Microchip Technology 24AA025E48T-E/OT

Overview

24AA025E48T-E/OT from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM with factory-programmed EUI-48™ node identity, 16-byte page write buffer, and operation down to 1.7 V. It delivers 1 µA max standby current (I-temp), supports 400 kHz clock (≥2.5 V), and is housed in a RoHS-compliant 6-lead SOT-23 package for space-constrained embedded networking nodes.

For engineers reviewing the 24AA025E48T-E/OT datasheet, 24AA025E48T-E/OT pinout, 24AA025E48T-E/OT application, or 24AA025E48T-E/OT equivalent, this page provides verified electrical specs, validated pin functions, confirmed EUI-48™ memory mapping, and real-world use cases in industrial Ethernet nodes, automotive telematics modules, and IoT edge sensors requiring globally unique MAC address storage.

Technical Context

The 24AA025E48T-E/OT implements a two-block 128 × 8-bit EEPROM array with hardware write protection on upper half (0x80–0xFF). Its I²C slave interface uses Schmitt-triggered SDA/SCL inputs with 0.05 VCC hysteresis and slope-controlled outputs to suppress ground bounce.

It supports cascaded addressing via A0/A1/A2 chip-select pins (A2 unconnected in SOT-23), enabling up to four devices on one bus. Internal voltage threshold detection disables erase/write below 1.5 V, and acknowledge polling allows precise timing of self-timed 5 ms write cycles.

Key Specifications

Pinout & Package

6-lead SOT-23 package (JEDEC MO-178AA), 1.6 mm × 2.8 mm footprint, 0.95 mm height, gull-wing leads. Pin 1 marked by beveled corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM with factory-programmed node identity applications.

Compared with 24AA025E48T-E/OT, the 24AA02E48T-I/OT reduces system cost and complexity in single-device applications but forfeits bus scalability, while the AT24CM02-SSHM-T offers identical core functionality in a different package but eliminates cascading entirely - making 24AA025E48T-E/OT the sole choice for compact, multi-node identity architectures.

Availability

24AA025E48T-E/OT is available at Aetrix Electronics and suitable for industrial Ethernet nodes, automotive telematics modules, and IoT edge sensors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 24AA025E48T-E/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, FPGA, and memory solutions, serving industrial, automotive, communications, and consumer markets with high-reliability silicon and development tools.

The 24AA025E48T-E/OT belongs to Microchip's 24AA02XE family of pre-programmed identity EEPROMs, designed specifically to simplify IEEE-compliant MAC address management in resource-constrained embedded systems.

FAQ

What is the exact memory organization and EUI-48™ location for 24AA025E48T-E/OT?

The 24AA025E48T-E/OT contains 256 bytes (2 Kbit) organized as two 128-byte blocks. Its factory-programmed EUI-48™ address occupies memory addresses 0xFA through 0xFF - six contiguous bytes where the first three are Microchip's IEEE-assigned OUI and the last three form the unique extension identifier. This region is permanently write-protected; only the lower 128 bytes (0x00–0x7F) are user-writable. The 24AA025E48T-E/OT retains this exact mapping per DS20002124H.

Does 24AA025E48T-E/OT support cascaded I²C addressing, and how many devices can share one bus?

Yes, 24AA025E48T-E/OT supports cascaded addressing using its A0 and A1 pins (A2 is not connected in the 6-lead SOT-23 package). These two inputs define the two least-significant bits of the 3-bit chip address, allowing up to four 24AA025E48T-E/OT devices on a single I²C bus. Each device must have a unique A0/A1 combination (e.g., 00, 01, 10, 11); tying both to VSS selects address 0x50. This capability is explicitly confirmed for the 24AA025E48 variant in the Device Selection Table.

What is the maximum write cycle time for 24AA025E48T-E/OT, and how can it be managed in real-time systems?

The maximum write cycle time for 24AA025E48T-E/OT is 5 ms, covering both byte and page writes. Real-time systems manage this using acknowledge polling: after issuing a STOP condition to initiate writing, the master repeatedly sends a START + control byte (R/W = 0) until the device responds with an ACK - confirming write completion. This method avoids fixed delays and ensures deterministic timing. The 24AA025E48T-E/OT datasheet (DS20002124H, Figure 7-1) validates this behavior.

Is 24AA025E48T-E/OT qualified for automotive applications, and what temperature range does it support?

Yes, the "E" suffix in 24AA025E48T-E/OT denotes Automotive qualification per Microchip's extended temperature grade, rated from –40°C to +125°C. It meets AEC-Q100 stress test requirements for reliability in automotive environments. Standby current remains ≤5 µA across this full range, and all AC/DC specifications - including 400 kHz I²C operation and Schmitt-trigger noise immunity - are guaranteed over –40°C to +125°C. This is documented in the Device Selection Table and Electrical Characteristics sections of DS20002124H.

How does the 16-byte page write buffer in 24AA025E48T-E/OT improve system efficiency compared to 8-byte alternatives?

The 16-byte page write buffer in 24AA025E48T-E/OT doubles the data payload per I²C transaction versus 8-byte variants like the 24AA02E48, reducing bus overhead by up to 50% for bulk configuration writes. For example, storing a 32-byte calibration table requires only two page writes instead of four - cutting total SCL clocks, CPU wake-ups, and power consumption. This advantage is specific to the "25" variant and confirmed in the Device Selection Table and Section 6.2 of DS20002124H.