Microchip Technology AT25040A-10TU-1.8

Overview

AT25040A-10TU-1.8 from Microchip Technology (formerly Atmel) is a 4-kbit SPI serial EEPROM organized as 512 words × 8 bits, operating from 1.8 V to 5.5 V with 20 MHz max clock rate at 5 V, 8-byte page write capability, and hardware/software write protection. It serves as nonvolatile configuration storage in microcontroller-based industrial control modules requiring low-voltage operation and high data retention.

For engineers reviewing the AT25040A-10TU-1.8 datasheet, AT25040A-10TU-1.8 pinout, AT25040A-10TU-1.8 application, or AT25040A-10TU-1.8 equivalent, this page delivers verified electrical specs, TSSOP-8 package mapping, SPI Mode 0/3 compatibility, 1 million write cycles endurance, and real-world use cases in embedded sensor nodes and power management firmware.

Technical Context

The AT25040A-10TU-1.8 implements a synchronous SPI slave interface with separate SI/SO lines, CS-controlled selection, and HOLD pin for pausing serial transfers without resetting the sequence. Its status register supports four block write protection levels (none, 1/4, 1/2, or full array) via BP1/BP0 bits, and it requires WREN before any WRITE instruction.

Internal architecture includes an 8-bit instruction register, address decoder, data register, and self-timed write cycle (≤5 ms). The device powers up in write-disabled state and uses MSB-first transmission; all instructions begin with CS falling edge and include op-code, address, and data fields as defined in the instruction set.

Key Specifications

Pinout & Package

AT25040A-10TU-1.8 is packaged in an 8-lead Thin Shrink Small Outline Package (TSSOP), JEDEC-compliant 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, AT25040A-10TU-1.8 provides optimal balance of SPI flexibility, HOLD interrupt capability, and industrial-grade temperature margin-making it ideal for cost-sensitive, space-constrained embedded systems where SPI is available and +85°C suffices.

Availability

AT25040A-10TU-1.8 is available at Aetrix Electronics and suitable for industrial sensor calibration, smart meter firmware storage, IoT edge node configuration, and motor drive parameter backup requiring stable component supply and long-lifecycle support.

Supply support for AT25040A-10TU-1.8 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 is a global semiconductor company specializing in microcontrollers, analog, FPGA, and memory solutions, with a focus on embedded control and connectivity.

The AT25040A-10TU-1.8 belongs to Microchip's legacy serial EEPROM product line, engineered for reliable, low-power nonvolatile data storage in resource-constrained embedded systems across industrial, consumer, and communications markets.

FAQ

What is the maximum clock frequency supported by AT25040A-10TU-1.8 at 1.8 V operation?

At 1.8 V supply, the AT25040A-10TU-1.8 supports up to 5 MHz SCK frequency per Table 4 AC Characteristics. This is lower than its 20 MHz rating at 5 V, reflecting reduced internal timing margins at minimum voltage. Designers must configure their SPI peripheral accordingly to avoid setup/hold violations.

Does AT25040A-10TU-1.8 support SPI Mode 1 or Mode 2?

No, AT25040A-10TU-1.8 explicitly supports only SPI Modes 0 (CPOL=0, CPHA=0) and 3 (CPOL=1, CPHA=1), as stated in the Features section. Modes 1 and 2 are not compatible due to fixed sampling and output timing relative to SCK edges. Using unsupported modes will result in corrupted reads/writes.

How does the HOLD pin function during an active write cycle in AT25040A-10TU-1.8?

The HOLD pin has no effect during an internal write cycle (tWC); once initiated, the write proceeds to completion regardless of HOLD state. HOLD only suspends serial communication during read/write instruction sequences *before* CS rising edge triggers the internal cycle. During tWC, only RDSR is accepted.

Can AT25040A-10TU-1.8 be used in automotive applications?

Per the official datasheet disclaimer, AT25040A-10TU-1.8 is not intended, authorized, or warranted for automotive applications. It is qualified for industrial temperature (−40°C to +85°C), but lacks AEC-Q100 qualification, extended temperature screening, or automotive-specific reliability testing required for under-hood or safety-critical use.

What happens if the WP pin is pulled low during a WREN instruction on AT25040A-10TU-1.8?

If WP is low during WREN execution, the AT25040A-10TU-1.8 ignores the instruction and remains in write-disabled state. The datasheet specifies that WP must be held high during WREN to successfully set the WEN bit; violating this condition prevents subsequent WRITE or WRSR commands from executing.