Renesas 71V3559S85BG8

Overview

IDT71V3559S85BG8 from Integrated Device Technology is a 3.3V synchronous ZBT™ SRAM organized as 128K x 36 (4.5 Mbit), featuring flow-through outputs, 4-word burst capability (linear or interleaved), and zero bus turnaround for high-speed memory interfacing in networking and telecom data-path applications.

For engineers reviewing the IDT71V3559S85BG8 datasheet, IDT71V3559S85BG8 pinout, IDT71V3559S85BG8 application, or IDT71V3559S85BG8 equivalent, key selection criteria include its 100 MHz clock rate, synchronous burst counter, individual byte write enables (BW1–BW4), JTAG boundary scan support, and JEDEC-standard 100-pin TQFP package with VDD/VDDQ separation.

Technical Context

The IDT71V3559S85BG8 implements a synchronous dual-edge-triggered control architecture where address, R/W, ADV/LD, and byte write signals are registered on the rising CLK edge. Its internal burst counter advances on ADV/LD = HIGH, enabling four consecutive data transfers per address load without dead cycles between read/write transitions.

It integrates flow-through output logic (no output register), asynchronous OE for tri-state control, and a synchronous ZZ sleep mode that gates CLK internally while guaranteeing data retention. The device supports IEEE 1149.1 JTAG boundary scan via dedicated TMS/TDI/TCK/TDO/TRST pins, with TRST optional and internally pulled up.

Key Specifications

Pinout & Package

Package: JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm, 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 CY7C1355KV18-100BZI and AS7C3256A-10JIN, the IDT71V3559S85BG8 uniquely delivers ZBT™ zero-turnaround, integrated burst counter, and industrial-grade JTAG testability in a pin-defined 100-pin TQFP-enabling simpler controller design, lower system latency, and higher production test coverage.

Availability

IDT71V3559S85BG8 is available at Aetrix Electronics and suitable for packet buffering in telecom switches, line card memory in industrial routers, and high-speed test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for IDT71V3559S85BG8 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 real-time interconnect solutions for communications and computing infrastructure.

The IDT71V3559S85BG8 belongs to IDT's ZBT™ SRAM product line, designed specifically for high-speed data-path applications requiring deterministic burst access, zero bus turnaround, and industrial reliability in networking and telecom systems.

FAQ

What is the memory organization and total capacity of the IDT71V3559S85BG8?

The IDT71V3559S85BG8 is organized as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). It supports both 128K × 36 and 256K × 18 configurations via pin-compatible variants, with the IDT71V3559S85BG8 specifically configured for the 128K × 36 mode. This structure provides 36-bit wide data access optimized for high-throughput packet processing applications.

Does the IDT71V3559S85BG8 support burst mode, and how is burst order selected?

Yes, the IDT71V3559S85BG8 supports 4-word synchronous burst mode with selectable linear or interleaved addressing. Burst order is controlled by the LBO (Linear/Interleaved Burst Order) pin: LBO = LOW selects linear burst (A0, A1, A2, A3), while LBO = HIGH selects interleaved burst (A0, A1, A2, A3 in bit-reversed sequence). The burst counter advances automatically on ADV/LD = HIGH, eliminating need for external address sequencing logic.

What is the role of the ZZ pin on the IDT71V3559S85BG8, and does it retain data in sleep mode?

The ZZ pin on the IDT71V3559S85BG8 is a synchronous sleep mode input. When driven HIGH, it gates the internal clock and places the device in its lowest power consumption state. Crucially, data retention is guaranteed during sleep mode - all stored memory contents remain intact without refresh. This feature enables significant power savings in idle periods of telecom line cards and test equipment without compromising data integrity.

How does the IDT71V3559S85BG8 implement zero bus turnaround (ZBT™), and what benefit does it provide?

The IDT71V3559S85BG8 implements ZBT™ by eliminating dead cycles between consecutive read and write operations. Its synchronous architecture allows immediate transition from a read burst to a write burst (or vice versa) without bus idle time, using the same clock domain and shared address/data bus. This enables continuous data streaming in high-speed packet buffers and switch fabrics, increasing effective bandwidth by up to 25% compared to conventional SRAMs requiring turnaround cycles.

Is JTAG boundary scan supported on the IDT71V3559S85BG8, and which pins are used?

Yes, the IDT71V3559S85BG8 includes optional IEEE 1149.1-compliant JTAG boundary scan. It uses five dedicated pins: TMS (Test Mode Select), TDI (Test Data Input), TCK (Test Clock), TDO (Test Data Output), and TRST (optional JTAG reset). TRST is internally pulled up and may be left floating if not used. This capability enables full pin-level controllability and observability for production testing and board-level diagnostics.