Renesas 71V2546S133BG

Overview

71V2546S133BG from IDT (now Renesas) is a 128K × 36-bit (4.5 Mbit), 3.3V synchronous ZBT™ SRAM with 2.5V I/O, pipelined outputs, and zero-bus-turnaround architecture. It delivers 133 MHz operation (7.5 ns clock-to-data access), supports 4-word linear/interleaved burst modes via internal counter, and features individual byte write control (BW1–BW4), three chip enables (CE1/CE2/CE2), and industrial temperature range (–40°C to +85°C). It is used in high-speed packet buffering and network switch fabric memory subsystems.

For engineers reviewing the 71V2546S133BG datasheet, 71V2546S133BG pinout, 71V2546S133BG application, or 71V2546S133BG equivalent, key selection considerations include ZBT timing compliance, TQFP-100 vs. BGA-119 package compatibility, 2.5V I/O voltage domain isolation, burst sequence control via LBO, and CE/R/W/ADV/LD signal timing coordination for pipelined read/write cycles.

Technical Context

This device implements a fully synchronous, clock-edge-triggered architecture where address, data, and control signals are registered on the rising edge of CLK. All operations-including burst initiation, counter increment, and byte-write enable-are synchronized to CLK, eliminating asynchronous timing hazards.

The ZBT™ architecture eliminates dead cycles between consecutive reads and writes by overlapping bus turnaround with the next cycle's address setup. Internally, it integrates a 4-word burst counter, pipelined output registers, and independent 2.5V I/O supply (VDDQ) decoupled from the 3.3V core (VDD), enabling mixed-voltage system interfacing.

Key Specifications

Pinout & Package

71V2546S133BG is packaged in a JEDEC-standard 119-ball grid array (BG119) with 1.0 mm ball pitch and exposed thermal pad. The package supports industrial temperature operation and provides low-inductance I/O routing for high-speed signaling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV18-133BZI and AS7C3128B-133JCIN, the 71V2546S133BG uniquely delivers zero-turnaround burst performance with minimal control logic-enabling higher sustained bandwidth in single-port, latency-critical applications like packet buffering without QDR complexity or standard SRAM timing penalties.

Availability

71V2546S133BG is available at Aetrix Electronics and suitable for network infrastructure, telecom switching, and industrial automation applications requiring stable component supply, long-lifecycle support, and industrial-grade temperature reliability.

Supply support for 71V2546S133BG 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 markets.

The 71V2546S133BG belongs to IDT's ZBT™ SRAM product line, engineered specifically for high-speed networking and packet-processing systems where deterministic latency, burst efficiency, and bus utilization are critical design constraints.

FAQ

What is the maximum operating frequency of the 71V2546S133BG?

The 71V2546S133BG is rated for 133 MHz operation, corresponding to a 7.5 ns clock-to-data access time. This specification is guaranteed over the full industrial temperature range (–40°C to +85°C) and under recommended 3.3V ±5% VDD and 2.5V ±5% VDDQ supply conditions. Performance is validated using JEDEC-standard AC test loads and timing margins.

Does the 71V2546S133BG support both linear and interleaved burst modes?

Yes, the 71V2546S133BG supports both linear and interleaved 4-word burst sequences. The LBO (Linear/Burst Order) pin selects the mode: driven to VSS for linear addressing (A0–A16, A0–A16+1, A0–A16+2, A0–A16+3) or to VDD for interleaved addressing (A0–A16, A0–A16+8192, A0–A16+1, A0–A16+8193). This is implemented entirely in hardware with no firmware overhead.

How does the ZBTTM feature improve system performance in the 71V2546S133BG?

ZBTTM (Zero Bus Turnaround) in the 71V2546S133BG eliminates idle cycles between consecutive read and write operations. Unlike conventional SRAMs that require bus release/reacquisition, the 71V2546S133BG transitions directly from one data transfer to the next-enabling sustained 133 MHz throughput in mixed-access workloads typical of packet buffering and switch fabric applications.

What is the function of the ZZ pin on the 71V2546S133BG?

The ZZ pin on the 71V2546S133BG enables deep sleep mode. When asserted LOW (on the latest die revision), it places the device in ultra-low-power standby, reducing ICC to less than 10 µA. All I/Os enter high-impedance, and internal state is retained. Exit is synchronous to the next rising CLK edge after ZZ returns HIGH, ensuring glitch-free wake-up.

Can the 71V2546S133BG be used with a 3.3V-only system, or is the 2.5V I/O supply mandatory?

The 2.5V I/O supply (VDDQ) is mandatory for correct operation of the 71V2546S133BG. While VDD must be 3.3V ±5%, VDDQ must be independently supplied at 2.5V ±5%. This separation is fundamental to the device's I/O interface design and electrical specifications-including VIH/VIL thresholds, output drive strength, and AC timing. Using 3.3V on VDDQ violates absolute maximum ratings and risks functional failure.