Renesas 71V3556SA166BGG8

Overview

71V3556SA166BGG8 from IDT (now Renesas) is a 3.3V, 128K × 36-bit synchronous ZBT™ SRAM with zero bus turnaround, 166 MHz operation, 3.5 ns clock-to-data access, pipelined outputs, and JTAG boundary scan (IEEE 1149.1). 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 71V3556SA166BGG8 datasheet, 71V3556SA166BGG8 pinout, 71V3556SA166BGG8 application, or 71V3556SA166BGG8 equivalent, key selection criteria include burst mode support (linear/interleaved), individual byte write control (BW1–BW4), three chip enables for depth expansion, sleep mode (ZZ), and industrial temperature range (–40°C to +85°C) compliance.

Technical Context

The 71V3556SA166BGG8 implements a fully synchronous, rising-edge-triggered architecture with registered address, data, and control inputs. Its ZBT™ feature eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions via internal burst counter and ADV/LD-controlled address sequencing.

It integrates pipelined input/output registers, an on-chip 4-word burst counter selectable via LBO, asynchronous OE for output tri-state control, and optional IEEE 1149.1 JTAG test interface with TMS/TDI/TCK/TDO/TRST pins - all operating at 3.3V core (VDD) and I/O (VDDQ) supplies with ±5% tolerance.

Key Specifications

Pinout & Package

Packaged in a 119-ball fine-pitch BGA (BGG119), JEDEC standard footprint (12 mm × 12 mm), RoHS-compliant, green-part qualified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1371DV33-166AXC and AS7C33128P-166JCIN, the 71V3556SA166BGG8 uniquely delivers integrated JTAG testability, true zero-turnaround operation, and industrial-grade sleep mode - making it the sole choice for telecom infrastructure requiring production test coverage and deterministic real-time performance.

Availability

71V3556SA166BGG8 is available at Aetrix Electronics and suitable for network packet buffering, telecom line card caching, baseband processor memory, and radar signal processing applications requiring stable component supply across extended product lifecycles.

Supply support for 71V3556SA166BGG8 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 71V3556SA166BGG8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency, burst-oriented memory subsystems in carrier-class networking and wireless infrastructure equipment.

FAQ

What is the memory organization and speed grade of the 71V3556SA166BGG8?

The 71V3556SA166BGG8 is a 128K × 36-bit (4.5 Mbit), 166 MHz synchronous SRAM with 3.5 ns clock-to-data access time. It operates at 3.3V core and I/O supplies and supports both linear and interleaved 4-word burst modes. This configuration targets high-bandwidth, low-latency buffering in telecom and networking ASIC/FPGA interfaces.

Does the 71V3556SA166BGG8 support JTAG boundary scan, and which pins are used?

Yes, the 71V3556SA166BGG8 supports IEEE 1149.1 JTAG boundary scan. The dedicated pins are TMS (Test Mode Select), TDI (Test Data Input), TCK (Test Clock), TDO (Test Data Output), and optional TRST (JTAG Reset). These are assigned to specific BGA balls per the BG119 pinout and are functional only in the "SA" version (as indicated by the "SA" suffix in the part number).

How does the ZBT™ feature eliminate bus turnaround dead cycles in the 71V3556SA166BGG8?

The 71V3556SA166BGG8 achieves zero bus turnaround by decoupling address/control registration from data transfer timing. Address and control signals (R/W, ADV/LD, BWx) are latched on one clock edge, and associated read/write data appears exactly two clocks later - enabling immediate back-to-back reads and writes without idle cycles. This is enforced by the synchronous ADV/LD logic and internal burst counter.

What is the function of the ZZ pin on the 71V3556SA166BGG8, and how does it affect power consumption?

The ZZ pin on the 71V3556SA166BGG8 is a synchronous sleep mode input. When driven high, it gates the internal clock and places the device in its lowest power state while guaranteeing data retention. In this mode, dynamic power drops significantly, and the device remains responsive to wake-up events (e.g., CE assertion), making it ideal for power-constrained telecom modules.

Can the 71V3556SA166BGG8 operate in both 128K × 36 and 256K × 18 configurations, and how is this selected?

No - the 71V3556SA166BGG8 is fixed at 128K × 36 organization. The 256K × 18 variant is the pin-compatible 71V3558SA166BGG8. Configuration is determined by the base part number (71V3556S vs 71V3558S); no mode pins or straps exist to switch between them. Both share identical timing, packaging, and feature sets except for address/data width mapping.