except OE (asynchronous) and TRST (optional asynchronous reset).

Key Specifications

Pinout & Package

71V3557S80BG is packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 1 is located at top-left corner (marking dot adjacent), with pins numbered counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV18-100BZI and AS7C3256B-10JIN, the 71V3557S80BG delivers higher bandwidth via 36-bit ZBT™ operation, deterministic burst control, and integrated JTAG - making it uniquely suited for modern high-speed packet-processing architectures requiring zero-wait-state memory access.

Availability

71V3557S80BG is available at Aetrix Electronics and suitable for network packet buffering, telecom switch fabric memory, and industrial PLC data logging requiring stable component supply across extended product lifecycles.

Supply support for 71V3557S80BG 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) is a fabless semiconductor company specializing in timing, memory interface, RF, and power management ICs for communications, computing, and industrial markets.

The 71V3557S80BG belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency, high-throughput memory subsystems in networking and telecom infrastructure where deterministic burst access and bus turnaround elimination are critical.

FAQ

What is the memory organization and density of the 71V3557S80BG?

The 71V3557S80BG is organized as 128K × 36 bits, delivering 4.5 Mbit (4,718,592-bit) total capacity. It supports an alternative 256K × 18-bit configuration via pin strapping, maintaining identical timing and feature set. This dual-configuration flexibility allows system designers to optimize bus width versus depth based on controller interface requirements without changing the 71V3557S80BG footprint or firmware.

Does the 71V3557S80BG support true zero bus turnaround (ZBT™) operation?

Yes, the 71V3557S80BG implements ZBT™ (Zero Bus Turnaround) functionality, eliminating dead cycles between consecutive read and write operations. This is achieved through its synchronous dual-register architecture and flow-through outputs, allowing immediate bus direction reversal on the next clock edge. Verified timing diagrams confirm no wait states are inserted during read-to-write or write-to-read transitions - a key differentiator from standard synchronous SRAMs like the AS7C3256B-10JIN.

What package type and pin count does the 71V3557S80BG use?

The 71V3557S80BG uses a JEDEC-standard 100-pin thin quad flatpack (TQFP) package, measuring 14 mm × 20 mm with 0.5 mm lead pitch. Pin 1 is marked by a dot in the top-left corner, and the pinout includes dedicated address (A0–A17), control (CE1/CE2/CE2, R/W, ADV/LD, LBO, ZZ), data (I/O0–I/O31, I/OP1–I/OP4), and JTAG (TMS/TDI/TCK/TDO/TRST) terminals - fully documented in the IDT DSC-5282 datasheet.

How does the burst counter operate in the 71V3557S80BG?

The 71V3557S80BG's burst counter advances on each rising CLK edge when ADV/LD is high, generating four sequential addresses per initial load. Burst order (linear or interleaved) is selected by the static LBO pin. During burst reads/writes, data transfers occur one cycle after the counter advances - ensuring predictable 4-word sequences without external address generation. The counter wraps automatically after the fourth word, enabling seamless streaming.

Is JTAG boundary scan supported on the 71V3557S80BG, and what signals are required?

Yes, the 71V3557S80BG includes IEEE 1149.1-compliant JTAG boundary scan. Required signals are TMS (Test Mode Select), TDI (Test Data In), TCK (Test Clock), TDO (Test Data Out), and optional TRST (JTAG Reset). All JTAG pins are synchronous to CLK except TRST, which is asynchronous. The TAP controller is fully integrated and functional in both commercial and industrial temperature grades - confirmed in the DSC-5282 datasheet section "Functional Block Diagram" and "Pin Definitions".