Renesas 71V2556S100PFG8

Overview

71V2556S100PFG8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit organization (4.5 Mbit), 166 MHz operation (3.5 ns clock-to-data access), pipelined outputs, and zero-bus-turnaround architecture. It supports 4-word linear/interleaved burst reads/writes, individual byte write control (BW1–BW4), and operates across industrial temperature (–40°C to +85°C) in a 100-pin TQFP package - deployed in high-speed network packet buffers and telecom line-card memory subsystems.

For engineers reviewing the 71V2556S100PFG8 datasheet, 71V2556S100PFG8 pinout, 71V2556S100PFG8 application, or 71V2556S100PFG8 equivalent, key selection considerations include its ZBT timing behavior, 2.5V I/O supply compatibility, burst counter control via ADV/LD and LBO, and JEDEC-standard TQFP-100 mechanical footprint for board-level integration.

Technical Context

The 71V2556S100PFG8 implements a fully synchronous, clock-edge-triggered architecture with input registers for address, data, and control signals, enabling deterministic pipelined operation. Its internal burst counter advances on ADV/LD = HIGH and loads external addresses on ADV/LD = LOW, supporting both linear and interleaved sequences selected by the LBO pin.

It features three chip enables (CE1, CE2, CE2) for depth expansion, a single R/W pin, and internally synchronized OE elimination - removing external timing constraints on output enable. Clock Enable (CEN) suspends all synchronous logic while preserving register state, and optional IEEE 1149.1 JTAG (not implemented in "S" version) supports boundary-scan testability.

Key Specifications

Pinout & Package

71V2556S100PFG8 is packaged in a 100-pin plastic thin quad flatpack (TQFP), JEDEC MO-145 compliant, with 0.5 mm pitch and 14 mm × 20 mm body size. Pin 1 is located at top-left corner (marking dot adjacent), 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 CY7C1356BV18-167BZC and AS7C33128PFS-10BIN, the 71V2556S100PFG8 delivers superior throughput via ZBT architecture and burst pipelining, but requires dual-supply design and precise ADV/LD sequencing - making it optimal for latency-critical telecom infrastructure rather than general-purpose buffering.

Availability

71V2556S100PFG8 is available at Aetrix Electronics and suitable for network packet buffers, telecom line-card memory, baseband processor caches, and ruggedized industrial controllers requiring stable component supply, long-lifecycle support, and industrial-temperature reliability.

Supply support for 71V2556S100PFG8 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 interface, and RF solutions for communications and computing markets.

The 71V2556S100PFG8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency bus turnaround in high-speed packet-switching, base station, and real-time signal processing systems demanding deterministic memory access.

FAQ

What is the function of the ADV/LD pin on the 71V2556S100PFG8?

The ADV/LD pin on the 71V2556S100PFG8 controls the internal burst counter: when ADV/LD is LOW, it loads an external address into the counter; when HIGH, it increments the counter to generate the next burst address. This enables efficient 4-word burst access without repeated address bus updates, and the 71V2556S100PFG8 relies on this pin for both linear and interleaved burst modes depending on LBO state.

Does the 71V2556S100PFG8 support JTAG boundary scan?

No, the 71V2556S100PFG8 does not support JTAG boundary scan. The "S" suffix denotes the standard version without IEEE 1149.1 functionality; JTAG is only available on the "SA" variant (e.g., 71V2556SA). Pins TMS, TDI, TCK, TDO, and TRST are NC (no connect) on the 71V2556S100PFG8 and must be left unconnected or tied to appropriate voltage levels per datasheet guidance.

How does the ZBT™ feature improve system performance in the 71V2556S100PFG8?

The ZBT™ (Zero Bus Turnaround) feature in the 71V2556S100PFG8 eliminates dead cycles between consecutive read and write operations - allowing immediate transition from one to the other without bus idle time. This increases effective memory bandwidth by up to 30% in mixed-access workloads, and the 71V2556S100PFG8 achieves this through internal pipeline synchronization and dedicated burst counter logic, not external timing control.

What are the voltage requirements for VDD and VDDQ on the 71V2556S100PFG8?

The 71V2556S100PFG8 requires VDD = 3.3 V ±5% for core logic and VDDQ = 2.5 V for I/O drivers. These supplies are separate and must be independently decoupled; VDDQ may not exceed 2.625 V or drop below 2.375 V, and VDD must remain within 3.135–3.465 V. Exceeding these ranges risks timing violations or latch-up, and the 71V2556S100PFG8 specifies no operational guarantee outside these limits.

Can the 71V2556S100PFG8 operate in linear burst mode only?

No, the 71V2556S100PFG8 supports both linear and interleaved burst modes. The LBO (Linear/Interleaved Burst Order) pin selects the sequence: tied to VSS for linear (0,1,2,3), or to VDD for interleaved (0,2,1,3). This selection is static per power-on cycle and directly affects how the internal burst counter increments, and the 71V2556S100PFG8's functional timing diagrams confirm distinct address sequences for each mode.