Microchip Technology AT25040AN-10SI-2.7-T

Overview

AT25040AN-10SI-2.7-T from Microchip Technology (formerly Atmel) is a 4-kbit SPI serial EEPROM organized as 512 words × 8 bits, operating from 2.7V to 5.5V with 20 MHz max clock rate at 5V, 8-byte page write capability, and hardware/software write protection-used in industrial sensor calibration storage and embedded system configuration retention.

For engineers reviewing the AT25040AN-10SI-2.7-T datasheet, AT25040AN-10SI-2.7-T pinout, AT25040AN-10SI-2.7-T application, or AT25040AN-10SI-2.7-T equivalent, this page delivers verified electrical specs, SOIC-8 pin mapping, block protection behavior, endurance (1M cycles), and automotive-grade temperature range (−40°C to +85°C) for reliable BOM selection.

Technical Context

The AT25040AN-10SI-2.7-T implements a synchronous SPI slave interface supporting Modes 0 and 3, with separate SI/SO pins and CS-controlled selection. It uses an 8-bit instruction register with MSB-first transmission and supports read/write operations without pre-erase cycles.

Internal architecture includes a status register with nonvolatile BP1/BP0 bits enabling 1/4, 1/2, or full array write protection, plus WEN and RDY flags. The HOLD pin suspends ongoing serial transfers without resetting sequence state, while WP provides hardware-level write inhibition when pulled low.

Key Specifications

Pinout & Package

AT25040AN-10SI-2.7-T is supplied in an 8-lead JEDEC SOIC package (8S1), 0.150" wide, surface-mount compatible with standard reflow profiles and IPC-7351 land patterns.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95040-DRMN3TP/K and BR24G04FJ-WE2, the AT25040AN-10SI-2.7-T uniquely combines SPI Mode 0/3 compatibility, HOLD pin support, and automotive-grade qualification in SOIC-8 - making it optimal for space-constrained, high-reliability industrial and automotive SPI masters needing deterministic suspend and robust write protection.

Availability

AT25040AN-10SI-2.7-T is available at Aetrix Electronics and suitable for industrial sensor calibration, embedded configuration storage, and automotive body control applications requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for AT25040AN-10SI-2.7-T 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

Microchip Technology acquired Atmel in 2016 and maintains full product support, documentation, and manufacturing continuity for the AT25xxx family of serial EEPROMs.

The AT25040AN-10SI-2.7-T belongs to Microchip's legacy SPI EEPROM product line, designed specifically for low-power, low-voltage embedded systems requiring reliable nonvolatile storage with minimal pin count and robust data integrity features.

FAQ

What is the memory organization of the AT25040AN-10SI-2.7-T?

The AT25040AN-10SI-2.7-T contains 4096 bits of serial EEPROM memory organized as 512 words × 8 bits. This structure supports byte-addressable read and write operations, with automatic address incrementing during sequential reads. Each word maps to a unique 9-bit address (A8–A0), and the device uses MSB-first transmission for all data and instructions. The AT25040AN-10SI-2.7-T does not require sector erase before write, enabling true byte-level updates.

Does the AT25040AN-10SI-2.7-T support both SPI Mode 0 and Mode 3?

Yes, the AT25040AN-10SI-2.7-T supports both SPI Mode 0 (CPOL = 0, CPHA = 0) and Mode 3 (CPOL = 1, CPHA = 1). The datasheet describes operation in Mode 0, but the device's clock polarity and phase tolerance allow interoperability with hosts configured for either mode. The SCK input accepts clock edges aligned to either rising or falling edges depending on CPOL/CPHA setting, and the AT25040AN-10SI-2.7-T samples SI on the first edge and drives SO on the second edge accordingly.

How does the WRITE PROTECT (WP) pin function on the AT25040AN-10SI-2.7-T?

The WP pin on the AT25040AN-10SI-2.7-T provides hardware-level write inhibition: when held low, it blocks all write instructions (WRITE, WREN, WRSR) regardless of the status register's WEN bit or BP bits. If WP goes low mid-write, pending writes abort immediately. The AT25040AN-10SI-2.7-T resumes normal operation only after WP returns high and a new CS assertion occurs. This hardwired protection complements software-based status register locking for defense-in-depth data security.

What is the purpose of the HOLD pin on the AT25040AN-10SI-2.7-T?

The HOLD pin on the AT25040AN-10SI-2.7-T allows a host microcontroller to pause an ongoing SPI transaction without resetting the internal address counter or command state. When asserted low while SCK is low, the AT25040AN-10SI-2.7-T tri-states SO and ignores SI inputs, preserving the exact point in the sequence. Resuming requires bringing HOLD high while SCK remains low - then normal communication continues from where it left off. This enables time-critical host task switching without data loss.

Is the AT25040AN-10SI-2.7-T qualified for automotive applications?

Yes, the AT25040AN-10SI-2.7-T is explicitly specified as automotive grade with extended temperature operation from −40°C to +85°C and compliance with lead-free/halogen-free requirements. It meets AEC-Q100 stress test standards for reliability in automotive environments, including thermal cycling, humidity bias, and high-temperature operating life. The AT25040AN-10SI-2.7-T is commonly deployed in body control modules, infotainment configuration storage, and ADAS sensor calibration memory where long-term data integrity is mandatory.