Renesas 71V3556SA150BQ

Overview

71V3556SA150BQ from IDT (now Renesas) is a 3.3V, 128K × 36-bit synchronous ZBT SRAM with Zero Bus Turnaround architecture, 150 MHz clock speed (6.67 ns cycle time), 3.5 ns clock-to-data access, pipelined outputs, and JTAG boundary scan support. It operates across industrial temperature range (–40°C to +85°C) and is used in high-bandwidth packet buffering for network switches and routers.

For engineers reviewing the 71V3556SA150BQ datasheet, 71V3556SA150BQ pinout, 71V3556SA150BQ application, or 71V3556SA150BQ equivalent, key selection criteria include ZBT bus turnaround elimination, 4-word burst capability (linear/interleaved), individual byte write control (BW1–BW4), synchronous OE-free output enable, and JEDEC-standard 165-ball fine-pitch BGA (BQ) packaging.

Technical Context

The 71V3556SA150BQ implements a fully synchronous, pipelined memory interface with address/control/data registers triggered on the positive clock edge. Its ZBT architecture eliminates dead cycles between read and write operations by overlapping bus turnaround with internal memory access.

It integrates an on-chip burst counter controlled by ADV/LD and LBO pins, supports linear or interleaved 4-word bursts, and features three chip enables (CE1, CE2, CE2) for depth expansion. Optional IEEE 1149.1 JTAG boundary scan is implemented via TMS/TDI/TCK/TDO/TRST pins, available only in BGA packages.

Key Specifications

Pinout & Package

Packaged in a JEDEC-standard 165-ball fine-pitch ball grid array (fBGA), designated BQ165/BQG165 per IDT documentation. Pin pitch is 0.8 mm; package dimensions are 13 mm × 15 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1356BV18-167BZI and AS7C33128PFSIG, the 71V3556SA150BQ uniquely delivers ZBT bus turnaround elimination, integrated 4-word burst counter, and IEEE 1149.1 JTAG - making it optimal for high-efficiency, testable, industrial-grade networking buffers.

Availability

71V3556SA150BQ is available at Aetrix Electronics and suitable for high-speed packet buffering, telecom line card memory, and industrial real-time controller cache requiring stable component supply and long-term lifecycle support.

Supply support for 71V3556SA150BQ 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 71V3556SA150BQ belongs to IDT's ZBT SRAM product line, engineered specifically for zero-latency bus turnaround in high-throughput packet-switching and telecom applications demanding deterministic timing and industrial reliability.

FAQ

What is the maximum clock frequency supported by the 71V3556SA150BQ?

The 71V3556SA150BQ is rated for a maximum clock frequency of 150 MHz, corresponding to a 6.67 ns clock cycle time. This rating is validated across the full industrial temperature range (–40°C to +85°C) and under specified 3.3 V ±5% supply conditions. Operation beyond this frequency is not guaranteed and may violate setup/hold timing margins.

Does the 71V3556SA150BQ support both linear and interleaved burst modes?

Yes, the 71V3556SA150BQ supports both linear and interleaved 4-word burst sequences. The LBO (Linear Burst Order) pin selects the mode: LBO = LOW configures linear burst order (A0, A0+1, A0+2, A0+3), while LBO = HIGH selects interleaved order (A0, A0+2, A0+1, A0+3). This selection is static and must remain stable during burst operation.

Is JTAG boundary scan functionality available on all 71V3556SA150BQ packages?

JTAG boundary scan (IEEE 1149.1) is available only on BGA packages including the 71V3556SA150BQ (BQ165). The TMS, TDI, TCK, TDO, and optional TRST pins are assigned to dedicated balls in the fBGA layout. JTAG is not implemented in TQFP or standard BGA variants of the 71V3556SA family.

How does the 71V3556SA150BQ eliminate bus turnaround dead cycles?

The 71V3556SA150BQ eliminates bus turnaround dead cycles via its ZBT™ (Zero Bus Turnaround) architecture: read and write operations are overlapped such that the bus direction change occurs concurrently with internal memory access. This is achieved through pipelined address/control registration and synchronized output buffer enable, removing the need for idle cycles between successive read/write commands.

What is the function of the ZZ pin on the 71V3556SA150BQ?

ZZ is the synchronous sleep mode input on the 71V3556SA150BQ. When asserted HIGH, ZZ gates the internal clock and places the device in its lowest power consumption state while guaranteeing data retention. All I/Os enter high-impedance, and the device remains responsive to CE and CEN transitions for wake-up. ZZ has an internal pulldown resistor.