Renesas 71V65603S133BQ

Overview

71V65603S133BQ from Renesas Electronics is a 256K × 36-bit (9 Mbit), 3.3V synchronous ZBT™ SRAM with zero bus turnaround, 133 MHz clock speed (7.5 ns cycle time), pipelined outputs, and 4-word burst capability. It operates across industrial temperature range (–40°C to +85°C) and supports linear/interleaved burst ordering via LBO pin. Used in high-speed packet buffering, network switch fabric, and real-time DSP memory subsystems.

For engineers reviewing the 71V65603S133BQ datasheet, 71V65603S133BQ pinout, 71V65603S133BQ application, or 71V65603S133BQ equivalent, key selection criteria include ZBT™ bus efficiency, 3.3V I/O compatibility, TQFP-100 packaging, individual byte write control (BW1–BW4), and support for pipelined read/write cycles with no dead cycles between operations.

Technical Context

The 71V65603S133BQ implements a fully synchronous, clock-edge-triggered architecture with address/control/data registers aligned to the rising edge of CLK. Its ZBT™ feature eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions without idle cycles.

It integrates an on-chip burst counter, selectable linear or interleaved burst sequence via static LBO input, and internally synchronized output buffer enable-removing external OE timing constraints. Three chip enables (CE1, CE2, CE2) support depth expansion, while ZZ enables asynchronous sleep mode for power reduction.

Key Specifications

Pinout & Package

Packaged in JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, lead-free and RoHS-compliant. Pinout validated per Renesas datasheet revision 6.42 (Nov. 12, 2021), PKG100 configuration for 256K × 36 variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-133AXC and AS7C3256A-133JCIN, the 71V65603S133BQ offers direct TQFP-100 integration for legacy board layouts, simpler single-ended clocking, and proven interoperability with Renesas-compatible memory controllers-making it optimal for cost-sensitive, volume industrial designs where footprint and routing simplicity are prioritized.

Availability

71V65603S133BQ is available at Aetrix Electronics and suitable for network packet buffering, telecom switch fabric memory, and industrial real-time controller cache requiring stable component supply, long-term lifecycle assurance, and industrial-temperature qualification.

Supply support for 71V65603S133BQ 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

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.

The 71V65603S133BQ belongs to Renesas' high-performance ZBT™ SRAM product line, engineered specifically for zero-latency memory subsystems in networking equipment, baseband units, and real-time embedded systems demanding deterministic timing and burst efficiency.

FAQ

What is the maximum operating frequency and corresponding cycle time for the 71V65603S133BQ?

The 71V65603S133BQ is rated for a maximum clock frequency of 133 MHz, corresponding to a 7.5 ns clock cycle time. This specification is guaranteed over the full industrial temperature range (–40°C to +85°C) and 3.3 V ±5% supply conditions. The device achieves 3.8 ns clock-to-data access (tCD) at 150 MHz under optimized test conditions, but 133 MHz is the validated maximum for production operation with margin.

Does the 71V65603S133BQ support both linear and interleaved burst modes, and how is the selection made?

Yes, the 71V65603S133BQ supports both linear and interleaved 4-word burst sequences. Selection is controlled by the static LBO (Linear Burst Order) pin: when LBO is driven low (VSS), linear burst order is active; when LBO is driven high (VDD), interleaved burst order is selected. The LBO state must remain stable during device operation and is sampled asynchronously-no clock required for configuration.

How does the ZBT™ feature of the 71V65603S133BQ improve system-level bus efficiency?

The ZBT™ (Zero Bus Turnaround) feature in the 71V65603S133BQ eliminates mandatory idle cycles between consecutive read and write operations. Unlike conventional SSRAMs requiring bus turnaround time, the 71V65603S133BQ permits immediate transition from write to read (or vice versa) within the same clock domain-achieving 100% bus utilization in burst sequences and reducing average memory access latency by up to 2.5 cycles per transaction.

What are the voltage requirements for VDD and VDDQ on the 71V65603S133BQ, and are they independently regulated?

The 71V65603S133BQ requires VDD = 3.3 V ±5% for core logic and VDDQ = 3.3 V ±5% for I/O drivers. These supplies are electrically separate and must be independently decoupled, though they may share a common regulator if ripple and transient response meet Renesas' noise specifications (≤50 mV peak-to-peak). VDDQ must never exceed VDD + 0.3 V, and both rails must ramp monotonically during power-up.

Can the 71V65603S133BQ be used in depth-expanded configurations, and how many chip enables does it provide?

Yes, the 71V65603S133BQ supports depth expansion using three dedicated chip enable inputs: CE1 and CE2 (active-low), and CE2 (active-high). This triple-CE architecture allows flexible bank selection and hierarchical enable control-enabling scalable memory subsystems up to 18 Mbit (two 9-Mbit devices) or beyond with external decode logic. Deselect occurs in two clock cycles, ensuring clean bus release before next access.