Microchip Technology 25AA010AT-I/OT

Overview

25AA010AT-I/OT 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 mode, 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/OT datasheet, 25AA010AT-I/OT pinout, 25AA010AT-I/OT application, or 25AA010AT-I/OT equivalent, key selection criteria include SPI interface compatibility, low-voltage operation down to 1.8 V, 16-byte page write capability, hardware write-protect pin functionality, and industrial-grade reliability with 1 million erase/write cycles.

Technical Context

The 25AA010AT-I/OT implements a standard SPI Mode 0,0/Multi-Master compatible serial bus interface with separate SI (data in), SO (data out), SCK (clock), CS (chip select), WP (write-protect), and HOLD (suspend) pins. It uses internal high-voltage generation for EEPROM programming and includes a nonvolatile STATUS register with WIP, WEL, BP0, and BP1 bits.

It supports byte and page write operations with automatic address incrementing during sequential reads, self-timed internal write cycles (≤5 ms), and block-level write protection covering none, 1/4, 1/2, or all of the 128-byte memory array. The HOLD function allows pausing ongoing transfers without resetting the sequence.

Key Specifications

Pinout & Package

25AA010AT-I/OT is housed in a 6-pin SOT-23 package (package code OT), optimized for ultra-compact PCB layouts. Pin 1 is marked by laser indentation; orientation follows JEDEC MO-178 standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 25AA010AT-I/OT, the 25AA010A-I/SN offers identical electrical and functional behavior but lacks space efficiency, while the AT25010B-SSHL-T introduces subtle register-level incompatibilities requiring design verification despite matching core capacity and voltage range.

Availability

25AA010AT-I/OT is available at Aetrix Electronics and suitable for smart meter calibration storage, industrial PLC configuration backup, and medical device settings retention requiring stable component supply across extended production lifecycles.

Supply support for 25AA010AT-I/OT 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 leading provider of microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.

The 25AA010A family delivers cost-optimized, low-voltage SPI EEPROMs targeting embedded systems needing reliable, small-footprint nonvolatile storage for configuration, calibration, and event logging.

FAQ

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

The 25AA010AT-I/OT supports up to 10 MHz clock frequency when VCC is 4.5 V to 5.5 V. At lower voltages (2.5–4.5 V), max frequency drops to 5 MHz, and at 1.8–2.5 V, it is limited to 3 MHz per AC Characteristics Table 1-2. These limits ensure setup/hold timing margins are met across voltage and temperature ranges.

Does the 25AA010AT-I/OT require external pull-up resistors on its SO pin?

Yes, the SO pin of the 25AA010AT-I/OT is an open-drain output and requires an external pull-up resistor (typically 4.7 kΩ to VCC) to ensure valid logic-high levels during read operations. This is explicitly specified in the DC Characteristics table (D006 VOH) and confirmed in Figure 1-3 timing diagrams.

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

When the WP pin on the 25AA010AT-I/OT is driven low, it disables all writes to both the memory array and STATUS register-even if the write enable latch (WEL) is set. WP is a hardware override that takes precedence over software write-enable commands, providing robust protection against accidental or malicious overwrites.

What is the page size and how does it affect write operations in the 25AA010AT-I/OT?

The 25AA010AT-I/OT has a fixed 16-byte page size. Page write operations can only span addresses within the same physical page boundary (e.g., 00h–0Fh). Attempting to cross boundaries wraps data to the start of the current page. Firmware must align multi-byte writes to page boundaries to avoid unintended overwrites.

Is the 25AA010AT-I/OT compatible with SPI Mode 1,1 or only Mode 0,0?

The 25AA010AT-I/OT is designed for SPI Mode 0,0 (CPOL = 0, CPHA = 0): SCK idles low, data sampled on rising edge, changed on falling edge. It does not support Mode 1,1. Using incorrect mode causes misaligned sampling and corrupted reads/writes, as confirmed by Figure 1-2 and Section 2.1 of the datasheet.