Renesas 71V3556SA166BGG

Overview

71V3556SA166BGG 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, pipelined outputs, and JTAG boundary scan support. It serves as high-speed buffer/cache memory in network packet processors and telecom line cards requiring deterministic read/write interleaving without dead cycles.

For engineers reviewing the 71V3556SA166BGG datasheet, 71V3556SA166BGG pinout, 71V3556SA166BGG application, or 71V3556SA166BGG equivalent, key selection criteria include burst mode timing (linear/interleaved), byte-write granularity (BW1–BW4), industrial temperature support (–40°C to +85°C), and BGA package compatibility with JEDEC-standard 119-ball grid array layout.

Technical Context

The 71V3556SA166BGG implements a fully synchronous, positive-edge-triggered pipeline: address/control registers sample on CLK rising edge with ADV/LD low for load cycles, and data transfers occur two clocks later. Its ZBT architecture eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions without idle cycles.

It integrates an on-chip 4-word burst counter controlled by LBO (linear/interleaved), ADV/LD (load/advance), and R/W - all synchronized to CLK. Optional IEEE 1149.1 JTAG (TMS/TDI/TCK/TDO/TRST) supports boundary scan testing in BGA packages, with TRST available as asynchronous reset.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 119-ball fine-pitch ball grid array (BGA), designated BGG119 per IDT documentation. Pin pitch is 1.0 mm; body size is 12 mm × 12 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 CY7C1356BV166BZC and AS7C3256A-166BIN, the 71V3556SA166BGG uniquely delivers integrated JTAG testability, true ZBT operation for uninterrupted bus utilization, and hardware-configurable burst sequencing - critical for next-generation telecom and industrial real-time systems.

Availability

71V3556SA166BGG is available at Aetrix Electronics and suitable for network infrastructure, telecom line cards, and industrial PLCs requiring stable component supply with long-term lifecycle assurance.

Supply support for 71V3556SA166BGG 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 and computing markets.

The 71V3556SA166BGG belongs to IDT's ZBT SRAM product line, engineered specifically for zero-latency bus turnaround in high-throughput packet processing and real-time control applications.

FAQ

What is the memory organization and access speed of the 71V3556SA166BGG?

The 71V3556SA166BGG is a 128K × 36-bit (4.5 Mbit) synchronous SRAM operating at up to 166 MHz, delivering a clock-to-data access time of 3.5 ns. It supports both linear and interleaved 4-word burst modes, and its ZBT architecture ensures zero dead cycles between read and write operations - essential for deterministic real-time buffering in networking equipment.

Does the 71V3556SA166BGG support JTAG boundary scan, and which pins are used?

Yes, the 71V3556SA166BGG supports IEEE 1149.1-compliant JTAG boundary scan. The dedicated pins are TMS, TDI, TCK, TDO, and optional TRST - all located on the BGG119 package. TRST is asynchronous and available only in BGA variants; it resets the TAP controller but is not required, as automatic reset occurs at power-up.

How does the burst counter and LBO pin function in the 71V3556SA166BGG?

The 71V3556SA166BGG contains an on-chip 4-word burst counter controlled by ADV/LD and LBO. When ADV/LD = HIGH, the counter increments; when ADV/LD = LOW, a new external address loads. LBO selects burst order: LOW enables linear (0,1,2,3), HIGH enables interleaved (0,2,3,1). LBO is static and must not change during operation to avoid undefined burst behavior.

What are the voltage and temperature specifications for the 71V3556SA166BGG?

The 71V3556SA166BGG operates with VDD = 3.3 V ±5% (core) and VDDQ = 3.3 V ±5% (I/O), over an industrial temperature range of –40°C to +85°C. Absolute maximum ratings include –0.5 V to +4.6 V on terminals, and power dissipation is rated at 2.0 W. These specs ensure robust operation in base stations, industrial controllers, and other thermally demanding environments.

Can the 71V3556SA166BGG perform partial writes, and how is that controlled?

Yes, the 71V3556SA166BGG supports individual byte writes using four active-low enables: BW1–BW4. Each controls a 9-bit byte (I/O[0:7]+I/OP1 through I/O[24:31]+I/OP4). During a write cycle, only bytes with BWx = LOW are updated; others retain prior data. This eliminates need for external byte-lane gating logic and simplifies mixed-format data handling in applications like PLC logging.