Renesas 71V65703S85BGI8

Overview

71V65703S85BGI8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM organized as 256K × 36 (9,437,184-bit), delivering 100 MHz operation with 7.5 ns clock-to-data access, zero bus turnaround between read/write cycles, and flow-through outputs. It serves as high-speed buffer/cache memory in network switches, telecom line cards, and packet processing engines requiring deterministic latency and burst data throughput.

For engineers reviewing the 71V65703S85BGI8 datasheet, 71V65703S85BGI8 pinout, 71V65703S85BGI8 application, or 71V65703S85BGI8 equivalent, key selection criteria include its ZBT architecture eliminating dead cycles, 4-word interleaved/linear burst capability, individual byte write control (BW1–BW4), and industrial-grade temperature support (–40°C to +85°C) in TQFP-100 package.

Technical Context

The 71V65703S85BGI8 implements a synchronous, clocked interface with all address/control inputs registered on the rising CLK edge. Its internal burst counter advances on ADV/LD = HIGH, supporting both linear and interleaved sequences selected by LBO. The device uses flow-through output architecture-no output register-enabling immediate data availability one cycle after address/control registration.

It features three chip enables (CE1, CE2 active-low; CE2 active-high) for depth expansion, asynchronous OE and ZZ controls, and a single R/W pin to distinguish read/write operations. Clock Enable (CEN) suspends all synchronous logic while preserving register state, and power-down mode (ZZ = HIGH) guarantees data retention at minimal current draw.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), the 71V65703S85BGI8 provides full signal access for high-speed synchronous SRAM interfacing, including dedicated byte write enables, burst control, and independent core/I/O supplies.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-100BGXI and AS7C3256A-10JIN, the 71V65703S85BGI8 uniquely delivers zero bus turnaround within a synchronous, burst-capable, industrial-temperature SRAM - making it optimal for deterministic high-throughput buffering where every clock cycle must carry valid data.

Availability

71V65703S85BGI8 is available at Aetrix Electronics and suitable for network packet buffering, telecom line card caching, baseband processing, radar signal FIFOs, and industrial embedded controllers requiring stable component supply and long-term lifecycle assurance.

Supply support for 71V65703S85BGI8 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 infrastructure.

The 71V65703S85BGI8 belongs to IDT's ZBT™ SRAM product line, designed specifically for ultra-low-latency, high-bandwidth buffering in networking, telecom, and military/aerospace systems demanding deterministic timing and industrial reliability.

FAQ

What is the memory organization and total capacity of the 71V65703S85BGI8?

The 71V65703S85BGI8 is organized as 256K × 36, providing 9,437,184 bits (9.4 Mbit) of synchronous SRAM. This configuration supports 36-bit wide data transfers and is optimized for systems requiring high-bandwidth buffering with minimal address bus overhead. It is pin-compatible with the 512K × 18 variant (71V65903) in the same family, allowing flexible density selection without board redesign.

Does the 71V65703S85BGI8 support burst read and write operations, and how is burst order controlled?

Yes, the 71V65703S85BGI8 supports 4-word burst operations in both read and write modes. Burst sequence order is selected via the LBO (Linear/Interleaved Burst Order) pin: LBO = LOW enables linear addressing (A0, A1, A2, A3), while LBO = HIGH selects interleaved order (A0, A2, A1, A3). The ADV/LD pin controls whether a new external address is loaded (LOW) or the internal burst counter is advanced (HIGH), enabling seamless burst execution.

How does the ZBT™ (Zero Bus Turnaround) feature function in the 71V65703S85BGI8?

The ZBT™ feature in the 71V65703S85BGI8 eliminates idle bus cycles between consecutive read and write operations. Unlike conventional SRAMs that require turnaround time to change bus direction, the 71V65703S85BGI8 allows immediate back-to-back access - e.g., a write cycle can be followed directly by a read cycle on the next clock edge without inserting wait states. This is achieved through internal bus steering and flow-through output architecture.

What are the power supply requirements and thermal specifications for the 71V65703S85BGI8?

The 71V65703S85BGI8 requires two independent 3.3 V supplies: VDD (core logic, 3.3 V ±5%) and VDDQ (I/O interface, 3.3 V ±5%). It operates across the industrial temperature range of –40°C to +85°C and supports power-down mode via the ZZ pin (active-high), which gates the internal clock and reduces current draw while maintaining data retention. Absolute maximum ratings include VTERM up to +4.6 V and storage temperature from –55°C to +125°C.

Can the 71V65703S85BGI8 perform partial-word writes, and how is this implemented?

Yes, the 71V65703S85BGI8 supports individual byte write operations using four dedicated active-low signals: BW1, BW2, BW3, and BW4. Each controls a 9-bit lane - BW1 covers I/O[0:7] + I/OP1, BW2 covers I/O[8:15] + I/OP2, etc. When a BWx signal is LOW during a write cycle, the corresponding 9-bit byte is updated; other bytes remain unchanged. This eliminates the need for destructive read-modify-write sequences in cache or descriptor table updates.