Microchip Technology 24AA256T-I/MF

Overview

24AA256T-I/MF from Microchip Technology is a 256-Kbit (32K × 8) I²C-compatible serial EEPROM with 1.7V–5.5V single-supply operation, 400 kHz maximum clock frequency, and industrial temperature range (–40°C to +85°C). It features 64-byte page write buffer, hardware write-protection via WP pin, and Schmitt-trigger inputs for noise immunity - deployed in embedded system configuration storage, sensor calibration data retention, and power-meter firmware parameter backup.

For engineers reviewing the 24AA256T-I/MF datasheet, 24AA256T-I/MF pinout, 24AA256T-I/MF application, or 24AA256T-I/MF equivalent, key selection criteria include low-voltage compatibility (down to 1.7V), I²C bus scalability (up to eight devices), page-write timing (≤5 ms), endurance (>1 million cycles), and package-specific pin mapping for MF (8-lead DFN).

Technical Context

The 24AA256T-I/MF implements a two-wire I²C interface with standard and fast-mode timing compliance (100/400 kHz), supporting both byte and page write operations. Its internal address pointer enables sequential reads across the full 256-Kbit memory space, while cascading logic allows up to eight devices on one bus using A0–A2 chip-select bits.

It integrates Schmitt-trigger inputs on SDA/SCL for robust noise suppression, slope-controlled outputs to minimize ground bounce, and a self-timed erase/write cycle with automatic page-buffer management. The WP pin provides hardware-level write protection for the entire memory array (0000h–7FFFh) when tied to VCC.

Key Specifications

Pinout & Package

24AA256T-I/MF is packaged in an 8-lead DFN (Dual Flat No-lead) with exposed thermal pad, footprint code MF per Microchip's packaging specification. Pin 1 is marked by chamfered corner; exposed pad may be connected to VSS or left floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC256-I/MF, the 24AA256T-I/MF enables true 1.8V system integration and broader voltage margin; versus AT24C256-MAHM-T, it delivers certified industrial reliability and Microchip's long-term supply assurance - critical for medical and industrial OEMs.

Availability

24AA256T-I/MF is available at Aetrix Electronics and suitable for smart metering, industrial sensor nodes, automotive body control units, and medical diagnostic devices requiring stable component supply across multi-year production cycles.

Supply support for 24AA256T-I/MF 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 microcontroller, analog, FPGA, and memory solutions, serving automotive, industrial, communications, and consumer markets with vertically integrated silicon and development tools.

The 24AA256T-I/MF belongs to Microchip's 24XX256 family of I²C EEPROMs, designed specifically for low-power, high-reliability nonvolatile data storage in embedded systems where voltage flexibility, noise immunity, and long-term data integrity are mandatory.

FAQ

What is the minimum operating voltage for the 24AA256T-I/MF?

The 24AA256T-I/MF operates down to 1.7V across its full industrial temperature range (–40°C to +85°C), enabling direct interface with 1.8V logic families and battery-powered systems without level translation. This is a key differentiator from the 24LC256 variant, which requires ≥2.5V.

Does the 24AA256T-I/MF support page write operations, and what is the maximum buffer size?

Yes, the 24AA256T-I/MF supports page write operations with a 64-byte internal buffer. A single I²C transaction can load up to 64 bytes into the buffer, and the internal write cycle begins upon receipt of the Stop condition - reducing bus overhead by up to 64× compared to byte-write mode.

How does the WP pin function on the 24AA256T-I/MF?

The WP (Write-Protect) pin on the 24AA256T-I/MF is a hardware-level enable/disable control: when tied to VCC, all write operations (byte and page) are inhibited while read operations remain fully functional. The pin state is sampled at the Stop bit of each command, providing deterministic protection against spurious writes during power transitions.

What package type is used for the 24AA256T-I/MF, and what are its key mechanical features?

The 24AA256T-I/MF uses an 8-lead DFN (Dual Flat No-lead) package with Microchip's MF footprint designation. It features an exposed thermal pad (optional VSS connection), 0.5 mm lead pitch, and JEDEC-standard marking including part number "24AA256", temperature grade "I", and date code - compliant with automated SMT assembly.

Can multiple 24AA256T-I/MF devices share the same I²C bus, and how is addressing managed?

Yes, up to eight 24AA256T-I/MF devices can share one I²C bus using hard-wired A0, A1, and A2 pins to configure unique 3-bit chip addresses (1010xxx). Each device responds only to commands matching its physical address, enabling scalable memory expansion up to 2 Mbit without additional address decoding logic.