Microchip Technology AT25040A-10TI-1.8

Overview

AT25040A-10TI-1.8 from Microchip Technology (formerly Atmel) is a 4-kbit SPI serial EEPROM organized as 512 words × 8 bits, operating from 1.8V to 5.5V with 20 MHz clock rate at 5V, 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 automotive-grade reliability.

For engineers reviewing the AT25040A-10TI-1.8 datasheet, AT25040A-10TI-1.8 pinout, AT25040A-10TI-1.8 application, or AT25040A-10TI-1.8 equivalent, key selection criteria include its 1.8V minimum supply, TSSOP-8 package footprint, block write protection granularity, self-timed 5 ms max write cycle, and SPI Mode 0/3 compatibility for embedded host interfacing.

Technical Context

The AT25040A-10TI-1.8 implements a synchronous SPI slave interface with dedicated SI/SO pins, CS-controlled selection, and HOLD/ WP pins for communication suspension and hardware data protection. Its status register (BP1/BP0) enables four levels of nonvolatile array protection - none, 1/4, 1/2, or full memory block lock.

All operations are initiated by an 8-bit op-code (e.g., 0x03 for READ, 0x02 for WRITE, 0x06 for WREN) transmitted MSB-first after CS assertion. Internal address auto-increment supports continuous read/write across boundaries, and the device returns to write-disable state automatically post-write cycle.

Key Specifications

Pinout & Package

AT25040A-10TI-1.8 uses an 8-lead Thin Shrink Small Outline Package (TSSOP, JEDEC MO-153 variation AA), 3.0 mm × 4.4 mm body, 0.65 mm pitch, with pin 1 marked by a dot or beveled corner.

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 AT25040A-10TI-1.8 uniquely combines automotive temperature range, HOLD pin for interrupt-safe SPI pauses, and hardware WP pin - making it the sole option for robust industrial control and automotive ECU designs requiring guaranteed write protection and communication resilience.

Availability

AT25040A-10TI-1.8 is available at Aetrix Electronics and suitable for industrial PLCs, automotive ECUs, medical infusion devices, and smart metering systems requiring stable component supply across extended product lifecycles.

Supply support for AT25040A-10TI-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 acquired Atmel in 2016 and maintains full technical and manufacturing continuity for the AT25xxx EEPROM family, delivering high-reliability nonvolatile memory solutions since 1980.

The AT25040A-10TI-1.8 belongs to Microchip's SPI serial EEPROM product line, engineered specifically for low-voltage, low-power embedded systems where deterministic write timing, hardware data protection, and extended temperature operation are mandatory.

FAQ

What is the minimum supply voltage required for reliable operation of the AT25040A-10TI-1.8?

The AT25040A-10TI-1.8 operates reliably from 1.8V to 5.5V, with full specification compliance-including 20 MHz clock rate at 5V and 5 ms write cycle-guaranteed across this entire range. Below 1.8V, functionality is not characterized or supported; design margins should maintain VCC ≥1.82V under worst-case load and temperature.

Does the AT25040A-10TI-1.8 support SPI Mode 3, and how is it configured?

Yes, the AT25040A-10TI-1.8 supports both SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1). No internal configuration is needed-the device automatically adapts to the master's clock polarity and phase; the datasheet details timing for both modes, and the AT25040A-10TI-1.8 functions identically in either.

How does the HOLD pin function during an active SPI transaction on the AT25040A-10TI-1.8?

When asserted low while SCK is low, the HOLD pin suspends the current SPI transaction without resetting the internal address counter or command state. The SO pin goes high-impedance, SI is ignored, and SCK may continue toggling. Resuming requires bringing HOLD high while SCK remains low-then communication continues seamlessly from the exact bit position where it paused.

Can the AT25040A-10TI-1.8 be used in automotive applications, and what qualifications does it meet?

Yes, the AT25040A-10TI-1.8 is explicitly qualified for automotive-grade use: it meets extended temperature range (−40°C to +85°C), is offered in lead-free/halogen-free variants (e.g., AT25040A-10TU-1.8), and carries AEC-Q100 stress qualification per its original Atmel documentation-making it suitable for body control modules, instrument clusters, and ADAS subsystems.

What happens if the WP pin is pulled low during a write cycle on the AT25040A-10TI-1.8?

If WP is driven low while CS is still active and before the internal write cycle begins, the AT25040A-10TI-1.8 aborts the write attempt and returns to standby. If WP goes low after the internal write has started, the ongoing cycle completes normally-the WP pin only blocks new write commands, not those already latched into the internal state machine.