Renesas 71V67603S166BQ

Overview

71V67603S166BQ from IDT (now Renesas) is a 256K × 36-bit, 3.3V synchronous SRAM with pipelined outputs, single-cycle deselect, and 166MHz clock operation (3.5ns access time). It supports interleaved/linear burst modes via LBO input, features global and byte-level write control (GW/BWE/BW1–BW4), and operates in commercial temperature range (0°C to +70°C). It is used in high-speed networking buffers and cache subsystems requiring deterministic latency.

For engineers reviewing the 71V67603S166BQ datasheet, 71V67603S166BQ pinout, 71V67603S166BQ application, or 71V67603S166BQ equivalent, key selection factors include its 100-pin TQFP package, 3.3V core/I/O supply, burst counter architecture, ZZ sleep mode support, and compatibility with burst-addressing processors such as PowerPC and MIPS-based controllers.

Technical Context

The 71V67603S166BQ implements a synchronous, clock-driven interface with registered address, data, and control inputs triggered on the rising edge of CLK. Its internal burst logic uses a binary counter to generate four sequential addresses per burst request, with order determined by the static LBO pin state (interleaved or linear).

Write operations are self-timed and configurable: global writes (GW active) write all 36 bits simultaneously, while byte writes (BWE + BW1–BW4) enable selective 9-bit lane updates. Pipelined outputs deliver first data one clock cycle after address latch, enabling sustained 166MHz throughput without wait states.

Key Specifications

Pinout & Package

Packaged in JEDEC-standard 100-pin thin quad flatpack (TQFP), 14mm × 20mm body, 0.5mm pitch. Pinout validated for 256K × 36 configuration per PKG100 drawing (Rev. 6.42, p.5).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-166AXC and AS7C33256P-166JCIN, the 71V67603S166BQ uniquely combines 36-bit width with parity I/O pins, programmable burst order (LBO), and ultra-low-power sleep mode (IZZ ≤ 70µA), making it optimal for cache, networking, and safety-critical buffering where data integrity and power efficiency are co-prioritized.

Availability

71V67603S166BQ is available at Aetrix Electronics and suitable for network packet buffering, processor cache interfaces, and industrial PLC memory modules requiring stable component supply, long-term lifecycle support, and commercial-grade reliability.

Supply support for 71V67603S166BQ 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 71V67603S166BQ belongs to IDT's high-speed synchronous SRAM product line, designed specifically for burst-oriented, low-latency memory subsystems in networking equipment, base stations, and real-time control systems.

FAQ

What is the maximum operating frequency and corresponding access time for the 71V67603S166BQ?

The 71V67603S166BQ is rated for 166MHz operation with a guaranteed clock-to-data access time (tCD) of 3.5ns. This specification applies under commercial conditions (0°C to +70°C) with VDD and VDDQ at 3.3V ±5%. The device also supports 150MHz (3.8ns) and 133MHz (4.2ns) modes for design margin or thermal derating.

Does the 71V67603S166BQ support both 256K × 36 and 512K × 18 configurations?

Yes, the 71V67603S166BQ supports both organizations. The 256K × 36 mode uses all 36 data bits (I/O0–I/O31 + I/OP1–I/OP4) and addresses A0–A17. The 512K × 18 mode repurposes I/O16–I/O31 and I/OP1–I/OP4 as address bits A18–A20, reducing data width to 18 bits. Pin configuration differs between modes - refer to PKG100 drawings on pages 5–6 of the datasheet.

How does the LBO pin affect burst addressing behavior in the 71V67603S166BQ?

The LBO pin selects burst address sequence: when pulled LOW (VSS), the 71V67603S166BQ executes linear burst (00→01→10→11); when pulled HIGH (VDD), it executes interleaved burst (00→01→11→10). LBO is asynchronous and static - it must remain stable during burst operation. This feature aligns with processor-specific cache line ordering requirements.

What is the function of the ZZ pin, and what power savings does it provide?

The ZZ pin places the 71V67603S166BQ into full sleep mode when driven HIGH. In this state, internal clocks are gated and supply current drops to ≤70µA (IZZ), representing >80% reduction versus CMOS standby (ISB1 = 50mA). Data retention is guaranteed, and no recovery delay is needed upon exit - the device resumes operation on the next valid CLK edge.

Can the 71V67603S166BQ perform byte-level writes, and how are they enabled?

Yes, the 71V67603S166BQ supports byte-level writes using BWE (byte write enable) and BW1–BW4 (individual byte write selects). When BWE is LOW, active BWx signals enable corresponding 9-bit lanes: BW1 → I/O0–I/O7 + I/OP1, BW2 → I/O8–I/O15 + I/OP2, etc. All outputs are disabled during byte writes to prevent bus contention.