Renesas 71V65903S85BQG

Overview

71V65903S85BQG from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM organized as 512K × 18 (9,437,184-bit), supporting 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 memory in network packet processors and telecom line cards requiring deterministic burst transfers.

For engineers reviewing the 71V65903S85BQG datasheet, 71V65903S85BQG pinout, 71V65903S85BQG application, or 71V65903S85BQG equivalent, key selection criteria include its 4-word interleaved/linear burst capability, individual byte write control (BW1–BW2), asynchronous ZZ sleep mode, and JEDEC-standard 100-pin TQFP package with industrial temperature support (–40°C to +85°C).

Technical Context

The 71V65903S85BQG implements a synchronous architecture with registered address/control inputs triggered on the rising edge of CLK, and a flow-through output path (no output register). Its internal burst counter advances on ADV/LD = HIGH, with burst order selected by static LBO pin (LOW = linear, HIGH = interleaved).

It features three chip enables (CE1, CE2 active-low; CE2 active-high) for depth expansion, single R/W control, and internally synchronized OE elimination-removing external timing constraints on output enable. Power-down is managed via asynchronous ZZ input, guaranteeing data retention during sleep mode.

Key Specifications

Pinout & Package

71V65903S85BQG is packaged in a JEDEC-standard 100-pin TQFP (PKG100), 14 mm × 20 mm body, with 0.5 mm pitch. Pin assignments are optimized for signal integrity in high-speed memory buses, including dedicated VDDQ/VSS pairs adjacent to I/O banks and distributed power/ground pins.

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 71V65903S85BQG delivers superior throughput in burst-oriented systems due to its integrated burst counter and zero-turnaround architecture-reducing controller complexity and maximizing usable bandwidth per clock cycle.

Availability

71V65903S85BQG is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, baseband processing cache, and industrial PLC data logging requiring stable component supply across extended product lifecycles.

Supply support for 71V65903S85BQG 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 timing, memory interface, RF, and high-performance interconnect solutions for communications and computing infrastructure.

The 71V65903S85BQG belongs to IDT's ZBT™ SRAM product line, designed specifically for high-speed networking, telecom, and military/aerospace systems demanding deterministic latency, burst efficiency, and industrial-grade reliability.

FAQ

What memory organization does the 71V65903S85BQG support?

The 71V65903S85BQG is configured as 512K × 18 (9,437,184 bits), optimized for systems requiring wide data paths with moderate depth-such as packet header buffers and descriptor tables. It does not support the 256K × 36 configuration; that variant is implemented in the 71V65703 family member. The 71V65903S85BQG uses address pins A0–A18 exclusively for full 512K addressing.

Does the 71V65903S85BQG support both linear and interleaved burst modes?

Yes, the 71V65903S85BQG supports both burst orders via the LBO (Linear/Interleaved Burst Order) pin: LBO = LOW selects linear sequence (A0, A1, A2, A3), and LBO = HIGH selects interleaved (A0, A2, A1, A3). This flexibility allows alignment with different memory controller architectures-e.g., linear for simple DMA engines and interleaved for cache-line–aligned fetch units. The 71V65903S85BQG's burst counter advances synchronously on ADV/LD = HIGH.

How does the 71V65903S85BQG handle power-down and data retention?

The 71V65903S85BQG enters low-power sleep mode when ZZ is driven HIGH asynchronously. In this state, internal clocks are gated, core logic is suspended, and standby current drops below 100 µA-while guaranteed data retention is maintained across the full industrial temperature range (–40°C to +85°C). VDD and VDDQ must remain within specification (3.3 V ±5%) during sleep; no external refresh or backup power is required for the 71V65903S85BQG to retain memory contents.

What is the function of the ADV/LD pin on the 71V65903S85BQG?

The ADV/LD pin on the 71V65903S85BQG performs dual functions: when sampled LOW at the rising CLK edge (with chip enabled), it loads a new external address into the internal address register; when sampled HIGH, it advances the internal burst counter to generate the next sequential address. This eliminates the need for external burst address generation logic and enables seamless 4-word bursts with minimal controller intervention-making the 71V65903S85BQG especially efficient in DMA-driven or packet-processing applications.

Can the 71V65903S85BQG be used with a 2.5V or 1.8V I/O interface?

No, the 71V65903S85BQG requires VDDQ = 3.3 V ±5% for I/O operation and is not 2.5V- or 1.8V-tolerant. Its input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V) and output drive strength are specified only for 3.3V signaling. Interfacing with lower-voltage logic requires level-shifting circuitry. The 71V65903S85BQG's VDDQ pins must be decoupled independently from VDD to maintain signal integrity and meet AC timing specifications at 100 MHz.