Renesas AT25DF256-XMHNGU-B

Overview

AT25DF256-XMHNGU-B from Renesas Electronics is a 256-Kbit serial SPI Flash memory IC designed for code shadowing and data storage in embedded systems. It operates from 1.65 V to 3.6 V, supports SPI Modes 0/3 and Dual-Output Read, delivers 104 MHz max clock frequency, achieves 6 ns clock-to-output delay, and features uniform 4-kByte and 32-kByte block erase with 256-byte page erase - used in IoT edge nodes, industrial HMIs, and portable medical devices.

For engineers reviewing the AT25DF256-XMHNGU-B datasheet, AT25DF256-XMHNGU-B pinout, AT25DF256-XMHNGU-B application, or AT25DF256-XMHNGU-B equivalent, key selection criteria include dual-read throughput, ultra-deep power-down current (200 nA), OTP security register programmability, hardware write protection via WP pin, and compatibility with 8-lead SOIC, TSSOP, and 2×3 mm UDFN packages.

Technical Context

The AT25DF256-XMHNGU-B implements a dedicated SPI interface with dual-bit output capability using SI and SO pins simultaneously during Dual-Output Read (3Bh opcode), enabling 2× data throughput versus standard read. Its memory architecture supports hierarchical erasure - 256-byte pages, 4-kByte blocks, 32-kByte blocks, and full-chip - optimized for mixed code/data firmware layouts.

Internal logic includes status register byte 1 and byte 2 for configuration of block protection, deep power-down mode, and write enable state; OTP security register contains 64 bytes factory-programmed unique ID and 64 bytes user-programmable space; hardware locking is controlled by WP pin assertion and status register bits BPL and SEC.

Key Specifications

Pinout & Package

AT25DF256-XMHNGU-B is packaged in an 8-lead SOIC (150-mil) per JEDEC MS-012, with lead finish Pb/Halide-free and RoHS compliance. Pin functions are electrically identical across SOIC, TSSOP, and UDFN variants.

Key Features

Applications

Equivalent & Alternatives

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

Compared with W25Q256JWEIQ and MX25L25635FMI-12G, AT25DF256-XMHNGU-B uniquely combines 1.65 V operation, dual-output read, OTP security, and 200 nA ultra-deep power-down - making it optimal for compact, battery-powered, security-aware embedded systems where voltage flexibility and low-latency reads are essential.

Availability

AT25DF256-XMHNGU-B is available at Aetrix Electronics and suitable for IoT edge node firmware storage, industrial HMI configuration memory, and portable medical device log memory requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for AT25DF256-XMHNGU-B 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, infrastructure, and IoT markets.

The AT25DF256 product line targets cost-sensitive, space-constrained embedded systems needing reliable, low-voltage serial Flash with flexible erase and enhanced security - especially where mixed code/data storage and ultra-low power consumption are critical.

FAQ

What is the maximum operating frequency supported by the AT25DF256-XMHNGU-B?

The AT25DF256-XMHNGU-B supports a maximum clock frequency of 104 MHz for most commands including Read Array (0Bh), Page Erase (81h), and Block Erase (20h/52h). This enables high-throughput data access and rapid firmware updates. The device maintains timing integrity across its full 1.65–3.6 V supply range and -40 °C to +85 °C temperature range, as verified in AC characteristics Table 13.4 of the official datasheet DS-AT25DF256-035 Rev.G.

Does the AT25DF256-XMHNGU-B support Dual-Output Read, and what is its benefit?

Yes, the AT25DF256-XMHNGU-B supports Dual-Output Read using opcode 3Bh, where both SI and SO pins act as outputs to deliver two bits per clock cycle. This doubles effective read bandwidth compared to standard single-output read (0Bh/03h), reducing firmware load time and improving real-time data streaming performance. The feature is fully compatible with SPI Modes 0 and 3 and requires no additional hardware beyond standard SPI wiring.

What is the purpose and structure of the OTP Security Register in the AT25DF256-XMHNGU-B?

The AT25DF256-XMHNGU-B includes a 128-byte One-Time Programmable (OTP) Security Register: 64 bytes are factory-programmed with a unique identifier for device serialization, and 64 bytes are user-programmable for storing secure keys, calibration data, or electronic serial numbers. Once programmed, OTP bytes cannot be erased or rewritten - ensuring permanent, tamper-resistant storage critical for authentication and traceability in regulated applications.

How does hardware write protection work on the AT25DF256-XMHNGU-B?

Hardware write protection on the AT25DF256-XMHNGU-B is controlled by the WP pin and status register bits BPL (Block Protect Lockdown) and SEC (Security Register Protection). When WP is driven low and BPL=1, sectors defined by status register bits BP2–BP0 become permanently locked against program/erase. The WP pin is internally pulled high, so it must be externally tied to GND to activate protection - preventing accidental writes during power transients or software faults.

What power-saving modes does the AT25DF256-XMHNGU-B offer, and how low is the current draw?

The AT25DF256-XMHNGU-B offers Deep Power-Down (5 µA typical) and Ultra-Deep Power-Down (200 nA typical) modes, entered via B9h and 79h opcodes respectively. These modes disable internal circuitry while retaining memory contents, enabling multi-year battery life in always-on endpoints. Exit is achieved with ABh (resume) or chip-select toggle (ultra-deep), with no reset required - preserving system state and minimizing wake-up latency for the AT25DF256-XMHNGU-B.