Renesas 71V65903S85PFGI8

Overview

71V65903S85PFGI8 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. It implements zero bus turnaround (ZBT), burst counter logic, flow-through outputs, and individual byte write control - deployed in high-speed packet buffering, network switch fabric, and real-time DSP memory subsystems.

For engineers reviewing the 71V65903S85PFGI8 datasheet, 71V65903S85PFGI8 pinout, 71V65903S85PFGI8 application, or 71V65903S85PFGI8 equivalent, key selection criteria include ZBT timing compliance, 3.3V I/O compatibility, industrial temperature support (–40°C to +85°C), TQFP-100 packaging, and burst mode configuration via ADV/LD and LBO.

Technical Context

The 71V65903S85PFGI8 uses a synchronous CMOS architecture with registered address/control inputs and flow-through data outputs - eliminating output registers to minimize read latency. Its internal burst counter advances on ADV/LD = HIGH, supporting linear or interleaved 4-word bursts selected by the static LBO pin.

Three chip enables (CE1, CE2 active-low; CE2 active-high) enable depth expansion without external logic. Clock Enable (CEN) suspends all synchronous operations while preserving register state, and asynchronous ZZ input places the device in low-power sleep mode with guaranteed data retention.

Key Specifications

Pinout & Package

Packaged in JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pinout conforms to PKG100 footprint for 512K × 18 configuration (per datasheet drawing 5298 drw 02a).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV33-100AXC and AS7C35128PFS-10BIN, the 71V65903S85PFGI8 uniquely delivers zero bus turnaround with integrated burst addressing - reducing control logic, improving effective bandwidth in mixed-access scenarios, and lowering system-level timing margin risk.

Availability

71V65903S85PFGI8 is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, DSP algorithm scratchpad, and FPGA co-processor cache applications requiring stable component supply, long-term industrial temperature support, and JEDEC-compliant TQFP packaging.

Supply support for 71V65903S85PFGI8 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, and interface solutions for communications and computing infrastructure.

The 71V65903S85PFGI8 belongs to IDT's ZBT™ SRAM product line, designed specifically for low-latency, high-throughput memory subsystems in networking, telecom, and real-time signal processing equipment where deterministic bus turnaround and burst efficiency are critical.

FAQ

What memory organization does the 71V65903S85PFGI8 support?

The 71V65903S85PFGI8 is organized as 512K × 18 (9,437,184 bits), using 19 address lines (A0–A18) and 18 data I/O lines plus two parity pins (I/OP1, I/OP2). This x18 configuration is distinct from the 256K × 36 variant and requires dedicated pin mapping per the PKG100 512K × 18 layout.

Does the 71V65903S85PFGI8 support zero bus turnaround (ZBT) in both read and write directions?

Yes, the 71V65903S85PFGI8 supports true ZBT operation: it eliminates dead cycles between any read-to-write or write-to-read transitions. This is achieved through internal synchronization of OE and burst control, enabling immediate bus direction reversal without external wait-state insertion - a core feature confirmed in the functional description and timing tables.

How is burst mode configured on the 71V65903S85PFGI8?

Burst mode on the 71V65903S85PFGI8 is controlled by ADV/LD and LBO. ADV/LD = HIGH advances the internal counter for 4-word bursts; LBO = LOW selects linear order, LBO = HIGH selects interleaved order. The burst sequence is fixed per LBO state and cannot be changed mid-burst - verified in Tables 10 and 11 of the datasheet.

What is the role of the three chip enable pins (CE1, CE2, CE2) on the 71V65903S85PFGI8?

The 71V65903S85PFGI8 uses CE1 and CE2 as active-low enables and CE2 as an active-high enable. The device is selected only when CE1 = LOW, CE2 = LOW, and CE2 = HIGH simultaneously. Any violation initiates a one-cycle deselect - tri-stating outputs on the next clock edge - enabling simple depth expansion without glue logic.

Can the 71V65903S85PFGI8 operate in low-power mode, and how is it activated?

Yes, the 71V65903S85PFGI8 supports low-power sleep mode via the asynchronous ZZ pin. When ZZ is driven HIGH, the internal clock is gated and power consumption drops to minimum while data retention is guaranteed. This mode is independent of CEN and remains active until ZZ returns LOW - confirmed in Pin Definitions and DC Characteristics sections.