Renesas 71V546S133PFG

Overview

71V546S133PFG from Integrated Device Technology is a 3.3V, 128K × 36-bit (4.5 Mbit) synchronous SRAM with ZBT™ (Zero Bus Turnaround) architecture, pipelined outputs, and 4-word burst capability. It operates at 133 MHz (7.5 ns cycle time), delivers 4.2 ns clock-to-data access, and supports interleaved or linear burst ordering via the LBO pin. It is used in high-speed packet buffering and network switch fabric control planes.

For engineers reviewing the 71V546S133PFG datasheet, 71V546S133PFG pinout, 71V546S133PFG application, or 71V546S133PFG equivalent, key selection criteria include ZBT™ bus turnaround elimination, synchronous 3.3V operation with CEN/ADV/LD control logic, 100-pin TQFP packaging, and industrial temperature support (–40°C to +85°C).

Technical Context

The 71V546S133PFG implements a fully pipelined synchronous interface with address, control, and data registers triggered on the rising edge of CLK. All inputs except OE are synchronous, and internal burst counter advancement is controlled by ADV/LD level sampling - low loads new address, high increments counter.

ZBT™ functionality eliminates dead cycles between read/write transitions by decoupling bus direction control from data transfer timing. The device uses three chip enables (CE1, CE2 active-low; CE2 active-high) for depth expansion and supports individual byte write (BW1–BW4) with 9-bit granularity per byte group.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body size, with exposed pad not required for thermal performance per datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1355BV18-133BZI and AS7C33128PFSI-133, the 71V546S133PFG uniquely combines true ZBT™ operation, 100-pin TQFP compatibility, and programmable burst ordering - making it optimal for retrofitting legacy IDT-based switch fabric designs without layout changes.

Availability

71V546S133PFG is available at Aetrix Electronics and suitable for network packet buffering, switch fabric control memory, and telecom line card memory requiring stable component supply and long-term industrial temperature support.

Supply support for 71V546S133PFG 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

Integrated Device Technology (IDT), now part of Renesas Electronics, specializes in high-performance timing, memory interface, and RF solutions for communications and computing infrastructure.

The IDT71V546 product line was designed specifically for high-speed, low-latency data buffering in networking ASIC interfaces - emphasizing ZBT™ efficiency, burst predictability, and industrial reliability.

FAQ

What does the "S133" suffix in 71V546S133PFG indicate?

The "S133" suffix denotes the speed grade: 133 MHz maximum operating frequency (7.5 ns clock cycle). This is confirmed in the AC Electrical Characteristics table (tCYC = 7.5 ns, fMAX = 133 MHz) and distinguishes it from slower variants like 71V546S100. The 71V546S133PFG is fully specified and tested to operate reliably at this rate across industrial temperature ranges.

Does the 71V546S133PFG require external OE control during normal operation?

No - the 71V546S133PFG does not require active OE control. Its internally synchronized registered outputs eliminate the need to manage OE timing; OE can be tied low permanently. This simplifies interface design and removes a critical timing constraint from the system bus, as stated in the Features section and Pin Definitions table.

How does the ZBT™ feature improve system performance compared to standard synchronous SRAMs?

ZBT™ eliminates dead cycles between read and write operations by allowing immediate bus direction reversal without wait states. In the 71V546S133PFG, this enables back-to-back R/W transitions with zero turnaround penalty - verified in the Synchronous Truth Table and Timing Waveforms - increasing effective bandwidth in mixed-access applications like packet buffering by up to 30%.

Can the 71V546S133PFG be used in linear burst mode only, or is interleaved mode mandatory?

The 71V546S133PFG supports both linear and interleaved burst modes, selected dynamically via the LBO pin: LOW configures linear (A0–A1 increment sequentially), HIGH selects interleaved (A0–A1 follow cache-line pattern). Both modes are fully characterized and documented in Tables 9 and 10, giving designers flexibility for different memory access profiles.

What is the function of the three chip enable pins (CE1, CE2, CE2) on the 71V546S133PFG?

The 71V546S133PFG uses CE1 and CE2 as active-low enables and CE2 as an active-high enable. All three must be asserted (CE1 = L, CE2 = L, CE2 = H) to select the device. This arrangement allows flexible depth expansion - e.g., using CE1/CE2 for row decoding and CE2 for bank selection - without external logic, as defined in the Pin Definitions and Truth Table.