Microchip Technology 24AA08-I/ST

Overview

24AA08-I/ST from Microchip Technology Inc. is an 8-Kbit I²C-compatible serial EEPROM organized as four 256 × 8-bit blocks, operating from 1.7V to 5.5V with 400 kHz max clock frequency, 1 µA standby current, and industrial temperature range (–40°C to +85°C). It features hardware write-protection via the WP pin, 16-byte page write buffer, and Schmitt-trigger inputs for noise immunity - deployed in embedded system configuration storage and sensor calibration data retention.

For engineers reviewing the 24AA08-I/ST datasheet, 24AA08-I/ST pinout, 24AA08-I/ST application, or 24AA08-I/ST equivalent, key selection considerations include its 1.7V low-voltage operation, I²C bus timing compliance at 400 kHz (down to 100 kHz below 2.5V), 5 ms max page write time, 1 million endurance cycles, and SOIC-8 package compatibility with legacy board layouts.

Technical Context

The 24AA08-I/ST implements a two-wire I²C interface with open-drain SDA/SCL pins requiring external pull-ups, supports standard-mode (100 kHz) and fast-mode (400 kHz) signaling, and uses internal address pointer logic for sequential, random, and current-address read operations. Its memory architecture includes four independent 256-word blocks selectable via B1/B0 bits in the control byte.

Write protection is implemented via the dedicated WP pin: tied to VSS enables full read/write access; tied to VCC disables all writes while preserving read functionality. The device employs self-timed erase/write cycles with automatic internal timing control and supports acknowledge polling to detect write completion without fixed delay.

Key Specifications

Pinout & Package

24AA08-I/ST is supplied in an 8-lead SOIC (SN) package per Microchip drawing C04-057-SN Rev F, with 3.90 mm body width, 1.27 mm pitch, and surface-mount footprint compatible with JEDEC MS-012AC. Pin 1 is marked by a beveled corner or notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC08B-I/ST, the 24AA08-I/ST enables lower-voltage operation critical for battery-powered designs; compared with 24FC08-I/ST, it trades maximum clock speed for broader legacy I²C peripheral compatibility and proven qualification in industrial deployments.

Availability

24AA08-I/ST is available at Aetrix Electronics and suitable for industrial sensor calibration storage, embedded system configuration memory, and automotive body control module NVM requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 24AA08-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 devices, and memory solutions, headquartered in Chandler, Arizona, with global design, manufacturing, and sales operations.

The 24AA08-I/ST belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power, I²C-based nonvolatile data storage in space-constrained industrial, automotive, and consumer applications.

FAQ

What is the maximum I²C clock frequency supported by the 24AA08-I/ST?

The 24AA08-I/ST supports up to 400 kHz when VCC is 2.5V–5.5V, and 100 kHz when VCC is 1.7V–2.49V. This dual-speed capability ensures interoperability with both standard-mode and fast-mode I²C masters across varying supply conditions. The 24AA08-I/ST does not support 1 MHz operation - that feature is exclusive to the 24FC08 variant.

Does the 24AA08-I/ST require external pull-up resistors on SDA and SCL lines?

Yes, the 24AA08-I/ST has open-drain SDA and SCL pins and requires external pull-up resistors to VCC. Typical values are 10 kΩ for 100 kHz operation and 2 kΩ for 400 kHz. Proper pull-up strength ensures valid logic levels and meets I²C rise-time specifications - critical for reliable communication in the 24AA08-I/ST's target applications.

How does the write-protect (WP) pin function on the 24AA08-I/ST?

When the WP pin of the 24AA08-I/ST is tied to VCC, all write operations (byte and page) are inhibited while read operations remain fully functional. When tied to VSS (or left floating, though not recommended), full read/write access is enabled. This hardware-level protection prevents accidental overwrites during power transitions or firmware errors - a key reliability feature in the 24AA08-I/ST.

What is the memory organization of the 24AA08-I/ST and how is addressing handled?

The 24AA08-I/ST contains 8 Kbits (1024 bytes) organized as four independent 256-word blocks (000–0FF, 100–1FF, 200–2FF, 300–3FF). Block selection is controlled by B1/B0 bits in the I²C control byte; the full 10-bit address is formed by concatenating B1/B0 with the 8-bit word address. This structure enables efficient partitioning of configuration, calibration, and log data within the 24AA08-I/ST.

Is the 24AA08-I/ST qualified for automotive applications?

The 24AA08-I/ST is rated for industrial temperature range (–40°C to +85°C) and is RoHS compliant, but it is not AEC-Q100 qualified. For automotive applications requiring AEC-Q100 certification, Microchip offers the 24LC08B and 24FC08 variants with explicit AEC-Q100 qualification - the 24AA08-I/ST itself lacks this qualification despite sharing the same die family.