Renesas 71V67703S85BG

Overview

71V67703S85BG from IDT (now Renesas) is a 256K × 36-bit or 512K × 18-bit 3.3V synchronous SRAM with flow-through outputs, single-cycle deselect, and burst-mode operation. It supports 8.5ns access time at up to 87MHz clock frequency, features LBO-controlled linear/interleaved burst sequencing, self-timed write with global and byte-level write enables, and industrial temperature range (–40°C to +85°C). It is used in high-bandwidth networking and telecom data buffering where deterministic latency and burst throughput are critical.

For engineers reviewing the 71V67703S85BG datasheet, 71V67703S85BG pinout, 71V67703S85BG application, or 71V67703S85BG equivalent, key selection criteria include its JEDEC-standard 100-pin TQFP package, 3.3V core/I/O supply compatibility, flow-through output architecture eliminating output register delay, ZZ-controlled sleep mode for low-power standby, and support for both interleaved and linear burst addressing via the LBO pin.

Technical Context

The 71V67703S85BG implements a synchronous, clock-driven interface with all control inputs (CE, CS0, CS1, ADSP, ADSC, ADV, GW, BWE, BW1–BW4, OE, LBO, ZZ) sampled on the rising edge of CLK except OE and ZZ, which are asynchronous. Its internal burst address counter advances on ADV=LOW and wraps after four cycles, with sequence order determined by LBO state (LOW = linear, HIGH = interleaved).

It uses a flow-through output architecture-no output register-so valid data appears at I/O pins within tCD (≤8.5ns) after the rising clock edge, enabling zero-cycle output latency. Write operations are self-timed: the internal logic completes the write cycle without external timing control, using either global write (GW) or byte-write (BWE + BWx) activation synchronized to CLK.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin thin plastic quad flatpack (TQFP), 14mm × 20mm body, lead pitch 0.5mm. Pin 1 marked by dot; top-side view shown in datasheet drawing 5309 drw 02a.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1373KV18 and AS7C33128PFSIG, the 71V67703S85BG uniquely delivers 8.5ns flow-through latency in a drop-in 100-pin TQFP with configurable burst order and hardware sleep control-making it optimal for latency-critical, power-aware, and layout-constrained industrial and telecom designs.

Availability

71V67703S85BG is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and radar signal processing applications requiring stable component supply, long-lifecycle support, and industrial-temperature qualification.

Supply support for 71V67703S85BG 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 71V67703S85BG belongs to IDT's high-speed synchronous SRAM product line, designed specifically for applications demanding deterministic latency, burst throughput, and industrial reliability in networking and real-time embedded systems.

FAQ

What memory organization does the 71V67703S85BG support?

The 71V67703S85BG supports two configurations: 256K × 36-bit (address range A0–A17) or 512K × 18-bit (A0–A18), selected by address decoding and pin strapping. Both configurations share identical timing, packaging, and control logic, allowing flexible system-level memory mapping without changing the 71V67703S85BG footprint or firmware interface.

How does the LBO pin affect burst behavior in the 71V67703S85BG?

In the 71V67703S85BG, the LBO pin statically configures burst order: when pulled LOW, it enables linear burst (00→01→10→11); when pulled HIGH, it enables interleaved burst (00→01→11→10). LBO must remain stable during operation-changing it mid-burst causes undefined address sequencing. This matches common processor cache line layouts and enables optimization for specific DMA or prefetch patterns.

What is the role of the ZZ pin in the 71V67703S85BG?

The ZZ pin in the 71V67703S85BG provides asynchronous entry into full sleep mode: asserting ZZ HIGH gates the internal clock and reduces supply current to ≤70mA while guaranteeing data retention across the full industrial temperature range. Unlike standby modes, ZZ sleep requires no clock or control signal sequencing-making it ideal for rapid power gating in burst-idle intervals.

Does the 71V67703S85BG support byte-level writes, and how are they enabled?

Yes, the 71V67703S85BG supports independent 9-bit byte writes via BW1–BW4, each controlling one 9-bit segment of the 36-bit I/O bus (e.g., BW1 → I/O0–7 + I/OP1). Byte writes require BWE=LOW to enable the BWx signals; if BWE=HIGH, only GW-controlled full-word writes are possible. This enables precise data updates without disturbing adjacent bytes-critical for protocol header manipulation.

What is the significance of "flow-through outputs" in the 71V67703S85BG?

"Flow-through outputs" means the 71V67703S85BG has no output register: data from the memory array appears directly at the I/O pins within tCD ≤8.5ns after the rising CLK edge. This eliminates register-induced skew and jitter, ensures deterministic zero-cycle output latency, and allows downstream logic (e.g., FPGA fabric or ASIC datapaths) to sample data on the same clock edge-essential for timing-critical interfaces like SerDes buffers.