Renesas 71V3556SA166BQG

Overview

71V3556SA166BQG from Renesas is a 128K × 36-bit, 4.5 Mbit, 3.3V 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 supports interleaved/linear 4-word burst reads/writes and individual byte write control (BW1–BW4), targeting high-throughput packet buffering in network switches and telecom line cards.

For engineers reviewing the 71V3556SA166BQG datasheet, 71V3556SA166BQG pinout, 71V3556SA166BQG application, or 71V3556SA166BQG equivalent, key selection criteria include ZBT™ timing compliance, TQFP-100 package compatibility, industrial temperature support (–40°C to +85°C), and integrated burst counter functionality for deterministic latency in real-time memory subsystems.

Technical Context

The 71V3556SA166BQG implements a fully synchronous, positive-edge-triggered architecture with registered address, data, and control inputs. Its ZBT™ feature eliminates dead cycles between read/write transitions by overlapping bus turnaround with internal memory access-enabling continuous 166 MHz throughput without external OE management.

It integrates an on-chip burst counter controlled by ADV/LD and LBO pins, supporting both linear and interleaved 4-word sequences. The device includes three chip enables (CE1, CE2, CE2) for depth expansion, asynchronous OE for output tri-state control, and optional IEEE 1149.1 JTAG for boundary scan testing in BGA variants-though the BQG suffix confirms this unit is the 100-pin TQFP package with full JTAG support as specified in SA-series documentation.

Key Specifications

Pinout & Package

71V3556SA166BQG is packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body size, with 0.5 mm lead pitch. Pin 1 is located at top-left corner (marked dot), and pin numbering proceeds counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV18-166BZI and AS7C33128PFSI-166, the 71V3556SA166BQG uniquely combines 128K × 36-bit density, true ZBT™ zero-turnaround operation, and integrated JTAG-making it optimal for latency-critical, testable, and space-constrained telecom and networking applications.

Availability

71V3556SA166BQG is available at Aetrix Electronics and suitable for network switch packet buffering, telecom line card memory, real-time signal processing buffers, and high-speed test equipment requiring stable component supply across extended product lifecycles.

Supply support for 71V3556SA166BQG 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

Renesas Electronics is a global semiconductor leader specializing in microcontrollers, analog, power management, and memory solutions for automotive, industrial, and communications markets.

The 71V3556SA166BQG belongs to Renesas' ZBT™ SRAM product line, engineered specifically for high-throughput, low-latency memory subsystems in networking infrastructure and real-time embedded systems.

FAQ

What does the 'SA' suffix indicate in 71V3556SA166BQG?

The 'SA' suffix denotes the version with integrated IEEE 1149.1 JTAG boundary scan capability. Unlike the base 'S' variant, the 71V3556SA166BQG includes functional TMS, TDI, TCK, TDO, and optional TRST pins-enabling in-system testability and debug visibility without requiring external test fixtures.

Does 71V3556SA166BQG support both linear and interleaved burst modes?

Yes, the 71V3556SA166BQG supports both burst orders via the LBO (Linear/Interleaved Burst Order) pin. When LBO is driven LOW, the device executes linear bursts (A0, A1, A2, A3); when HIGH, it performs interleaved bursts (A0, A2, A1, A3). This selection is static and must remain stable during burst operation.

How does the ZBT™ feature eliminate dead cycles in 71V3556SA166BQG?

The ZBT™ architecture in the 71V3556SA166BQG overlaps bus direction control with memory access timing. Unlike conventional SRAMs that require explicit OE or turnaround cycles, the 71V3556SA166BQG internally manages output enable synchronization-allowing immediate read-after-write or write-after-read transitions at full 166 MHz clock rate without inserted wait states.

What is the function of the ZZ pin on 71V3556SA166BQG?

The ZZ pin on the 71V3556SA166BQG is a synchronous sleep mode input. When asserted HIGH, it gates the internal clock and places the device in its lowest power state while guaranteeing data retention. This feature is essential for power-aware systems like portable test gear or energy-efficient telecom modules.

Can 71V3556SA166BQG operate with only two chip enables active?

Yes-the 71V3556SA166BQG requires CE1 = LOW, CE2 = LOW, and CE2 = HIGH for chip selection. CE2 has inverted polarity relative to CE1 and CE2. If any one of these three conditions fails (e.g., CE2 = LOW), the device enters deselect mode, tri-stating the I/O bus two clock cycles later-enabling flexible memory depth expansion with minimal decode logic.