Renesas 71V65903S85BQG8

Overview

71V65903S85BQG8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM organized as 512K × 18 bits (9,437,184-bit capacity), supporting 100 MHz operation with 7.5 ns clock-to-data access time. It implements zero bus turnaround (ZBT) architecture to eliminate dead cycles between read/write transitions, features flow-through outputs, and includes an on-chip burst counter for 4-word interleaved or linear bursts - used in high-speed networking packet buffers and telecom line-card memory subsystems.

For engineers reviewing the 71V65903S85BQG8 datasheet, 71V65903S85BQG8 pinout, 71V65903S85BQG8 application, or 71V65903S85BQG8 equivalent, key selection criteria include its 100 MHz synchronous interface, 3.3V core/I/O supply, industrial temperature range (–40°C to +85°C), TQFP-100 package, and support for individual byte write control via BW1–BW2 pins in x18 configuration.

Technical Context

The 71V65903S85BQG8 uses a synchronous CMOS architecture with registered address/control inputs triggered on the rising edge of CLK, while data outputs are flow-through (no output register). Its internal burst counter advances on ADV/LD = HIGH and loads new addresses on ADV/LD = LOW, with burst order selected by static LBO pin (interleaved when high, linear when low).

It supports three chip enables (CE1, CE2 active-low; CE2 active-high) for depth expansion, asynchronous OE and ZZ controls, and Clock Enable (CEN) to suspend operation without disrupting internal state. The device guarantees data retention in ZZ sleep mode and tri-states the I/O bus one cycle after deselection.

Key Specifications

Pinout & Package

Packaged in JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch, lead-free and RoHS-compliant (suffix "G" in part number). Pin 1 marked by dot; top-side marking includes "71V65903S85BQG8" and date code.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1371DV33-100AXC and AS7C35128PFS-10BIN, the 71V65903S85BQG8 delivers deterministic ZBT timing and integrated burst control in a single TQFP-100 package - reducing FPGA resource usage and simplifying timing closure in high-speed packet-processing designs.

Availability

71V65903S85BQG8 is available at Aetrix Electronics and suitable for telecom line cards, network packet buffers, industrial PLC backplanes, and avionics data recorders requiring stable component supply across extended product lifecycles.

Supply support for 71V65903S85BQG8 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), acquired by Renesas Electronics in 2019, specializes in high-performance timing, memory interface, and RF power solutions for communications and computing infrastructure.

The 71V65903S85BQG8 belongs to IDT's ZBT™ SRAM family, designed specifically for low-latency, high-bandwidth memory subsystems in carrier-grade networking and real-time industrial control systems.

FAQ

What is the maximum operating frequency of the 71V65903S85BQG8?

The 71V65903S85BQG8 is rated for 100 MHz operation, corresponding to a 10 ns clock cycle time. This is validated across the full industrial temperature range (–40°C to +85°C) and 3.3 V ±5% supply conditions. Its 7.5 ns clock-to-data access time ensures data validity within the first half of the subsequent cycle, enabling tight timing margins in high-speed interfaces.

Does the 71V65903S85BQG8 support burst mode in 512K × 18 configuration?

Yes, the 71V65903S85BQG8 supports 4-word burst mode in both 256K × 36 and 512K × 18 configurations. In x18 mode, burst addressing uses A0–A18 with LBO selecting interleaved or linear sequence. The internal burst counter advances on ADV/LD = HIGH, eliminating need for external address generation logic.

How does the ZBT™ architecture of the 71V65903S85BQG8 improve system performance?

The ZBT™ architecture in the 71V65903S85BQG8 eliminates dead cycles between read and write operations by allowing immediate bus direction reversal. Unlike conventional synchronous SRAMs requiring wait states, it achieves continuous data flow - increasing effective bandwidth by up to 30% in mixed-access scenarios typical of packet buffering and real-time control.

What is the function of the CE2 pin on the 71V65903S85BQG8?

The CE2 pin on the 71V65903S85BQG8 is an active-high chip enable, complementary in polarity to CE1 and CE2 (both active-low). It enables flexible depth expansion: asserting CE1 = LOW, CE2 = LOW, and CE2 = HIGH selects the device; any deviation (e.g., CE2 = LOW) deselects it - allowing hierarchical memory decoding with minimal external logic.

Can the 71V65903S85BQG8 retain data during power-down?

Yes, the 71V65903S85BQG8 retains data in Sleep Mode when the ZZ pin is driven HIGH. In this state, internal clock gating reduces ICC to ≤10 µA while maintaining full memory content integrity. Data retention is guaranteed over the full industrial temperature range and requires only VDD/VDDQ bias - no backup battery or capacitor needed.