Renesas 71V3556SA150BG

Overview

71V3556SA150BG 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), pipelined outputs, and 4-word burst capability. It features synchronous address/control/data registers, individual byte write enables (BW1–BW4), and JTAG boundary scan (IEEE 1149.1). Used in high-speed networking line cards and packet buffer applications requiring zero-latency bus turnaround.

For engineers reviewing the 71V3556SA150BG datasheet, 71V3556SA150BG pinout, 71V3556SA150BG application, or 71V3556SA150BG equivalent, key selection criteria include ZBT timing compliance, 100-pin TQFP package compatibility, 3.3V I/O and core supply requirements, industrial temperature support (–40°C to +85°C), and JTAG test interface availability for system-level validation.

Technical Context

The 71V3556SA150BG implements a fully synchronous, clock-edge-triggered architecture where address, control, and data signals are registered on the rising edge of CLK. Its ZBT feature eliminates dead cycles between read and write operations by enabling immediate bus direction reversal without wait states.

It integrates an on-chip 4-word burst counter controlled by ADV/LD and LBO pins, supporting both linear and interleaved burst sequences. Output enable (OE) is asynchronous, while all other inputs-including CE1/CE2/CE2, R/W, CEN, BWx, and ADV/LD-are synchronous with internal pipelining that delivers data two clock cycles after address load.

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, and 66 tolerate VIH-level input without direct VDD connection.

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 71V3556SA150BG uniquely delivers 36-bit ZBT operation with integrated burst counter and IEEE 1149.1 testability-making it optimal for high-throughput, testable, industrial-grade memory subsystems demanding deterministic latency.

Availability

71V3556SA150BG is available at Aetrix Electronics and suitable for high-speed networking equipment, industrial PLCs, and real-time video processing systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 71V3556SA150BG 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, computing, and industrial markets.

The 71V3556SA150BG belongs to IDT's ZBT SRAM product line, engineered specifically for zero-latency bus turnaround in high-speed packet processing, network switching, and real-time control applications demanding deterministic timing and burst efficiency.

FAQ

What is the memory configuration and total capacity of the 71V3556SA150BG?

The 71V3556SA150BG 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 transfers and is optimized for systems requiring wide data paths and high bandwidth, such as network processors and digital signal controllers. The device does not support 256K × 18-bit mode-only the 128K × 36-bit variant is implemented in the 71V3556SA150BG.

Does the 71V3556SA150BG support JTAG boundary scan, and which pins are used?

Yes, the 71V3556SA150BG supports IEEE 1149.1-compliant JTAG boundary scan. The dedicated pins are TMS (Test Mode Select), TDI (Test Data Input), TCK (Test Clock), TDO (Test Data Output), and optional TRST (JTAG Reset). These signals are assigned to specific pins in the 100-pin TQFP package (e.g., TMS on pin A11, TDI on pin A12 per BGA mapping), and TRST is optional with internal pull-up. JTAG functionality is confirmed for the "SA" suffix variant.

How does the ZBTTM feature eliminate dead cycles in the 71V3556SA150BG?

The ZBTTM (Zero Bus Turnaround) feature in the 71V3556SA150BG allows immediate transition between read and write operations without inserting idle cycles. When a read completes and a write is initiated in the next cycle, the bus direction changes synchronously within the same clock domain-enabled by internal pipelining and dual-phase control logic. This eliminates the traditional dead cycle required for bus stabilization, increasing effective bandwidth by up to 25% in mixed-access workloads.

What is the function of the ADV/LD and LBO pins in burst operation of the 71V3556SA150BG?

In the 71V3556SA150BG, ADV/LD controls burst counter behavior: sampled LOW at CLK rise, it loads a new external address; sampled HIGH, it advances the internal 4-word burst counter. LBO selects burst order-LOW enables linear sequence (A0, A1, A2, A3), HIGH enables interleaved (A0, A2, A1, A3). Both pins must be stable before and during burst execution; LBO is static and must not toggle mid-burst.

Can the 71V3556SA150BG operate in sleep mode, and how is it activated?

Yes, the 71V3556SA150BG supports synchronous sleep mode via the ZZ pin. When ZZ is driven HIGH (VIH ≥ 2.0 V), the internal clock is gated, reducing dynamic power consumption significantly while guaranteeing data retention. Sleep mode activation requires CEN = LOW and valid chip enables; the device exits sleep on the next valid CLK edge after ZZ returns LOW. This feature is validated for industrial temperature range operation.