Renesas 71V3556SA133BQGI

Overview

71V3556SA133BQGI from IDT (now Renesas) is a 3.3V synchronous ZBT™ SRAM with 128K × 36-bit organization (4.5 Mbit), 133 MHz maximum clock frequency, 3.5 ns clock-to-data access time, zero bus turnaround architecture, and pipelined outputs. It serves as high-speed buffer/cache memory in network packet processors and telecom line cards requiring deterministic burst read/write with no dead cycles.

For engineers reviewing the 71V3556SA133BQGI datasheet, 71V3556SA133BQGI pinout, 71V3556SA133BQGI application, or 71V3556SA133BQGI equivalent, key selection criteria include ZBT™ timing compliance, 100-pin TQFP package compatibility, industrial temperature support (–40°C to +85°C), JTAG boundary scan capability, and 4-word interleaved/linear burst mode operation.

Technical Context

The 71V3556SA133BQGI implements a fully synchronous, positive-edge-triggered architecture with registered address, control, and data paths. Its ZBT™ feature eliminates bus turnaround latency by enabling immediate read-after-write or write-after-read transitions without idle cycles.

It integrates an on-chip 4-word burst counter controlled by ADV/LD and LBO pins, supports individual byte write via BW1–BW4, and includes optional IEEE 1149.1 JTAG boundary scan (TMS/TDI/TCK/TDO/TRST) for testability - all operating at 3.3V core and I/O supply with ±5% tolerance.

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, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV33-133AXC and AS7C33128PFSIG-133, the 71V3556SA133BQGI delivers true zero-turnaround operation, integrated 4-word burst logic, and IEEE 1149.1 testability - making it uniquely suited for deterministic, high-throughput, testable embedded memory subsystems.

Availability

71V3556SA133BQGI is available at Aetrix Electronics and suitable for telecom infrastructure, network packet processing, and industrial embedded systems requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for 71V3556SA133BQGI 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 interface, and RF solutions for communications and computing markets.

The 71V3556SA133BQGI belongs to IDT's ZBT™ SRAM product line, engineered specifically for zero-latency, burst-oriented memory subsystems in networking ASICs, telecom line cards, and real-time signal processing platforms.

FAQ

What is the memory organization and total capacity of the 71V3556SA133BQGI?

The 71V3556SA133BQGI is organized as 128K × 36 bits, delivering a total capacity of 4,718,592 bits (4.5 Mbit). This configuration supports 32-bit data paths plus 4-bit parity or ECC, making it ideal for high-integrity applications such as telecom control plane memory and packet buffering where data integrity and bandwidth are critical. The device operates exclusively in this 128K × 36 mode - no 256K × 18 reconfiguration is supported in the SA variant.

Does the 71V3556SA133BQGI support JTAG boundary scan, and which pins are used?

Yes, the 71V3556SA133BQGI supports IEEE 1149.1-compliant JTAG boundary scan. Pins TMS, TDI, TCK, TDO, and optional TRST are assigned to JTAG functionality. On the 100-pin TQFP package (BQGI suffix), these signals are implemented on dedicated pins - TMS (Pin 89), TDI (Pin 90), TCK (Pin 91), TDO (Pin 92), and TRST (Pin 93) - and are functional only when the SA version is selected. TRST is optional and may be left floating if unused.

How does the ZBTTM feature eliminate dead cycles in the 71V3556SA133BQGI?

The ZBTTM (Zero Bus Turnaround) feature in the 71V3556SA133BQGI removes idle cycles between consecutive read and write operations by overlapping bus direction control internally. Unlike conventional SRAMs that require explicit turnaround time (typically 1–2 clocks), the 71V3556SA133BQGI allows a write cycle to immediately follow a read (or vice versa) without inserting wait states - achieving continuous 133 MT/s throughput. This is implemented via internal bus arbitration logic synchronized to the rising CLK edge.

What are the voltage requirements and power supply separation for the 71V3556SA133BQGI?

The 71V3556SA133BQGI requires two independent 3.3 V supplies: VDD (core logic, 3.3 V ±5%) and VDDQ (I/O drivers, also 3.3 V ±5%). VSS serves as common ground. Separation prevents I/O switching noise from affecting core timing. Both supplies must ramp monotonically during power-up; no sequencing is required, but no I/O pin voltage may exceed VDDQ during ramp. Absolute max ratings specify –0.5 V to VDDQ +0.5 V on I/O pins.

Can the 71V3556SA133BQGI operate in sleep mode, and how is it enabled?

Yes, the 71V3556SA133BQGI supports low-power sleep mode via the ZZ pin. When ZZ is driven HIGH (VIH ≥ 2.0 V), the internal clock is gated and the device enters its lowest power state while maintaining full data retention. ZZ is a synchronous input with internal pulldown; it must be held HIGH for at least one CLK cycle to activate sleep. In sleep mode, all outputs go high-impedance and dynamic power drops significantly - critical for power-constrained telecom modules.