Microchip Technology 25AA010AT-I/ST

Overview

25AA010AT-I/ST from Microchip Technology Inc. is a 1 Kbit SPI Serial EEPROM with 128 × 8-bit organization, 1.8–5.5 V supply range, and industrial temperature rating (–40°C to +85°C). It supports up to 10 MHz clock frequency, 16-byte page write, and hardware write protection via WP pin - used for configuration storage in microcontroller-based embedded systems requiring nonvolatile parameter retention.

For engineers reviewing the 25AA010AT-I/ST datasheet, 25AA010AT-I/ST pinout, 25AA010AT-I/ST application, or 25AA010AT-I/ST equivalent, key selection criteria include SPI interface compatibility, low-voltage operation down to 1.8 V, page-write timing (≤5 ms), block protection granularity (none/¼/½/all), and ST-packaged 8-lead TSSOP mechanical fit in space-constrained PCB layouts.

Technical Context

The 25AA010AT-I/ST implements a standard SPI Mode 0,0 (CPOL=0, CPHA=0) interface with separate SI/SO lines and active-low CS. It uses an internal high-voltage generator for EEPROM programming and includes a status register with WIP, WEL, BP0, and BP1 bits for real-time write monitoring and configurable block protection.

Its HOLD pin enables mid-sequence pause without resetting the serial transaction, while WP provides hardware-level write inhibition independent of software state. The device powers on with WEL reset and SO in high-impedance, ensuring safe bus sharing in multi-peripheral SPI configurations.

Key Specifications

Pinout & Package

25AA010AT-I/ST is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, compliant with JEDEC MO-153, and marked "25AA010A" with temperature grade "I" and date code.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA010AT-I/ST, the 25AA010A-I/P offers identical functionality in through-hole format for legacy or test environments, while the AT25010B-SSHL-T provides second-source availability with minor timing variations that require validation in high-speed or timing-critical SPI implementations.

Availability

25AA010AT-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration storage, and consumer appliance settings requiring stable component supply with guaranteed long-term manufacturability.

Supply support for 25AA010AT-I/ST 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 Inc. is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory products for embedded control applications.

The 25AA010A family was designed to deliver cost-effective, low-power serial EEPROM solutions for configuration and parameter storage in microcontroller-based systems across industrial, medical, and consumer markets.

FAQ

What is the maximum clock frequency supported by the 25AA010AT-I/ST?

The 25AA010AT-I/ST supports a maximum clock frequency of 10 MHz when VCC is 4.5 V to 5.5 V. At lower voltages (2.5–4.5 V), the limit drops to 5 MHz, and at 1.8–2.5 V, it is 3 MHz. These graded limits ensure reliable SPI communication across its full 1.8–5.5 V operating range without violating setup/hold timing margins.

How does the WRITE PROTECT (WP) pin function on the 25AA010AT-I/ST?

When the WP pin on the 25AA010AT-I/ST is driven low, all write operations to both memory array and STATUS register are disabled - even if the write enable latch (WEL) is set. This hardware-level protection remains active regardless of software state and cannot be overridden by commands. WP high restores full write capability.

Can the 25AA010AT-I/ST perform page writes across address boundaries?

No. The 25AA010AT-I/ST restricts page writes to addresses within a single 16-byte physical page (e.g., 0x00–0x0F, 0x10–0x1F). Attempting to write across a boundary causes wraparound to the start of the current page, overwriting prior data. Application firmware must enforce page alignment to prevent unintended data loss during multi-byte writes.

What is the purpose of the HOLD pin on the 25AA010AT-I/ST?

The HOLD pin on the 25AA010AT-I/ST allows pausing an ongoing SPI transaction (e.g., mid-read or mid-write) without aborting or restarting the sequence. When pulled low while SCK is low, SI/SO/SCK are tri-stated and ignored; resuming requires bringing HOLD high while SCK remains low. This enables MCU interrupt servicing without SPI re-synchronization overhead.

Does the 25AA010AT-I/ST require external components for basic operation?

No. The 25AA010AT-I/ST operates with only VCC, VSS, and SPI signals (CS, SCK, SI, SO); WP and HOLD are optional. No external pull-ups, capacitors, or voltage regulators are needed for standard read/write operation. A 0.1 µF decoupling capacitor near VCC is recommended for noise suppression but is not strictly required for functional correctness.