Renesas 71V35761SA166BG8

Overview

71V35761SA166BG8 from IDT is a 128K × 36-bit, 3.3V synchronous SRAM with pipelined outputs, burst counter, and single-cycle deselect. It supports 166MHz operation (3.5ns clock access time), operates over –40°C to +85°C, features JTAG boundary scan (IEEE 1149.1), and uses a 165-ball fine-pitch BGA (fBGA) package. It serves as high-speed cache or buffer memory in telecom switching fabric and network processor subsystems.

For engineers reviewing the 71V35761SA166BG8 datasheet, 71V35761SA166BG8 pinout, 71V35761SA166BG8 application, or 71V35761SA166BG8 equivalent, key selection considerations include burst mode configuration (LBO), sleep mode control (ZZ), byte-write granularity (BW1–BW4), JTAG test interface availability, and industrial-temperature timing compliance at 166MHz.

Technical Context

This SRAM implements a synchronous, clock-driven architecture with registered address, data, and control paths. Its internal burst address counter enables four-word sequential reads/writes per address latch, selectable between linear and interleaved order via the asynchronous LBO pin. Pipelined output registers deliver first data one clock cycle after address assertion.

The device integrates dual power domains (VDD = 3.3V core, VDDQ = 3.3V I/O), supports global and byte-level write control (GW/BWE/BWx), and includes asynchronous sleep mode (ZZ) and optional IEEE 1149.1 JTAG for boundary scan - all implemented in a high-performance CMOS process.

Key Specifications

Pinout & Package

71V35761SA166BG8 is packaged in a 165-ball fine-pitch BGA (fBGA), JEDEC-compliant, with 0.8 mm ball pitch and 13 mm × 15 mm body size. Pin functions are defined per the BQG165 package drawing (Rev. May 18, 2020).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-166BZI and AS7C3256P-166JCIN, the 71V35761SA166BG8 uniquely combines JTAG testability, industrial-temperature operation, and active sleep mode in a fine-pitch fBGA - making it optimal for high-reliability, test-access-limited telecom and defense platforms.

Availability

71V35761SA166BG8 is available at Aetrix Electronics and suitable for telecom switching fabric, network processor buffering, and radar signal processing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 71V35761SA166BG8 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 timing, memory interface, and RF solutions for communications and computing infrastructure.

The 71V35761SA166BG8 belongs to IDT's high-speed synchronous SRAM product line, designed specifically for low-latency, burst-capable memory subsystems in network processors, baseband units, and real-time DSP applications.

FAQ

What is the maximum operating frequency and corresponding access time for the 71V35761SA166BG8?

The 71V35761SA166BG8 is rated for 166 MHz operation with a guaranteed clock-to-data access time (tCD) of 3.5 ns. This specification applies across the full industrial temperature range (–40°C to +85°C) and under worst-case voltage conditions (VDD/VDDQ = 3.135 V). The device also supports faster 183 MHz and 200 MHz speeds in commercial temperature grades, but 71V35761SA166BG8 is specifically characterized and screened for 166 MHz industrial use.

Does the 71V35761SA166BG8 support both linear and interleaved burst modes, and how is the selection made?

Yes, the 71V35761SA166BG8 supports both linear and interleaved burst sequences via the LBO (Linear/Interleaved Burst Order) pin. When LBO is driven LOW, the device executes linear burst addressing (00→01→10→11); when HIGH, it uses interleaved order (00→01→11→10). LBO is an asynchronous static input and must remain stable during burst operation - changing it mid-burst may cause undefined address sequencing in the 71V35761SA166BG8.

What JTAG functionality does the 71V35761SA166BG8 provide, and which pins are dedicated to it?

The 71V35761SA166BG8 implements full IEEE 1149.1 boundary scan with dedicated TMS, TDI, TCK, TDO, and optional TRST pins. These appear on balls U1–U6 in the 165-ball fBGA package. All JTAG pins feature internal pull-ups, and TRST is optional - if unused, it may be left floating. This JTAG interface enables board-level interconnect testing and in-system programming verification for the 71V35761SA166BG8 in complex telecom assemblies.

How does the sleep mode (ZZ) function in the 71V35761SA166BG8, and what is its power impact?

In the 71V35761SA166BG8, asserting ZZ HIGH places the device into full sleep mode, gating the internal clock and reducing supply current to ≤35 mA (ISB1) while guaranteeing data retention. Recovery requires tZZR ≥100 ns after ZZ returns LOW before valid operations resume. This mode is especially valuable in intermittently active systems like remote radio units, where the 71V35761SA166BG8 can cut dynamic power by >70% during idle intervals.

What are the key differences between the 71V35761SA166BG8 and the non-JTAG 'S' version (e.g., 71V35761S166BG8)?

The 71V35761SA166BG8 includes full IEEE 1149.1 JTAG boundary scan capability, whereas the 'S' suffix variant omits TMS/TDI/TCK/TDO/TRST functionality. In the 165-ball fBGA, JTAG pins replace NC functions present in the 'S' version. Both share identical memory organization, timing, power specs, and industrial temperature rating - the 71V35761SA166BG8 adds testability at no performance or reliability trade-off.