Renesas AT25SF081B-DWF

Overview

AT25SF081B from Renesas Electronics is an 8 M-bit SPI serial flash memory IC designed for embedded boot code storage and execute-in-place (XiP) applications. It supports dual I/O (1-2-2) and quad I/O (1-4-4, 0-4-4) read modes, operates up to 108 MHz, and delivers fast read performance with continuous wrap modes. Its flexible erase architecture (4 kB/32 kB/64 kB sectors) and OTP security registers make it suitable for industrial microcontroller boot loaders requiring secure, low-power firmware storage.

For engineers reviewing the AT25SF081B datasheet, AT25SF081B pinout, AT25SF081B application, or AT25SF081B equivalent, key selection criteria include XiP support via 0-4-4 command mode, deep power-down current (1.2 µA), JEDEC-standard SFDP register compliance, and dual/quad I/O timing compatibility with ARM Cortex-M and RISC-V host controllers.

Technical Context

The AT25SF081B implements a unified SPI interface supporting all standard modes (0 and 3), with configurable I/O width via Status Register 2's Quad Enable (QE) bit. Its internal architecture includes a 2 Mbit physical block structure, SRAM data buffer, and Y/X-decoder array enabling efficient page programming (1–256 bytes) and sector/block erases.

Command execution is managed by control logic that handles suspend/resume during program/erase cycles, while protection is enforced through volatile/non-volatile status bits, WP pin assertion, and 3×256-byte OTP security registers accessible via dedicated 42h/44h/48h/4Bh opcodes.

Key Specifications

Pinout & Package

AT25SF081B is available in three RoHS-compliant packages: 8-lead SOIC (150-mil narrow and 208-mil wide) and 8-pad Ultra-Thin UDFN (2 × 3 × 0.6 mm). All variants share identical 8-pin functionality and pinout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial flash memory applications.

Compared with Winbond W25Q80DV and Micron MT25QL08GA, the AT25SF081B uniquely integrates OTP security registers and full dual/quad I/O flexibility-including 0-4-4 continuous-read mode-making it optimal for secure, low-latency embedded boot applications where firmware integrity and startup speed are co-prioritized.

Availability

AT25SF081B is available at Aetrix Electronics and suitable for industrial PLC firmware storage, automotive ADAS boot memory, and medical infusion pump code storage requiring stable component supply across multi-year production programs.

Supply support for AT25SF081B 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog, power, and memory solutions for automotive, industrial, and IoT markets.

The AT25SF081B belongs to Renesas' AT25SF family of SPI flash memories engineered specifically for execute-in-place (XiP) boot applications in resource-constrained embedded systems requiring low power, high reliability, and hardware-level security.

FAQ

What is the maximum operating frequency supported by the AT25SF081B?

The AT25SF081B supports a maximum SPI clock frequency of 108 MHz in quad I/O (1-4-4 and 0-4-4) modes. This enables high-throughput instruction fetch for execute-in-place (XiP) applications. In standard single-I/O mode, the maximum frequency remains 108 MHz, though effective bandwidth is reduced. The device maintains timing compliance across its full 2.5 V–3.6 V supply range and -40°C to +85°C temperature range, as verified in AC Characteristics Table 13.4 of the official datasheet DS-AT25SF081B-189 Rev. H.

Does the AT25SF081B support execute-in-place (XiP) operation?

Yes, the AT25SF081B explicitly supports execute-in-place (XiP) operation via its 0-4-4 command mode (opcode EBh), which eliminates the need to send repeated read opcodes during continuous instruction fetch. This feature, combined with 108 MHz quad I/O speed and continuous read wrap (8/16/32/64-byte), reduces CPU wait states and accelerates boot time. The Product Overview section on page 6 of DS-AT25SF081B-189 confirms XiP is a core design objective enabled by these hardware features.

How many one-time programmable (OTP) security registers does the AT25SF081B include?

The AT25SF081B includes three 256-byte one-time programmable (OTP) security registers, accessible via dedicated commands: 42h (program), 44h (erase), 48h (read), and 4Bh (read unique ID). These registers are physically isolated and permanently locked after programming, making them suitable for storing cryptographic keys, device identifiers, or calibration data. Their existence and command set are fully documented in Section 10 of DS-AT25SF081B-189 Rev. H.

What package options are available for the AT25SF081B?

The AT25SF081B is offered in three industry-standard RoHS-compliant packages: 8-lead SOIC (150-mil narrow body), 8-lead SOIC (208-mil wide body), and 8-pad Ultra-Thin UDFN (2 mm × 3 mm × 0.6 mm). All packages share identical pinout and electrical characteristics. Packaging details, including mechanical drawings and land patterns, are specified in Section 16 of DS-AT25SF081B-189 Rev. H, with Figure 1 and Figure 2 illustrating top-view layouts for SOIC and UDFN variants respectively.

Does the AT25SF081B support Serial Flash Discoverable Parameters (SFDP)?

Yes, the AT25SF081B implements JEDEC Standard JESD216-compliant Serial Flash Discoverable Parameters (SFDP) via the 5Ah command. This register provides standardized, runtime-accessible metadata including timing parameters, erase block sizes, and feature flags-enabling portable flash drivers across different host platforms. SFDP support is explicitly listed in the Features section on page 1 and detailed in Section 7.7 of DS-AT25SF081B-189 Rev. H.