Renesas 71V3556SA100BQGI8

Overview

71V3556SA100BQGI8 from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit organization (4.5 Mbit), 100 MHz clock speed, 3.5 ns clock-to-data access time, zero bus turnaround architecture, and pipelined outputs in a 100-pin TQFP package. It serves as high-speed buffer memory in network packet processors and telecom line cards requiring deterministic read/write interleaving without dead cycles.

For engineers reviewing the 71V3556SA100BQGI8 datasheet, 71V3556SA100BQGI8 pinout, 71V3556SA100BQGI8 application, or 71V3556SA100BQGI8 equivalent, key selection criteria include burst mode support (linear/interleaved), individual byte write control (BW1–BW4), JTAG boundary scan compliance (IEEE 1149.1), and industrial temperature operation (–40°C to +85°C).

Technical Context

The 71V3556SA100BQGI8 implements a fully synchronous, positive-edge-triggered architecture with registered address, data, and control inputs. Its ZBT™ core eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions using an internal burst counter and ADV/LD-controlled address sequencing.

It integrates pipelined input/output registers, asynchronous OE for output tri-state control, and optional IEEE 1149.1 JTAG test interface with TMS/TDI/TCK/TDO/TRST pins. The device supports 4-word burst transfers and individual byte write enables-critical for cache coherency and partial-word updates in high-throughput data paths.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 100-pin plastic thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 64 supports ZZ (sleep mode) on latest die revision; pins 14/16/66 tolerate VIH-level voltage without direct VDD connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356KV18-100BZXI and AS7C33128PFSIG-100, the 71V3556SA100BQGI8 uniquely delivers zero bus turnaround, JTAG testability, and full x36 burst support-making it irreplaceable in latency-critical telecom and packet-processing designs.

Availability

71V3556SA100BQGI8 is available at Aetrix Electronics and suitable for network packet processors, telecom line cards, and baseband processors requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for 71V3556SA100BQGI8 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 infrastructure.

The 71V3556SA100BQGI8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency memory subsystems in high-speed networking, wireless infrastructure, and real-time signal processing applications.

FAQ

What is the memory configuration and total capacity of the 71V3556SA100BQGI8?

The 71V3556SA100BQGI8 is configured as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This organization supports 36-bit parallel data paths commonly used in network processors and DSP interfaces, and is distinct from the 256K × 18 variant offered in the same family.

Does the 71V3556SA100BQGI8 support JTAG boundary scan, and which pins are used?

Yes, the 71V3556SA100BQGI8 supports IEEE 1149.1-compliant JTAG boundary scan. Pins TMS, TDI, TCK, TDO, and optional TRST are dedicated to this function and appear on the 100-pin TQFP package. TRST has an internal pullup and may be left floating if unused.

How does the ZBT™ feature eliminate bus turnaround cycles in the 71V3556SA100BQGI8?

The ZBT™ feature in the 71V3556SA100BQGI8 removes dead cycles between read and write operations by using an internal burst counter and synchronized control logic. When ADV/LD advances the counter, the next access occurs immediately-no clock cycle is wasted waiting for bus direction settling, enabling true back-to-back transactions.

What is the role of the ADV/LD and LBO pins in burst operation of the 71V3556SA100BQGI8?

In the 71V3556SA100BQGI8, ADV/LD loads a new external address when LOW or increments the internal burst counter when HIGH. LBO selects burst order: LOW enables linear addressing (0,1,2,3), HIGH enables interleaved (0,2,3,1)-matching common CPU cache line layouts and optimizing sequential throughput.

Can the 71V3556SA100BQGI8 operate in low-power mode, and how is it controlled?

Yes, the 71V3556SA100BQGI8 supports low-power sleep mode via the synchronous ZZ pin. When ZZ is driven HIGH, the internal clock is gated and core power drops to minimum while retaining memory contents. This mode is fully compatible with industrial temperature operation and requires no external circuitry.