Renesas 71V3556SA150BG8

Overview

71V3556SA150BG8 from IDT (now Renesas) is a 128K × 36-bit, 4.5 Mbit, 3.3V synchronous ZBT™ SRAM with zero bus turnaround, pipelined outputs, and 150 MHz operation (6.67 ns clock period). It supports interleaved/linear 4-word burst, individual byte write control (BW1–BW4), and JTAG boundary scan (IEEE 1149.1). Used in high-speed networking buffers and packet-switching ASIC/FPGA interfaces.

For engineers reviewing the 71V3556SA150BG8 datasheet, 71V3556SA150BG8 pinout, 71V3556SA150BG8 application, or 71V3556SA150BG8 equivalent, key selection criteria include ZBT™ timing compliance, 100-pin TQFP package compatibility, industrial temperature support (–40°C to +85°C), and JTAG-enabled testability for production validation.

Technical Context

The 71V3556SA150BG8 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.

It integrates a 4-word burst counter controlled by ADV/LD and LBO, supports pipelined output enable (OE asynchronous but internally synchronized), and includes three chip enables (CE1, CE2, CE2) for depth expansion. The SA suffix confirms IEEE 1149.1 JTAG support with TMS/TDI/TCK/TDO/TRST pins.

Key Specifications

Pinout & Package

Packaged in JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 64 supports ZZ (sleep mode) on latest die revision; pins 14/16/66 tolerate VIH-level voltage without direct VDD connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-167AXC and AS7C31026B-15JCIN, the 71V3556SA150BG8 uniquely delivers ZBT™ timing, JTAG testability, industrial temperature operation, and integrated burst control - making it the only option for high-reliability, high-efficiency packet buffering in telecom infrastructure.

Availability

71V3556SA150BG8 is available at Aetrix Electronics and suitable for high-speed networking equipment, FPGA-based accelerators, and industrial real-time controllers requiring stable component supply, long lifecycle support, and guaranteed industrial temperature performance.

Supply support for 71V3556SA150BG8 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 71V3556SA150BG8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency bus turnaround in high-throughput packet processing and real-time control systems.

FAQ

What does the "SA" suffix indicate in 71V3556SA150BG8?

The "SA" suffix denotes IEEE 1149.1-compliant JTAG boundary scan capability. This version includes dedicated TMS, TDI, TCK, TDO, and optional TRST pins - confirmed in the functional block diagram and pin definitions. The base "S" version omits these signals. The 71V3556SA150BG8 uses the 100-pin TQFP package with JTAG pins assigned to specific locations (e.g., TMS on pin A1, TDI on B1).

Does 71V3556SA150BG8 support both linear and interleaved burst modes?

Yes, the 71V3556SA150BG8 supports both burst sequences via the LBO (Linear/Interleaved Burst Order) pin. When LBO = LOW, it executes linear order (A0, A1, A2, A3); when LBO = HIGH, it uses interleaved order (A0, A2, A1, A3). This behavior is defined in the Linear and Interleaved Burst Sequence Tables and is hardware-controlled - no register programming is required.

How does the ZBT™ feature eliminate dead cycles in 71V3556SA150BG8?

The ZBT™ architecture in the 71V3556SA150BG8 overlaps bus direction change with memory access. After a write cycle completes, the next read command can be issued immediately - the device internally manages bus turnaround without inserting idle cycles. This is achieved via dedicated control logic that decouples R/W state transitions from data bus drivers, enabling 100% bus utilization in mixed read/write workloads.

What is the function of the ZZ (Sleep Mode) pin on 71V3556SA150BG8?

The ZZ pin on the 71V3556SA150BG8 is an active-high synchronous input that gates the internal clock and places the device in ultra-low-power sleep mode while preserving data. When ZZ = HIGH, core logic is powered down but SRAM cells retain contents. Data retention is guaranteed across the full industrial temperature range (–40°C to +85°C), and wake-up occurs on the next valid CLK edge after ZZ returns LOW.

Can 71V3556SA150BG8 operate with only two chip enables asserted?

Yes - the 71V3556SA150BG8 requires CE1 = LOW, CE2 = LOW, and CE2 = HIGH to select the device. Deselection occurs if *any* of these three conditions fails (e.g., CE1 = HIGH, CE2 = HIGH, or CE2 = LOW). The truth table explicitly defines "CE = L" as CE1=L ∧ CE2=L ∧ CE2=H. This triple-enable scheme enables flexible depth expansion without external decoding logic.