Renesas 71V3559S80BQ

Overview

71V3559S80BQ from Integrated Device Technology is a 3.3V synchronous ZBT™ SRAM organized as 256K x 18 (4.5 Mbit), featuring flow-through outputs, 4-word burst capability (linear or interleaved), and zero bus turnaround architecture. It operates at 100 MHz with 7.5 ns clock-to-data access, supports individual byte write control (BW1–BW4), and includes JTAG boundary scan (IEEE 1149.1) for system-level test in high-speed networking and packet buffering applications.

For engineers reviewing the 71V3559S80BQ datasheet, 71V3559S80BQ pinout, 71V3559S80BQ application, or 71V3559S80BQ equivalent, this device is selected for low-latency memory subsystems requiring deterministic burst read/write timing, asynchronous output enable (OE), and synchronous chip enable logic with three independent CE inputs for depth expansion.

Technical Context

The 71V3559S80BQ implements a synchronous dual-edge-triggered interface where address, control, and data-in are registered on the rising edge of CLK, while outputs are flow-through (no output register). Its internal burst counter advances on ADV/LD = HIGH, with burst order selected statically via LBO pin - linear when LBO = LOW, interleaved when LBO = HIGH.

It features three chip enables (CE1, CE2 active-low; CE2 active-high), Clock Enable (CEN) to suspend operation without affecting internal state, and ZZ sleep mode for reduced power with guaranteed data retention. All I/Os are 3.3V-compatible with VDDQ separate from core VDD, and it supports optional JTAG via TMS/TDI/TCK/TDO/TRST pins.

Key Specifications

Pinout & Package

71V3559S80BQ is packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, with 0.5 mm pitch. Pin 64 supports ZZ (sleep mode) on latest die revisions; pins 83 and 84 are reserved for future density extensions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV18-167BZI and AS7C3256A-10JIN, the 71V3559S80BQ uniquely combines industrial temperature support, integrated burst counter with selectable order, JTAG testability, and zero bus turnaround-making it optimal for upgradeable, testable, and latency-critical embedded memory subsystems.

Availability

71V3559S80BQ is available at Aetrix Electronics and suitable for high-speed packet buffering, network switch fabric memory, and industrial PLC data logging requiring stable component supply across extended product lifecycles.

Supply support for 71V3559S80BQ 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, specializes in high-performance timing, memory interface, and RF solutions for communications and computing infrastructure.

The 71V3559S80BQ belongs to IDT's ZBT™ SRAM family, engineered specifically for zero-latency memory subsystems in networking ASICs, switch fabrics, and real-time embedded systems demanding deterministic burst behavior.

FAQ

What is the memory organization and total capacity of the 71V3559S80BQ?

The 71V3559S80BQ is organized as 256K × 18, delivering 4,718,592 bits (4.5 Mbit) of synchronous SRAM. This configuration supports 18-bit data width with 256K addressable words, optimized for systems requiring balanced depth and width-such as packet buffer descriptors or FPGA co-processor memory interfaces. The 71V3559S80BQ does not support 128K × 36 mode; that variant is implemented in the 71V3557S80BQ.

Does the 71V3559S80BQ support both linear and interleaved burst sequences?

Yes, the 71V3559S80BQ supports both linear and interleaved 4-word burst sequences, selected by the static LBO (Linear/Interleaved Burst Order) pin: LBO = LOW enables linear order (A0, A1, A2, A3), while LBO = HIGH enables interleaved order (A0, A2, A1, A3). This flexibility allows alignment with specific ASIC or FPGA memory controller addressing schemes without software overhead. The 71V3559S80BQ requires LBO to remain stable during burst execution.

How does the zero bus turnaround (ZBT™) feature function in the 71V3559S80BQ?

The ZBT™ feature in the 71V3559S80BQ eliminates idle cycles between consecutive read and write operations by allowing immediate direction reversal on the data bus. Unlike conventional SRAMs requiring OE deassertion and bus turnaround delay, the 71V3559S80BQ uses internal flow-through outputs and synchronous control to enable back-to-back bursts-e.g., a burst read followed immediately by a burst write-without inserting dead cycles. This behavior is intrinsic to the 71V3559S80BQ's architecture and requires no external logic.

What is the role of the ADV/LD pin in the 71V3559S80BQ?

The ADV/LD pin in the 71V3559S80BQ serves a dual function: when sampled LOW at the rising CLK edge, it loads a new external address into the internal address register; when sampled HIGH, it advances the internal burst counter to generate the next sequential address. This single pin eliminates the need for separate address latch and burst increment signals, simplifying timing and reducing control lines. Its behavior is fundamental to the 71V3559S80BQ's burst efficiency and deterministic access pattern.

Is JTAG boundary scan supported on the 71V3559S80BQ, and how is it implemented?

Yes, the 71V3559S80BQ includes optional IEEE 1149.1-compliant JTAG boundary scan, implemented via dedicated pins TMS, TDI, TCK, TDO, and optional TRST. These pins are multiplexed with NC functions in the "S" version and fully enabled in the "SA" variant-but the 71V3559S80BQ datasheet confirms JTAG functionality is present and functional. Internal pull-ups on TMS, TDI, and TCK ensure safe default states, and TRST may be left floating if unused. This capability enables in-system test and interconnect verification without modifying the 71V3559S80BQ's primary memory interface.