Microchip Technology AT25040A-10TU-2.7-T

Overview

AT25040A-10TU-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 via WP pin and status register. It serves as nonvolatile configuration storage in industrial control modules requiring low-voltage operation and high endurance.

For engineers reviewing the AT25040A-10TU-2.7-T datasheet, AT25040A-10TU-2.7-T pinout, AT25040A-10TU-2.7-T application, or AT25040A-10TU-2.7-T equivalent, key selection criteria include VCC range compatibility (2.7–5.5V), TSSOP-8 package footprint, SPI Mode 0/3 support, 1 million write cycles, and block-level write protection granularity (1/4, 1/2, or full array).

Technical Context

The AT25040A-10TU-2.7-T implements a synchronous SPI slave interface with separate SI/SO lines, CS-controlled selection, and HOLD pin for serial communication suspension without reset. Its internal architecture includes an 8-bit instruction register, status register with BP1/BP0 protection bits, and automatic address increment during page writes.

It supports self-timed internal write cycles (≤5 ms), requires WREN before WRITE, and enforces write inhibition when WP = low or WEN = 0. The device powers up in write-disabled state and provides RDSR-based ready/busy polling - no external erase cycle is needed.

Key Specifications

Pinout & Package

AT25040A-10TU-2.7-T uses an 8-lead Thin Shrink Small Outline Package (TSSOP), JEDEC standard 8A2 footprint (3.00 mm × 4.40 mm body, 0.65 mm pitch), RoHS-compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95040-DRMN6TP/K and BR24G04FJ-WE2, the AT25040A-10TU-2.7-T offers guaranteed SPI Mode 0/3 interoperability with legacy microcontrollers, integrated HOLD functionality for deterministic bus arbitration, and optimized 8-byte page writes - making it preferable for real-time embedded systems where SPI bandwidth and interrupt latency matter.

Availability

AT25040A-10TU-2.7-T is available at Aetrix Electronics and suitable for industrial automation, smart metering, and automotive body electronics requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for AT25040A-10TU-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 technical and manufacturing continuity for the AT25xxx family of serial EEPROMs.

The AT25040A-10TU-2.7-T belongs to Microchip's industrial-grade serial EEPROM product line, designed specifically for robust nonvolatile data storage in harsh environments where reliability, low power, and SPI simplicity are prioritized over high density or speed.

FAQ

What is the maximum clock frequency supported by the AT25040A-10TU-2.7-T?

The AT25040A-10TU-2.7-T supports up to 20 MHz SCK frequency at VCC = 5.0V, 10 MHz at VCC = 2.7–3.6V, and 5 MHz at VCC = 1.8–2.6V. These limits are defined in Table 4 of the datasheet and reflect timing margins for reliable setup/hold compliance across voltage and temperature ranges. The AT25040A-10TU-2.7-T must not be operated above its rated fSCK for its applied VCC.

Does the AT25040A-10TU-2.7-T require an external erase command before writing?

No, the AT25040A-10TU-2.7-T does not require a separate erase command. Each WRITE instruction automatically erases and programs the target byte(s) in a self-timed internal cycle. The device uses floating-gate technology that integrates erase and program phases - only WREN and WRITE instructions are needed to modify data, provided write protection is disabled.

How does the WP pin interact with the status register write protection bits in the AT25040A-10TU-2.7-T?

In the AT25040A-10TU-2.7-T, the WP pin provides hardware-level write inhibition independent of the status register. When WP = low, all write operations (including WRSR) are blocked regardless of BP1/BP0 settings. When WP = high, protection is controlled solely by the status register bits. This dual-layer scheme ensures fail-safe protection against both software errors and physical signal faults.

What is the function of the HOLD pin on the AT25040A-10TU-2.7-T?

The HOLD pin on the AT25040A-10TU-2.7-T suspends ongoing SPI communication (read or write) without resetting the internal address counter or command state. When asserted low while SCK is low, it places SO in high-impedance and ignores SI inputs until de-asserted. This allows the host MCU to service higher-priority interrupts and resume exactly where the AT25040A-10TU-2.7-T transaction left off.

Is the AT25040A-10TU-2.7-T pin-compatible with other members of the AT250xxA family?

Yes, the AT25040A-10TU-2.7-T shares identical pinout, package (TSSOP-8), and electrical interface with AT25010A-10TU-2.7-T and AT25020A-10TU-2.7-T. All three devices use the same CS/SCK/SI/SO/WP/HOLD/GND/VCC arrangement and support identical instruction set and timing - enabling memory capacity upgrades without PCB redesign.