Renesas 71V65903S85PFG

Overview

71V65903S85PFG from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM organized as 512K × 18 (9,437,184-bit), supporting 100 MHz operation with 7.5 ns clock-to-data access. It implements zero bus turnaround (ZBT) architecture to eliminate dead cycles between read/write transitions, features flow-through outputs, and uses a synchronous burst counter for 4-word interleaved or linear bursts. It serves as high-speed buffer memory in network packet processors and telecom line cards requiring deterministic latency.

For engineers reviewing the 71V65903S85PFG datasheet, 71V65903S85PFG pinout, 71V65903S85PFG application, or 71V65903S85PFG equivalent, key selection criteria include ZBT timing compliance, 3.3V I/O supply (VDDQ) tolerance, industrial temperature support (–40°C to +85°C), TQFP-100 package compatibility, and byte-write enable (BW1–BW2) control for x18 configuration.

Technical Context

The 71V65903S85PFG employs a synchronous dual-register architecture: address/control inputs are registered on the rising CLK edge with ADV/LD low for load operations, while data input is registered and output is flow-through (no output register). Its burst counter advances on ADV/LD high, enabling four-cycle data transfers per address with LBO selecting interleaved or linear order.

It supports three chip enables (CE1, CE2 active-low; CE2 active-high) for depth expansion, asynchronous OE and ZZ controls, and CEN-suspended operation. The device guarantees data retention in sleep mode (ZZ = HIGH) and tri-states its I/O bus one cycle after deselect - critical for multi-SRAM bus arbitration in high-throughput systems.

Key Specifications

Pinout & Package

Packaged in JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm footprint, lead-free and RoHS-compliant. Pinout optimized for signal integrity with distributed VDDQ/VSS pairs and dedicated ground planes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1372KV18 and AS7C35128P, the 71V65903S85PFG uniquely delivers ZBT timing and integrated burst counter in a pin-compatible TQFP-100 package - enabling drop-in replacement in legacy IDT-based systems while maintaining deterministic sub-10 ns latency.

Availability

71V65903S85PFG is available at Aetrix Electronics and suitable for network infrastructure, telecom line cards, and industrial control systems requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for 71V65903S85PFG 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 71V65903S85PFG belongs to IDT's ZBT SRAM product line, engineered specifically for low-latency, high-throughput packet buffering and real-time signal processing in carrier-grade networking equipment.

FAQ

What is the memory organization of the 71V65903S85PFG?

The 71V65903S85PFG is organized as 512K × 18, delivering 9,437,184 bits of storage. This configuration uses 19 address lines (A0–A18), with A0–A17 selecting one of 512K locations and A18 reserved for future expansion or bank selection. It does not support the 256K × 36 mode - that is exclusive to the 71V65703 variant.

Does the 71V65903S85PFG support burst mode, and how is it configured?

Yes, the 71V65903S85PFG supports 4-word burst mode using an internal synchronous counter. Burst sequence order (interleaved or linear) is selected by the LBO pin: LBO = HIGH enables interleaved, LBO = LOW enables linear. Burst initiation occurs when ADV/LD is sampled HIGH at the rising CLK edge, and the counter wraps automatically after four words.

What are the voltage requirements for VDD and VDDQ on the 71V65903S85PFG?

The 71V65903S85PFG requires VDD = 3.3 V ±5% (3.135 V to 3.465 V) for core logic and VDDQ = 3.3 V ±5% (3.135 V to 3.465 V) for I/O drivers. These supplies may be derived from separate regulators to minimize noise coupling; VDDQ must not exceed VDD + 0.5 V per absolute maximum ratings.

How does the 71V65903S85PFG handle chip select and deselection?

The 71V65903S85PFG uses three chip enables: CE1 and CE2 (active-low) plus CE2 (active-high). The device is enabled only when CE1 = LOW, CE2 = LOW, and CE2 = HIGH. Deselection initiates on the rising CLK edge when any CE violates this condition, and the I/O bus tri-states exactly one clock cycle later - ensuring clean bus release without glitches.

Is the 71V65903S85PFG compatible with industrial temperature operation?

Yes, the 71V65903S85PFG is fully specified and tested for industrial temperature operation from –40°C to +85°C. This includes validation of AC timing parameters (e.g., 7.5 ns tCD), DC characteristics (leakage, VIH/VIL), and functional reliability across the full range - making it suitable for deployment in outdoor telecom enclosures and factory automation systems.