Renesas 71V3557S80PFG

Overview

71V3557S80PFG from Integrated Device Technology is a 128K × 36-bit (4.5 Mbit), 3.3V synchronous ZBT™ SRAM with flow-through outputs, 100 MHz operation (7.5 ns clock-to-data access), and zero bus turnaround architecture. It supports interleaved/linear 4-word burst reads/writes, individual byte write control (BW1–BW4), and JTAG boundary scan (IEEE 1149.1). It is used in high-speed packet buffering and cache subsystems of network switches and telecom line cards.

For engineers reviewing the 71V3557S80PFG datasheet, 71V3557S80PFG pinout, 71V3557S80PFG application, or 71V3557S80PFG equivalent, key selection considerations include its synchronous burst counter, sleep mode (ZZ), three chip enables for depth expansion, 100-pin TQFP package, and compatibility with 3.3V I/O and core supply rails.

Technical Context

The 71V3557S80PFG implements a synchronous dual-register architecture: address/control signals are latched on the rising edge of CLK when ADV/LD is low and chip enables are asserted, while data input is registered and output is flow-through (no output register). Its ZBT™ feature eliminates dead cycles between read/write transitions by enabling immediate bus turnaround without OE timing constraints.

It integrates a programmable burst counter controlled by ADV/LD and LBO (linear/interleaved), supports asynchronous OE for output tri-state control, and includes optional IEEE 1149.1 JTAG test logic with TMS/TDI/TCK/TDO/TRST pins. Sleep mode (ZZ) gates the internal clock to reduce power while retaining memory contents.

Key Specifications

Pinout & Package

71V3557S80PFG is packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 1 is marked by a dot; pins are numbered counterclockwise from top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV18-100BGXI and AS7C33128PFSIG, the 71V3557S80PFG uniquely delivers ZBT™ bus turnaround, programmable burst sequencing, and integrated sleep mode - making it optimal for latency-critical, power-aware, and burst-intensive embedded memory subsystems.

Availability

71V3557S80PFG is available at Aetrix Electronics and suitable for network packet buffering, telecom line card cache, high-speed protocol acceleration, and industrial control data logging requiring stable component supply and long-term industrial-grade availability.

Supply support for 71V3557S80PFG 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

Integrated Device Technology (IDT) is a fabless semiconductor company specializing in timing, memory interface, RF, and power management ICs for communications, computing, and industrial markets.

The 71V3557S80PFG belongs to IDT's ZBT™ SRAM product line, designed specifically for high-speed, low-latency memory subsystems in networking infrastructure and real-time embedded systems demanding deterministic access and zero bus turnaround.

FAQ

What is the memory organization and total capacity of the 71V3557S80PFG?

The 71V3557S80PFG is organized as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This configuration supports 36-bit wide data paths ideal for 32-bit systems with parity or ECC overhead. It is pin-compatible with the 256K × 18 variant (71V3559S80PFG) for flexible density scaling.

Does the 71V3557S80PFG support burst read and write operations, and how is burst order selected?

Yes, the 71V3557S80PFG supports 4-word synchronous burst reads and writes. Burst order is selected via the LBO (Linear/Interleaved Burst Order) pin: LBO = LOW selects linear sequence (A0, A1, A2, A3); LBO = HIGH selects interleaved (A0, A1, A2, A3 in bit-reversed address order). The burst counter advances on each rising CLK edge when ADV/LD = HIGH.

How does the ZBT™ (Zero Bus Turnaround) feature work in the 71V3557S80PFG?

ZBT™ eliminates dead cycles between consecutive read and write operations by allowing immediate bus direction reversal without waiting for OE deassertion or additional clock cycles. The 71V3557S80PFG achieves this via flow-through outputs and synchronous control - enabling back-to-back accesses with no idle bus periods, critical for high-throughput packet processing.

What is the function of the ZZ (Sleep Mode) pin on the 71V3557S80PFG, and what power savings does it provide?

The ZZ pin is a synchronous active-high input that gates the internal clock and places the 71V3557S80PFG into low-power sleep mode while retaining memory contents. In sleep mode, core power consumption drops significantly - datasheet specifies standby current under ZZ as <100 µA - enabling energy-efficient operation during idle periods in battery-backed or thermally constrained systems.

Is JTAG boundary scan supported on the 71V3557S80PFG, and which pins are used?

Yes, the 71V3557S80PFG includes optional IEEE 1149.1-compliant JTAG boundary scan. Pins TMS, TDI, TCK, TDO, and optional TRST (with internal pull-up) implement the test access port. JTAG functionality is present in the "S" version per the datasheet; TRST may be left floating if unused, as automatic reset occurs at power-up.