Microchip Technology 24AA02-I/ST

Overview

24AA02-I/ST from Microchip Technology is a 2-Kbit I²C-compatible serial EEPROM organized as 256 × 8-bit memory, operating from 1.7V to 5.5V with 400 kHz max clock frequency, 5 ms max page write time, and industrial temperature range (–40°C to +85°C). It features hardware write-protection via the WP pin and is commonly used for storing calibration data, configuration settings, or device identifiers in embedded control modules.

For engineers reviewing the 24AA02-I/ST datasheet, 24AA02-I/ST pinout, 24AA02-I/ST application, or 24AA02-I/ST equivalent, key selection criteria include low-voltage operation down to 1.7V, Schmitt-trigger inputs for noise immunity on I²C buses, 1 µA standby current, 8-byte page write buffer, and factory-programmable capability for secure device identity storage.

Technical Context

The 24AA02-I/ST implements a two-wire I²C interface compliant with standard-mode (100 kHz), fast-mode (400 kHz), and high-speed mode timing when V_CC ≥ 2.5V. Its internal architecture includes an 8-byte page latch, EEPROM array with >1 million endurance cycles, and HV generator for byte/page erase/write operations.

It uses fixed 7-bit client address '1010xxx' with R/W bit, supports current-address, random, and sequential read modes, and incorporates acknowledge polling to detect write completion without fixed delay timing - enabling efficient bus utilization in real-time systems.

Key Specifications

Pinout & Package

24AA02-I/ST is supplied in an 8-lead SOIC package (ST suffix per Microchip's Device Selection Table). Pin 1 is A0 (no internal connection), Pin 2 is A1 (NC), Pin 3 is A2 (NC), Pin 4 is V_SS, Pin 5 is SDA, Pin 6 is SCL, Pin 7 is WP, and Pin 8 is V_CC. All A0–A2 pins may be left floating or tied to V_SS/V_CC without functional impact.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA02-I/ST, the 24LC02B-I/ST sacrifices 1.7V compatibility for marginally lower unit cost, while the AT24C02C-SSHM-T trades pin-level WP compatibility for higher-speed operation - making the 24AA02-I/ST optimal for ultra-low-voltage, drop-in-replacement, and factory-programmed identity storage applications.

Availability

24AA02-I/ST is available at Aetrix Electronics and suitable for industrial sensor nodes, medical diagnostic devices, smart energy meters, and automotive body control modules requiring stable component supply, long-term data retention, and AEC-Q100-compliant nonvolatile memory.

Supply support for 24AA02-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 leading provider of microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24AA02-I/ST belongs to Microchip's 24XX02 family of I²C serial EEPROMs, designed specifically for reliable, low-power, and factory-programmable nonvolatile storage in space-constrained embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the 24AA02-I/ST?

The 24AA02-I/ST supports up to 400 kHz when V_CC is 2.5V or higher. At 1.7V ≤ V_CC < 2.5V, the maximum clock frequency is reduced to 100 kHz to ensure timing margin. This dual-speed capability allows the 24AA02-I/ST to operate reliably across both 1.8V and 3.3V I²C buses without external clock dividers or protocol adaptation.

Does the 24AA02-I/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA02-I/ST requires external pull-up resistors on both SDA and SCL because its I²C interface uses open-drain outputs. Typical values are 10 kΩ for 100 kHz operation and 2 kΩ for 400 kHz. The exact value depends on bus capacitance and desired rise time; insufficient pull-up strength causes timing violations and communication failures in the 24AA02-I/ST.

Can the A0, A1, and A2 pins of the 24AA02-I/ST be left unconnected?

Yes, the A0, A1, and A2 pins of the 24AA02-I/ST are not internally connected and may be left floating, tied to V_SS, or tied to V_CC without affecting functionality. These pins exist for pin compatibility with larger-density EEPROMs but serve no addressing purpose in the 24AA02-I/ST - simplifying schematic design and reducing BOM count.

How does the Write-Protect (WP) pin function on the 24AA02-I/ST?

The WP pin on the 24AA02-I/ST is an active-high hardware lock: when tied to V_CC, it disables all write operations to the entire memory array (addresses 00h–FFh), while read operations remain fully functional. When tied to V_SS, normal read/write access is enabled. This provides deterministic, glitch-immune protection against firmware bugs or unintended writes in the 24AA02-I/ST.

Is the 24AA02-I/ST qualified for automotive applications?

No, the 24AA02-I/ST is rated for industrial temperature range (–40°C to +85°C) and is not AEC-Q100 qualified. For automotive use, Microchip offers the 24AA02E48 variant (with E48 suffix) which meets AEC-Q100 Grade 3 requirements. The 24AA02-I/ST is intended for industrial, medical, and consumer applications where extended temperature or automotive qualification is not required.