Renesas 71V3558SA166BQGI

Overview

71V3558SA166BQGI from IDT (now Renesas) is a 3.3V synchronous ZBT SRAM with 128K × 36-bit organization, 166 MHz operation, 3.5 ns clock-to-data access, zero bus turnaround architecture, and pipelined outputs. It serves as high-speed buffer/cache memory in network switches, telecom line cards, and packet processing engines requiring deterministic latency and burst throughput.

For engineers reviewing the 71V3558SA166BQGI datasheet, 71V3558SA166BQGI pinout, 71V3558SA166BQGI application, or 71V3558SA166BQGI equivalent, key selection criteria include ZBT timing compliance, 4-word burst mode (linear/interleaved), individual byte write control (BW1–BW4), JTAG IEEE 1149.1 support, and industrial temperature range (–40°C to +85°C) in 165-ball fine-pitch BGA packaging.

Technical Context

The 71V3558SA166BQGI implements a fully synchronous, positive-edge-triggered architecture with registered address, data, and control inputs. Its internal burst counter advances on ADV/LD = HIGH, enabling four-cycle data transfers per address load, with LBO selecting linear or interleaved sequence.

ZBT operation eliminates dead cycles between read/write transitions via synchronized output buffer enable and dual-phase chip enable logic (CE1, CE2, CE2). The device supports pipelined reads/writes with two-cycle latency from address/control registration to data valid, and includes optional boundary-scan JTAG for production testability.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 165-ball fine-pitch ball grid array (fBGA), BQ165 footprint, with 1.0 mm ball pitch and 13 mm × 13 mm body size. Pinout validated per IDT document 5281 tbl 25 (128K×36 fBGA configuration).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1372KV18-167BZI and AS7C33128P-166BIN, the 71V3558SA166BQGI uniquely delivers ZBT timing, integrated burst counter, four-byte write control, and industrial-temperature JTAG support in a single 165-ball fBGA package-enabling higher system-level throughput and reduced board complexity.

Availability

71V3558SA166BQGI is available at Aetrix Electronics and suitable for network packet buffering, telecom line card caching, industrial PLC data logging, and avionics data acquisition requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 71V3558SA166BQGI 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 71V3558SA166BQGI belongs to IDT's ZBT SRAM product line, engineered specifically for zero-latency bus turnaround in high-speed packet processing, switching, and real-time control applications demanding deterministic timing and burst efficiency.

FAQ

What is the memory organization and total capacity of the 71V3558SA166BQGI?

The 71V3558SA166BQGI is configured as 128K × 36-bit, delivering 4,718,592 bits (4.5 Mbit) of synchronous SRAM. This organization supports direct interface to 36-bit data buses and enables efficient depth expansion using its three chip enable inputs (CE1, CE2, CE2) without external decoding logic.

Does the 71V3558SA166BQGI support burst read and write operations, and how is burst order controlled?

Yes, the 71V3558SA166BQGI supports 4-word burst operations in both read and write modes. Burst order is selected via the LBO (Linear/Interleaved Burst Order) pin: LBO = LOW configures linear addressing (A0, A1, A2, A3), while LBO = HIGH selects interleaved (A0, A2, A1, A3). The internal burst counter advances on ADV/LD = HIGH.

What is the function of the ZZ (Sleep Mode) pin on the 71V3558SA166BQGI, and what power savings does it provide?

The ZZ pin on the 71V3558SA166BQGI is a synchronous sleep mode input. When driven HIGH, it gates the internal clock and reduces power consumption to its lowest level while guaranteeing data retention. This feature is critical for power-constrained industrial and avionics applications where periodic low-power states are required without data loss.

How does the ZBT™ (Zero Bus Turnaround) feature improve system performance in the 71V3558SA166BQGI?

ZBT™ eliminates dead cycles between consecutive read and write operations by synchronizing output buffer enable and using pipelined control logic. In the 71V3558SA166BQGI, this enables immediate bus turnaround-e.g., a write cycle can be followed directly by a read cycle without idle clocks-maximizing bandwidth utilization in packet-forwarding engines and real-time buffers.

Is JTAG boundary-scan supported on the 71V3558SA166BQGI, and which pins are used?

Yes, the 71V3558SA166BQGI includes optional IEEE 1149.1-compliant JTAG boundary-scan. Pins TMS, TDI, TCK, TDO, and optional TRST are dedicated to this function and are assigned to specific balls in the BQ165 fBGA package (per IDT doc 5281 tbl 25). TRST is internally pulled up and may be left floating if unused.