Renesas 71V2556SA133BG8

Overview

71V2556SA133BG8 from IDT (now Renesas) is a 128K × 36-bit (4.5 Mbit), 3.3V synchronous ZBT™ SRAM with pipelined outputs, 133 MHz operation (7.5 ns clock-to-data access), 2.5V I/O supply, and integrated burst counter. It eliminates bus turnaround dead cycles between read/write transitions and supports linear or interleaved 4-word bursts in high-speed networking and packet buffering applications.

For engineers reviewing the 71V2556SA133BG8 datasheet, 71V2556SA133BG8 pinout, 71V2556SA133BG8 application, or 71V2556SA133BG8 equivalent, key selection criteria include ZBT™ zero-turnaround timing, JEDEC-standard 119-ball BGA (BG119) package, industrial temperature support (–40°C to +85°C), JTAG boundary scan capability, and individual byte write control for memory subsystem optimization.

Technical Context

This SRAM implements a fully synchronous, clock-edge-triggered architecture with address, data, and control registers aligned to the rising edge of CLK. Its internal burst counter and ADV/LD-controlled address loading enable deterministic 4-word burst sequences without external logic.

The device integrates three chip enables (CE1/CE2/CE2), single R/W control, and four independent byte write enables (BW1–BW4), allowing flexible depth expansion and partial writes. Optional IEEE 1149.1 JTAG support provides testability in dense PCB layouts.

Key Specifications

Pinout & Package

71V2556SA133BG8 is packaged in a JEDEC-standard 119-ball grid array (BG119) with 1.0 mm ball pitch, optimized for thermal dissipation and signal integrity in high-speed memory subsystems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV33-133BZI and AS7C33128P-133BIN, the 71V2556SA133BG8 uniquely delivers ZBT™ zero-turnaround operation, 2.5V I/O voltage isolation, and integrated JTAG - making it optimal for high-reliability, high-bandwidth telecom and industrial control memory subsystems requiring deterministic timing and test coverage.

Availability

71V2556SA133BG8 is available at Aetrix Electronics and suitable for packet buffering in networking equipment, cache acceleration in network processors, telecom line card memory subsystems, and real-time industrial data acquisition requiring stable component supply across extended product lifecycles.

Supply support for 71V2556SA133BG8 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 leader specializing in high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The 71V2556SA133BG8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency memory interfaces in high-speed packet-switched systems where deterministic burst access and bus turnaround elimination are critical.

FAQ

What is the maximum operating frequency of the 71V2556SA133BG8?

The 71V2556SA133BG8 is rated for 133 MHz operation, delivering a 7.5 ns clock-to-data access time. This specification is guaranteed over the full industrial temperature range (–40°C to +85°C) and under recommended DC operating conditions (VDD = 3.3 V ±5%, VDDQ = 2.5 V). The device achieves this performance using a fully pipelined synchronous architecture with edge-triggered registers.

Does the 71V2556SA133BG8 support JTAG boundary scan?

Yes, the 71V2556SA133BG8 includes optional IEEE 1149.1-compliant JTAG boundary scan functionality. Pins TMS, TDI, TCK, TDO, and TRST are dedicated to this interface and are implemented in the "SA" variant. TRST is optional and may be left floating (internally pulled to VDD) if not used. JTAG enables in-system testability and interconnect verification without physical probe access.

How does the ZBTTM feature improve system performance in the 71V2556SA133BG8?

The ZBTTM (Zero Bus Turnaround) feature in the 71V2556SA133BG8 eliminates idle cycles between consecutive read and write operations. Unlike conventional SRAMs requiring bus release/reacquisition, this device transitions directly from one operation to the next on the same clock domain - increasing effective memory bandwidth by up to 30% in mixed-access workloads typical of packet buffering and cache coherency protocols.

What is the purpose of the ADV/LD and LBO pins on the 71V2556SA133BG8?

ADV/LD controls whether an external address is loaded (LOW) or the internal burst counter is incremented (HIGH), enabling automatic 4-word burst sequencing. LBO selects burst order: tied to VSS for linear sequence (0,1,2,3), or VDD for interleaved (0,2,1,3). Together, these pins eliminate external burst address generation logic and simplify controller firmware for high-speed memory access patterns.

Is the 71V2556SA133BG8 compatible with industrial temperature requirements?

Yes, the 71V2556SA133BG8 is qualified for industrial temperature operation from –40°C to +85°C. This rating is explicitly confirmed in the manufacturer's datasheet under "Recommended Operating Temperature and Supply Voltage" and applies to the "SA" speed grade. The device uses robust packaging and process technology to maintain timing and electrical specifications across this full range.