Renesas 71V3556SA166BGGI

Overview

71V3556SA166BGGI from IDT (now Renesas) is a 128K × 36-bit, 4.5-Mbit synchronous ZBT SRAM with zero bus turnaround architecture, 166 MHz operation (3.5 ns clock-to-data access), 3.3 V core/I/O supply, and industrial temperature range (–40°C to +85°C). It supports pipelined reads/writes, 4-word burst (linear/interleaved), individual byte write control (BW1–BW4), and optional IEEE 1149.1 JTAG boundary scan - deployed in high-speed packet buffering and network switch fabric memory subsystems.

For engineers reviewing the 71V3556SA166BGGI datasheet, 71V3556SA166BGGI pinout, 71V3556SA166BGGI application, or 71V3556SA166BGGI equivalent, key selection considerations include ZBT timing compliance, TQFP/BGA package compatibility, 166 MHz sustained burst throughput, sleep mode (ZZ) support, and JTAG testability for production validation.

Technical Context

The 71V3556SA166BGGI implements a fully synchronous, rising-edge-triggered interface with registered address, data, and control inputs. Its ZBT architecture eliminates dead cycles between read/write transitions via internal burst counter coordination and pipelined output registers - enabling back-to-back memory transactions without bus idle time.

It integrates three chip enables (CE1, CE2, CE2) with two-cycle deselect, asynchronous OE for output tri-state control, and a dedicated ZZ pin for synchronous sleep mode (data retention guaranteed). The device supports both linear and interleaved 4-word burst sequences selected by static LBO input, and includes optional JTAG (TMS/TDI/TCK/TDO/TRST) compliant with IEEE 1149.1.

Key Specifications

Pinout & Package

Packaged in a 119-ball fine-pitch BGA (BGG package), JEDEC standard footprint (12 mm × 12 mm), with 3.3 V core/I/O compatibility and industrial temperature rating. Pin pitch is 0.8 mm; ball composition is Pb-free (RoHS-compliant).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 71V3556SA133BGGI and AS7C3256A-15JIN, the 71V3556SA166BGGI delivers highest sustained bandwidth and lowest latency due to ZBT architecture and 166 MHz operation - critical for real-time packet buffering and switch fabric applications where bus efficiency directly impacts throughput.

Availability

71V3556SA166BGGI is available at Aetrix Electronics and suitable for network packet buffering, high-speed switch fabric memory, and telecom line card memory requiring stable component supply across industrial temperature environments and long product lifecycles.

Supply support for 71V3556SA166BGGI 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 fabless semiconductor company specializing in high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The 71V3556SA166BGGI belongs to IDT's ZBT SRAM product line, designed specifically for zero-bus-turnaround, high-throughput memory subsystems in networking and telecom infrastructure where deterministic latency and burst efficiency are critical.

FAQ

What is the memory organization and total capacity of the 71V3556SA166BGGI?

The 71V3556SA166BGGI is organized as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This configuration supports 36-bit data width with 17 address lines (A0–A16), and is pin-compatible with the 256K × 18-bit variant (71V3558SA166BGGI) via reconfiguration of address and I/O mapping.

Does the 71V3556SA166BGGI support burst operations, and how is burst order controlled?

Yes, the 71V3556SA166BGGI supports 4-word burst operations in either linear or interleaved sequence. Burst order is selected by the static LBO (Linear/Interleaved Burst Order) input: LBO = LOW enables linear addressing (A0, A1, A2, A3), while LBO = HIGH selects interleaved (A0, A2, A1, A3). The internal burst counter advances on each rising CLK edge when ADV/LD is HIGH.

What is the function of the ZZ pin on the 71V3556SA166BGGI, and what power savings does it provide?

ZZ is the synchronous sleep mode input on the 71V3556SA166BGGI. When driven HIGH, it gates the internal clock and reduces dynamic power consumption to its lowest level while guaranteeing data retention. This feature is essential for power-constrained telecom and industrial applications where periodic low-power states are required without data loss.

Is JTAG boundary scan supported on the 71V3556SA166BGGI, and which pins are used?

Yes, the 71V3556SA166BGGI includes optional IEEE 1149.1-compliant JTAG boundary scan. Pins TMS, TDI, TCK, TDO, and optional TRST are assigned to dedicated balls in the BGG119 package. TRST is not required, as automatic JTAG reset occurs at power-up and via TMS/TCK sequences per IEEE 1149.1.

How does the ZBT™ architecture in the 71V3556SA166BGGI eliminate bus turnaround dead cycles?

The ZBT™ architecture in the 71V3556SA166BGGI eliminates bus turnaround dead cycles by using an internal burst counter and pipelined output registers that allow immediate transition from write to read (or vice versa) without waiting for bus release/reacquisition. This is achieved through synchronized control of ADV/LD, R/W, and CE signals - enabling back-to-back transactions at full 166 MHz clock rate.