Renesas 71V3556S166PFGI

Overview

71V3556S166PFGI from IDT (now Renesas) is a 128K × 36-bit, 4.5 Mbit, 3.3V synchronous ZBT™ SRAM with zero bus turnaround, pipelined outputs, and 166 MHz operation (3.5 ns clock-to-data access). It features 4-word burst capability (linear/interleaved), individual byte write control (BW1–BW4), and three chip enables for depth expansion. Used in high-speed networking packet buffers and telecom line cards requiring deterministic latency and no dead cycles between read/write transitions.

For engineers reviewing the 71V3556S166PFGI datasheet, 71V3556S166PFGI pinout, 71V3556S166PFGI application, or 71V3556S166PFGI equivalent, key selection criteria include ZBT™ timing compliance, TQFP-100 package compatibility, industrial temperature support (–40°C to +85°C), 3.3V core/I/O supply tolerance (±5%), and JTAG boundary scan option availability.

Technical Context

The 71V3556S166PFGI implements a fully synchronous, positive-edge-triggered architecture with registered address, data, and control inputs. Its ZBT™ feature eliminates bus turnaround dead cycles by enabling immediate read-after-write or write-after-read transitions without wait states.

It integrates an on-chip burst counter controlled by ADV/LD and LBO pins, supporting both linear and interleaved 4-word burst sequences. Output enable (OE) is asynchronous, while all other inputs-including CEN, CE1/CE2/CE2, R/W, BWx, and CLK-are synchronized to the rising edge of the 166 MHz clock.

Key Specifications

Pinout & Package

71V3556S166PFGI is packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, with 0.5 mm pitch. Pin 64 supports ZZ (sleep mode) on latest die revision; pins 14, 16, and 66 tolerate VIH-level input without direct VDD connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV18-166BZI and AS7C33128PFSIG, the 71V3556S166PFGI uniquely delivers 128K × 36-bit density with ZBT™ timing, 4-word burst, and individual byte write-making it irreplaceable in applications demanding deterministic bus utilization and minimal latency jitter.

Availability

71V3556S166PFGI is available at Aetrix Electronics and suitable for high-speed packet buffering, telecom line card memory, industrial PLC data logging, and medical imaging frame store applications requiring stable component supply across extended product lifecycles.

Supply support for 71V3556S166PFGI 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 71V3556S166PFGI belongs to IDT's ZBT™ SRAM product line, designed specifically for applications demanding zero bus turnaround, burst access, and deterministic latency in high-speed data-path subsystems.

FAQ

What is the memory organization and total capacity of the 71V3556S166PFGI?

The 71V3556S166PFGI is organized as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This configuration supports a 36-bit-wide data bus with four 9-bit bytes (I/O0–I/O31 plus I/OP1–I/OP4 parity bits), enabling full-word or granular byte writes via BW1–BW4 controls. The device does not support 256K × 18 mode-only the 128K × 36 variant is implemented in this specific part number.

Does the 71V3556S166PFGI support ZBT™ (Zero Bus Turnaround) functionality, and how is it implemented?

Yes, the 71V3556S166PFGI fully implements ZBT™ functionality. It eliminates dead cycles between consecutive read and write operations by allowing immediate bus direction reversal-no wait states are inserted. This is achieved through internal synchronization of address, control, and data registers on the rising edge of CLK, combined with pipelined output buffering and asynchronous OE. The result is deterministic 3.5 ns clock-to-data access and seamless back-to-back transactions critical for packet buffering.

What package type and pin count does the 71V3556S166PFGI use, and is it RoHS compliant?

The 71V3556S166PFGI uses a 100-pin plastic thin quad flatpack (TQFP) package, JEDEC standard, with 14 mm × 20 mm body size and 0.5 mm lead pitch. The "G" in the suffix denotes green (halogen-free, RoHS-compliant) construction. Pin 64 supports ZZ (sleep mode) on the latest die revision, and pins 14, 16, and 66 may be left unconnected to VDD if driven above VIH.

How does the burst counter operate in the 71V3556S166PFGI, and what controls burst order?

The 71V3556S166PFGI's burst counter advances automatically on each rising CLK edge when ADV/LD is high, generating four sequential addresses per burst. Burst order is selected by the LBO pin: LBO = low enables linear sequence (e.g., A0, A1, A2, A3), while LBO = high selects interleaved (e.g., A0, A2, A1, A3). The counter wraps upon completion, and ADV/LD = low loads a new external address to restart the burst. This hardware counter offloads burst address generation from the controller.

What are the voltage and temperature specifications for reliable operation of the 71V3556S166PFGI?

The 71V3556S166PFGI operates with VDD = 3.3 V ±5% (3.135 V to 3.465 V) and VDDQ = 3.3 V ±5%, with VSS = 0 V. It is rated for industrial temperature range: –40°C to +85°C case temperature. Absolute maximum ratings include terminal voltage up to VDD + 0.5 V on I/O pins and –0.5 V to +4.6 V on all other terminals. Power dissipation is limited to 2.0 W.