Renesas 71V25761S166PFG8

Overview

71V25761S166PFG8 from Renesas Electronics is a 128K × 36-bit, 3.3V synchronous SRAM with pipelined outputs, burst counter, and single-cycle deselect. It operates at 166MHz (3.5ns clock access time), supports 2.5V I/O, and features linear/interleaved burst mode via LBO input. Used in high-speed cache and buffer subsystems for network processors and telecom line cards.

For engineers reviewing the 71V25761S166PFG8 datasheet, 71V25761S166PFG8 pinout, 71V25761S166PFG8 application, or 71V25761S166PFG8 equivalent, this page delivers verified timing parameters, JEDEC-standard TQFP-100 package mapping, burst-mode control logic, power-down behavior under ZZ, and real-world use cases in synchronous memory subsystems requiring deterministic latency and multi-byte burst throughput.

Technical Context

The 71V25761S166PFG8 implements a synchronous interface with registered address, data, and control inputs triggered on the rising edge of CLK. Its internal burst address counter generates four sequential addresses per initial access, with order determined by LBO state (linear or interleaved) and advanced via ADV signal.

Burst writes are supported through global write (GW) or byte-write enables (BWE + BW1–BW4), while self-timed write cycles eliminate external write pulse generation. Pipelined output staging delivers first data one clock cycle after address latch, enabling sustained 166MHz read throughput without wait states.

Key Specifications

Pinout & Package

71V25761S166PFG8 is packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body size, with 0.5 mm pitch and exposed thermal pad (not electrically connected). Pin 1 is marked by a dot or beveled corner; pin numbering follows standard counter-clockwise convention from top-left.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1371DV33-166AXC and AS7C312836B-166BIN, the 71V25761S166PFG8 uniquely integrates configurable burst sequencing (LBO), autonomous burst advance (ADV), and hardware sleep control (ZZ), making it optimal for cache-coherent and power-constrained synchronous memory subsystems.

Availability

71V25761S166PFG8 is available at Aetrix Electronics and suitable for network processor cache buffers, telecom packet buffers, and DSP co-processor local memory requiring stable component supply across commercial temperature range and long-term production cycles.

Supply support for 71V25761S166PFG8 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, infrastructure, and IoT applications.

The 71V25761S166PFG8 belongs to Renesas' high-speed synchronous SRAM product line, designed specifically for deterministic-latency, burst-capable memory subsystems in networking, telecommunications, and real-time embedded systems.

FAQ

What is the maximum clock frequency supported by the 71V25761S166PFG8?

The 71V25761S166PFG8 is rated for 166 MHz operation, corresponding to a 6 ns clock cycle time and guaranteed 3.5 ns clock-to-data (tCD) access time. This speed is validated across the commercial temperature range (0°C to +70°C) with VDD = 3.3 V ±5% and VDDQ = 2.5 V ±5%. The 71V25761S166PFG8 does not support 183 MHz or 200 MHz operation - those speeds require distinct orderable variants (e.g., 71V25761S183PFG8).

How does the LBO pin affect burst addressing in the 71V25761S166PFG8?

The LBO (Linear/Interleaved Burst Order) pin on the 71V25761S166PFG8 statically selects burst sequence: LBO = LOW enables linear addressing (00→01→10→11), while LBO = HIGH enables interleaved addressing (00→01→11→10). This configuration must be set before device initialization and held static during operation. The 71V25761S166PFG8 uses this input to align burst output with cache line or DRAM row access patterns without external logic.

Does the 71V25761S166PFG8 support partial-word writes, and how are they implemented?

Yes, the 71V25761S166PFG8 supports partial-word writes via its byte-write architecture. Four 9-bit byte groups (BW1–BW4) control I/O0–7+I/OP1, I/O8–15+I/OP2, I/O16–23+I/OP3, and I/O24–31+I/OP4 respectively. When BWE = LOW, active BWx signals enable writing only the selected bytes; unselected bytes retain prior data. This eliminates need for read-modify-write cycles in the 71V25761S166PFG8.

What is the function of the ZZ pin on the 71V25761S166PFG8, and what power savings does it provide?

The ZZ (Sleep Mode) pin on the 71V25761S166PFG8 is an asynchronous input that, when driven HIGH, gates the internal clock and places the device in full sleep mode. In this state, supply current drops to 30 mA (IZZ), while data retention is guaranteed. This feature enables significant power reduction during idle periods in systems like packet buffers or PLC loggers, where the 71V25761S166PFG8 remains powered but inactive.

Is the 71V25761S166PFG8 pin-compatible with other members of the 71V25761 family?

Yes, the 71V25761S166PFG8 shares identical pinout and package (100-pin TQFP) with all speed grades in the 71V25761SxxxPFGx series, including 183 MHz and 200 MHz variants. Electrical characteristics and timing parameters differ by speed grade, but PCB layout, power delivery, and signal routing remain interchangeable - allowing field-upgradeable performance scaling without board redesign for the 71V25761S166PFG8.