Renesas 71V65703S85BG

Overview

71V65703S85BG from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM organized as 256K × 36 bits (9.44 Mbit), featuring zero bus turnaround, 100 MHz operation (7.5 ns clock-to-data access), flow-through outputs, and 4-word burst capability. It serves as high-speed buffer/cache memory in networking switches, packet processors, and FPGA-based data path acceleration where deterministic latency and dead-cycle elimination are critical.

For engineers reviewing the 71V65703S85BG datasheet, 71V65703S85BG pinout, 71V65703S85BG application, or 71V65703S85BG equivalent, key selection criteria include ZBT™ burst timing compliance, TQFP-100 package compatibility, industrial temperature support (–40°C to +85°C), and byte-write enable (BW1–BW4) control for partial-word writes in multi-protocol interface buffers.

Technical Context

The 71V65703S85BG implements a synchronous, clocked architecture with registered address/control inputs and flow-through (unregistered) data outputs. Its on-chip burst counter advances on ADV/LD = HIGH, supporting linear or interleaved sequences selected by LBO, and eliminates bus turnaround delay between read/write transitions via ZBT™ protocol.

It features three chip enables (CE1, CE2 active-low; CE2 active-high) for depth expansion, asynchronous OE and ZZ controls, and separate VDD (core) and VDDQ (I/O) supplies. All synchronous operations are edge-triggered on CLK rising edge, with CEN enabling full clock gating for power management without state loss.

Key Specifications

Pinout & Package

71V65703S85BG is packaged in a 100-pin plastic thin quad flatpack (TQFP), JEDEC MO-145, 14 mm × 20 mm body, 0.5 mm lead pitch. Pin 1 is marked by a dot or beveled corner at top-left when viewed top-down with pins facing outward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1373KV18 and AS7C3256B, the 71V65703S85BG uniquely delivers 256K × 36 organization in TQFP-100 with ZBT™, industrial temperature, and integrated burst counter - making it irreplaceable for legacy or space-constrained 36-bit data path designs requiring guaranteed turnaround-free operation.

Availability

71V65703S85BG is available at Aetrix Electronics and suitable for high-speed packet buffering, network switch data path acceleration, and FPGA-based protocol offload applications requiring stable component supply, long-term lifecycle support, and industrial temperature qualification.

Supply support for 71V65703S85BG 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 71V65703S85BG belongs to IDT's ZBT™ SRAM product line, designed specifically for zero-latency, high-throughput data buffering in networking and real-time embedded systems where bus efficiency and deterministic timing are paramount.

FAQ

What is the maximum operating frequency and corresponding access time for the 71V65703S85BG?

The 71V65703S85BG operates at up to 100 MHz with a guaranteed clock-to-data access time (tCD) of 7.5 ns. This specification is measured under industrial temperature conditions (–40°C to +85°C) and 3.3 V ±5% supply, ensuring deterministic performance in real-world deployed systems. The 71V65703S85BG achieves this timing without requiring external wait-state insertion.

Does the 71V65703S85BG support both linear and interleaved burst sequences, and how is the mode selected?

Yes, the 71V65703S85BG supports both linear and interleaved 4-word burst sequences. The mode is selected by the static LBO (Linear/Interleaved Burst Order) input: LBO = LOW configures linear order (A0, A0+1, A0+2, A0+3); LBO = HIGH configures interleaved order (A0, A0+2, A0+1, A0+3). LBO must remain stable during burst operation and can be hardwired or controlled by system logic.

How does the ZBTTM (Zero Bus Turnaround) feature function in the 71V65703S85BG?

ZBTTM in the 71V65703S85BG eliminates dead cycles between consecutive read and write operations by allowing immediate bus direction reversal. When a read burst completes and a write burst begins on the next cycle, no idle clock period is required - the device internally manages bus contention and timing handoff. This is implemented via dedicated control logic and flow-through outputs, not external bus arbitration.

What are the power supply requirements for the 71V65703S85BG, and are VDD and VDDQ interchangeable?

The 71V65703S85BG requires two independent 3.3 V supplies: VDD (core logic, 3.3 V ±5%) and VDDQ (I/O drivers, 3.3 V ±5%). They are not interchangeable - VDD powers internal registers and control logic; VDDQ powers the output drivers and input receivers. Separating them allows independent noise filtering and improves signal integrity on the 36-bit data bus.

Can the 71V65703S85BG operate in low-power mode, and how is it activated?

Yes, the 71V65703S85BG supports low-power sleep mode via the asynchronous ZZ input. When ZZ is driven HIGH, the internal clock is gated, reducing ICC to standby current while retaining full data integrity in memory cells. Sleep mode exits automatically on ZZ transition to LOW, with data available after one clock cycle - no initialization or refresh is needed.