Renesas 71V2556SA133BGI

Overview

71V2556SA133BGI from IDT (now Renesas) is a 128K × 36-bit (4.5 Mbit), 3.3V synchronous ZBT™ SRAM with 2.5V I/O, pipelined outputs, and zero-bus-turnaround architecture. It delivers 166 MHz operation (3.5 ns clock-to-data access), supports 4-word linear/interleaved burst modes via internal counter, and features individual byte write (BW1–BW4), three chip enables (CE1/CE2/CE2), and optional IEEE 1149.1 JTAG for boundary scan. It is used in high-speed packet buffering and cache applications in networking line cards.

For engineers reviewing the 71V2556SA133BGI datasheet, 71V2556SA133BGI pinout, 71V2556SA133BGI application, or 71V2556SA133BGI equivalent, key selection considerations include its ZBT™ timing behavior, 100-pin TQFP industrial-grade packaging, 3.3V core / 2.5V I/O supply separation, burst counter control via ADV/LD and LBO, and compatibility with pipelined memory controllers requiring dead-cycle elimination between read/write transitions.

Technical Context

The 71V2556SA133BGI implements a fully synchronous, clock-edge-triggered architecture with input registers for address, data, and control signals. Its ZBT™ operation eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions without idle cycles.

It integrates a 4-word burst counter controlled by ADV/LD and LBO pins to generate sequential addresses; supports both linear and interleaved burst orders; and includes an internally synchronized output buffer enable (OE) that removes external timing constraints on output control. The device also provides optional JTAG test access compliant with IEEE 1149.1.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 1 marked by corner notch; top-view orientation as defined in datasheet drawing 4875 drw 02.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV33-133AXC and AS7C33128P-133BIN, the 71V2556SA133BGI uniquely delivers 166 MHz ZBT™ operation with integrated burst counter and IEEE 1149.1 JTAG-enabling higher throughput, simpler controller design, and production testability in demanding infrastructure applications.

Availability

71V2556SA133BGI is available at Aetrix Electronics and suitable for network packet buffering, high-speed cache memory, telecom line card memory, and test equipment data capture requiring stable component supply across extended industrial temperature ranges.

Supply support for 71V2556SA133BGI 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 71V2556SA133BGI belongs to IDT's ZBT™ SRAM product line, designed specifically for zero-latency, high-throughput memory subsystems in networking and telecom infrastructure where deterministic burst access and bus turnaround elimination are critical.

FAQ

What does the 'SA' suffix in 71V2556SA133BGI indicate?

The 'SA' suffix denotes the version with optional IEEE 1149.1 JTAG boundary-scan capability. Unlike the base 'S' variant, the 71V2556SA133BGI includes functional TMS, TDI, TCK, TDO, and TRST pins routed to dedicated package balls in the 100-pin TQFP, enabling in-system test and debug of PCB interconnects.

How does the ZBT™ feature of the 71V2556SA133BGI eliminate dead cycles?

The 71V2556SA133BGI's ZBT™ architecture allows immediate transition from a write cycle to a read cycle (or vice versa) without inserting idle clock cycles. This is achieved through internal pipeline staging and synchronized output enable, ensuring the bus remains active and data flows continuously-critical for line-rate packet processing.

Can the 71V2556SA133BGI operate with only VDD powered, leaving VDDQ unconnected?

No. The 71V2556SA133BGI requires both VDD (3.3V ±5%) and VDDQ (2.5V ±5%) to be actively supplied within specification. I/O drivers and input receivers depend on VDDQ; operating without it risks undefined data states, excessive current draw, or permanent damage per Absolute Maximum Ratings.

What is the function of the ADV/LD and LBO pins on the 71V2556SA133BGI?

ADV/LD controls the burst counter: LOW loads an external address; HIGH increments the internal counter. LBO selects burst order: LOW enables linear sequence (0,1,2,3); HIGH enables interleaved (0,2,1,3). Together, they define how the 71V2556SA133BGI generates four sequential addresses per burst command.

Is the 71V2556SA133BGI pin-compatible with other members of the 71V2556 family?

Yes-the 71V2556SA133BGI shares identical pinout and footprint with other 100-pin TQFP variants in the 71V2556 family (e.g., 71V2556S133BG, 71V2556SA100BGI). Differences lie in speed grade, temperature range, and JTAG inclusion-not physical layout-enabling drop-in replacement where timing and feature requirements align.