Microchip Technology 24AA025E64T-I/SN

Overview

24AA025E64T-I/SN from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM with factory-programmed, globally unique EUI-64™ node address stored in write-protected memory (0xF8–0xFF). It operates from 1.7V to 5.5V, supports 400 kHz I²C clock (100 kHz at VCC <2.5V), and delivers ≤1 µA standby current (I-temp) for low-power embedded identity storage in networked devices.

For engineers reviewing the 24AA025E64T-I/SN datasheet, 24AA025E64T-I/SN pinout, 24AA025E64T-I/SN application, or 24AA025E64T-I/SN equivalent, key selection criteria include EUI-64™ pre-programming integrity, 16-byte page write capability, cascading support via A0/A1/A2 address pins, and SOIC-8 package compatibility with industrial temperature range (−40°C to +85°C).

Technical Context

The 24AA025E64T-I/SN implements a two-block 128 × 8-bit EEPROM array with hardware-enforced write protection on upper half (0x80–0xFF), where the EUI-64™ address resides. Its I²C slave interface uses Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce on shared buses.

It supports cascaded addressing: A0, A1, and A2 pins enable up to eight devices on one bus (four in 6-lead SOT-23), with chip-select bits mapped to address bits A8–A10 for contiguous 16K-bit expansion. Internal acknowledge polling allows host firmware to detect end-of-write without fixed delays.

Key Specifications

Pinout & Package

24AA025E64T-I/SN is supplied in an 8-lead SOIC (SN) package, 3.90 mm body width, with standard pinout and no NC pins. Pin 1 = A0, Pin 2 = A1, Pin 3 = A2, Pin 4 = VSS, Pin 5 = SDA, Pin 6 = SCL, Pin 7 = NC, Pin 8 = VCC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar EEPROM-with-preprogrammed-identity applications.

Compared with 24AA02E64T-I/SN and AT24MAC402-MAHM-T, the 24AA025E64T-I/SN uniquely balances EUI-64™ compliance, cascading flexibility via A0–A2, and SOIC-8 footprint compatibility - making it optimal for industrial control boards where layout reuse and multi-node scalability are critical.

Availability

24AA025E64T-I/SN is available at Aetrix Electronics and suitable for industrial IoT sensor nodes, networked medical devices, smart building controllers, and automotive telematics modules requiring stable component supply with guaranteed long-term availability.

Supply support for 24AA025E64T-I/SN 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 components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA02XEXX product line was designed specifically for secure, factory-provisioned node identity in resource-constrained embedded systems - integrating IEEE-compliant EUI addressing with robust serial EEPROM functionality.

FAQ

What is the exact memory organization and protected area of the 24AA025E64T-I/SN?

The 24AA025E64T-I/SN contains 2 Kbit (256 bytes) of EEPROM organized as two 128-word blocks. The upper half (addresses 0x80–0xFF, 128 bytes) is permanently write-protected and stores the factory-programmed EUI-64™ node address (0xF8–0xFF). The lower half (0x00–0x7F) is fully readable and writable for user data. This partitioning ensures identity integrity while allowing flexible application use of remaining memory.

Does the 24AA025E64T-I/SN support true I²C multi-master arbitration?

No - the 24AA025E64T-I/SN is a slave-only I²C device and does not implement multi-master arbitration logic. It responds only to its configured slave address (1010 A2 A1 A0) and relies entirely on the master to control bus timing, START/STOP conditions, and collision avoidance. Arbitration responsibility lies with the system master controller, not the 24AA025E64T-I/SN.

Can the EUI-64™ address in the 24AA025E64T-I/SN be reprogrammed or modified after factory programming?

No - the EUI-64™ address in the 24AA025E64T-I/SN is written during final test and permanently locked in the write-protected memory region (0xF8–0xFF). No command, voltage condition, or sequence can alter this value. Attempts to write to addresses 0x80–0xFF will be ignored, preserving IEEE compliance and cryptographic binding integrity throughout the device lifetime.

What is the maximum number of 24AA025E64T-I/SN devices that can be cascaded on a single I²C bus?

Up to eight 24AA025E64T-I/SN devices can be cascaded on a single I²C bus using the A0, A1, and A2 address pins to configure unique 3-bit chip select values (1010 A2 A1 A0). In the 6-lead SOT-23 variant, A2 is not bonded out, limiting cascading to four devices. The SOIC-8 version used in 24AA025E64T-I/SN fully supports all eight combinations.

How does the 24AA025E64T-I/SN handle power loss during a write cycle?

The 24AA025E64T-I/SN incorporates an internal VCC threshold detector that disables erase/write logic if VCC drops below ~1.5V. Combined with self-timed write cycles and EEPROM cell architecture, this ensures atomicity: partial writes do not corrupt existing data. If power fails mid-cycle, the device resumes normal operation upon recovery, and the incomplete write is discarded - no data corruption or state lockup occurs in the 24AA025E64T-I/SN.