Microchip Technology 24AA02UID-I/P

Overview

24AA02UID-I/P from Microchip Technology Inc. is a 2 Kbit I²C-compatible serial EEPROM with a factory-programmed, globally unique 32-bit serial number stored in write-protected memory (addresses 0xFC–0xFF). It operates from 1.7V to 5.5V, supports up to 400 kHz clock frequency (100 kHz below 2.5V), and delivers 1 µA max standby current and 1 mA max read current. It is used for secure device identification in embedded systems requiring tamper-resistant, nonvolatile identity storage.

For engineers reviewing the 24AA02UID-I/P datasheet, 24AA02UID-I/P pinout, 24AA02UID-I/P application, or 24AA02UID-I/P equivalent, this page provides verified electrical parameters, SOT-23/PDIP/SOIC package mapping, I²C timing compliance, preprogrammed UID access methodology, and validated alternative parts for identity EEPROM replacement scenarios.

Technical Context

The 24AA02UID-I/P implements a two-wire I²C slave interface with Schmitt-trigger inputs and slope-controlled outputs to suppress noise and eliminate ground bounce. Its internal address counter enables current-address, random, and sequential reads across its 256-byte memory array (128 × 8-bit per block), with the upper half (0x80–0xFF) permanently write-protected to preserve the UID and manufacturer codes.

It uses self-timed erase/write cycles with an 8-byte page buffer, 3 ms typical page write time, and built-in VCC threshold detection that disables write logic below 1.5V. Acknowledge polling is supported to determine write completion without fixed delay timing.

Key Specifications

Pinout & Package

24AA02UID-I/P is available in 8-lead PDIP (I/P suffix), 8-lead SOIC, and 5-lead SOT-23 packages. The -I/P variant denotes Industrial temperature grade (–40°C to +85°C) in PDIP packaging.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA02UID-I/P, the 24AA02E48-I/P provides standardized EUI-48 formatting for networked devices, while the AT24CM01-SSHM-T trades UID protection guarantees for larger capacity and faster I²C - making the 24AA02UID-I/P optimal for cost-sensitive, safety-critical identity anchoring where UID integrity is non-negotiable.

Availability

24AA02UID-I/P is available at Aetrix Electronics and suitable for secure device authentication, industrial asset tagging, and medical calibration storage requiring stable component supply across extended production lifecycles.

Supply support for 24AA02UID-I/P 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.

The 24AA02UID belongs to Microchip's UID-family of serial EEPROMs, designed specifically to deliver factory-programmed, globally unique identifiers for secure device authentication and traceability in industrial, medical, and IoT applications.

FAQ

What is the exact memory organization of the 24AA02UID-I/P?

The 24AA02UID-I/P contains 256 bytes (2 Kbit) of EEPROM memory, organized as two blocks of 128 × 8-bit. Addresses 0x00–0x7F are user-writable; 0x80–0xFF are write-protected. The 32-bit UID resides at 0xFC–0xFF, manufacturer code at 0xFA (0x29), and device ID at 0xFB (0x41). This layout is fixed and cannot be altered.

How is the unique serial number accessed on the 24AA02UID-I/P?

The 32-bit serial number on the 24AA02UID-I/P is read via standard I²C random read: send control byte 0xA0 (write), then address 0xFC, issue repeated START, send control byte 0xA1 (read), then read four bytes. No special command sequence is required - it behaves as standard EEPROM data at those addresses.

Can the 24AA02UID-I/P be used in 1.8V systems?

Yes, the 24AA02UID-I/P supports VCC from 1.7V to 5.5V. At 1.8V, it operates at 100 kHz I²C speed with full functionality, including UID read, page write, and acknowledge polling. All DC and AC specifications in the datasheet are validated down to 1.7V.

Is there any risk of accidentally overwriting the UID on the 24AA02UID-I/P?

No - the upper half of memory (0x80–0xFF), including the UID at 0xFC–0xFF, is permanently write-protected at the silicon level. Write attempts to these addresses are ignored. Only addresses 0x00–0x7F accept writes, ensuring UID integrity across all operating conditions and power states.

Does the 24AA02UID-I/P require external pull-up resistors on SDA and SCL?

Yes, the 24AA02UID-I/P has open-drain SDA and input-only SCL pins. External pull-up resistors are mandatory: 10 kΩ for 100 kHz operation, 2 kΩ for 400 kHz. Values must be selected based on bus capacitance and target rise time per I²C specification - no internal pull-ups are provided.