Renesas 71V65903S85BQ8

Overview

71V65903S85BQ8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM organized as 512K × 18 bits (9,437,184-bit capacity), featuring zero bus turnaround, flow-through outputs, and 4-word burst capability. It operates at 100 MHz with 7.5 ns clock-to-data access, supports linear/interleaved burst modes via LBO pin, and targets high-speed cache and buffer applications in networking and telecom systems.

For engineers reviewing the 71V65903S85BQ8 datasheet, 71V65903S85BQ8 pinout, 71V65903S85BQ8 application, or 71V65903S85BQ8 equivalent, key selection criteria include its 100 MHz synchronous interface, ZBT architecture eliminating dead cycles between read/write transitions, 3.3V core/I/O supply compliance, industrial temperature range (–40°C to +85°C), and JEDEC-standard 100-pin TQFP package (PKG100).

Technical Context

The 71V65903S85BQ8 implements a synchronous, clock-driven architecture where address/control signals are registered on the rising CLK edge, and data transfers occur one cycle later. Its internal burst counter advances on ADV/LD = HIGH, supporting both linear and interleaved sequences selected by the static LBO input.

It features three chip enables (CE1, CE2 active-low; CE2 active-high) for flexible depth expansion, individual byte write controls (BW1–BW4), and asynchronous OE and ZZ inputs for output enable and sleep mode-enabling low-power operation with guaranteed data retention during ZZ assertion.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm footprint, with exposed pad thermal design. Pinout conforms to PKG100 configuration for 512K × 18 variant per datasheet drawing 5298 drw 02a.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1372D-100AXC and AS7C3512P-10JCN, the 71V65903S85BQ8 uniquely delivers zero bus turnaround, flow-through outputs, and integrated burst counter-reducing system-level timing complexity and maximizing effective bandwidth in high-speed synchronous designs.

Availability

71V65903S85BQ8 is available at Aetrix Electronics and suitable for high-speed network packet buffering, telecom line card cache memory, industrial PLC real-time data logging, and avionics display frame buffering requiring stable component supply across extended product lifecycles.

Supply support for 71V65903S85BQ8 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 71V65903S85BQ8 belongs to IDT's ZBT™ SRAM product line, designed specifically for applications demanding deterministic, low-latency memory access with zero bus turnaround-targeting networking infrastructure, base stations, and real-time embedded systems.

FAQ

What is the memory organization and total capacity of the 71V65903S85BQ8?

The 71V65903S85BQ8 is organized as 512K × 18 bits, delivering a total capacity of 9,437,184 bits (9.4 Mbit). This configuration uses 19 address lines (A0–A18) and provides an 18-bit data bus (I/O0–I/O15 plus I/OP1–I/OP2), optimized for systems requiring balanced width and depth without external multiplexing. The 71V65903S85BQ8 supports depth expansion via three chip enables.

Does the 71V65903S85BQ8 support burst read and write operations, and how is burst order controlled?

Yes, the 71V65903S85BQ8 supports 4-word burst operations for both reads and writes. Burst order-linear or interleaved-is selected by the static LBO (Linear/Interleaved Burst Order) pin: LBO = LOW selects linear sequence, LBO = HIGH selects interleaved. The burst counter advances on ADV/LD = HIGH, and the initial address is loaded when ADV/LD = LOW, ensuring predictable, hardware-controlled burst behavior without CPU intervention.

What is the significance of ZBTTM architecture in the 71V65903S85BQ8, and how does it improve system performance?

ZBTTM (Zero Bus Turnaround) architecture in the 71V65903S85BQ8 eliminates idle cycles when switching between read and write operations. Unlike conventional SRAMs requiring bus release/reacquisition, the 71V65903S85BQ8 allows immediate back-to-back access-e.g., a write cycle can be followed directly by a read cycle on the next clock edge. This increases effective bus utilization by up to 25% in mixed-access workloads common in packet buffering and cache applications.

How does the 71V65903S85BQ8 handle power management, and what is the role of the ZZ pin?

The 71V65903S85BQ8 implements low-power sleep mode via the asynchronous ZZ pin. When ZZ is driven HIGH, the internal clock is gated, reducing dynamic power consumption to minimum while guaranteeing data retention across the full industrial temperature range (–40°C to +85°C). This enables energy-efficient operation in intermittently active systems like remote sensors or standby communication modules without requiring data reload on wake-up.

What package type and pin count does the 71V65903S85BQ8 use, and is it compatible with standard PCB footprints?

The 71V65903S85BQ8 is packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), designated PKG100, with 14 mm × 20 mm body dimensions and 0.5 mm lead pitch. Its pinout matches the 512K × 18 configuration shown in datasheet drawing 5298 drw 02a, and it is fully compatible with industry-standard TQFP-100 footprints-enabling drop-in use in existing layouts designed for functionally equivalent IDT ZBT SRAMs.