Microchip Technology 24AA128-I/MS

Overview

24AA128-I/MS from Microchip Technology is a 128 Kbit (16K × 8) I²C-compatible serial EEPROM with industrial temperature range (–40°C to +85°C), 1.7V–5.5V supply operation, and 400 kHz maximum clock frequency. It features 64-byte page write buffering, hardware write-protection via the WP pin, and Schmitt-trigger inputs for noise immunity. It is used in embedded systems for nonvolatile storage of calibration data, configuration settings, and firmware parameters.

For engineers reviewing the 24AA128-I/MS datasheet, 24AA128-I/MS pinout, 24AA128-I/MS application, or 24AA128-I/MS equivalent, this page delivers verified electrical specs, package mapping to MSOP-8, I²C timing constraints at 1.7–5.5V, endurance (1M cycles), and real-world use cases in sensor modules and power management units.

Technical Context

The 24AA128-I/MS implements a two-wire I²C interface with slave addressing using A0–A2 pins (A0 and A1 are no-connects in MSOP-8 package), supporting up to eight devices on one bus. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and memory control logic that enforces self-timed erase/write cycles.

It supports byte and page write modes, current address/random/sequential reads, and ACK polling for write-cycle completion detection. The device uses open-drain SDA/SCL with external pull-ups and incorporates slope control and Schmitt-trigger inputs to suppress ground bounce and noise spikes.

Key Specifications

Pinout & Package

24AA128-I/MS is packaged in an 8-lead MSOP (Mini Small Outline Package) with 0.65 mm lead pitch and exposed pad (optional VSS connection). Pin 1 is marked by a beveled corner; A0 and A1 are not connected internally in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC128-I/MS and AT24C128N-10PU-2.7, the 24AA128-I/MS uniquely supports 1.7V operation and AEC-Q100 qualification in MSOP-8, making it the sole choice for automotive-grade, low-voltage, surface-mount EEPROM deployments.

Availability

24AA128-I/MS is available at Aetrix Electronics and suitable for smart sensor nodes, industrial PLC modules, medical diagnostic devices, and automotive body control units requiring stable component supply across extended product lifecycles.

Supply support for 24AA128-I/MS 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 manufacturing and support infrastructure.

The 24AA128 belongs to Microchip's 24XX128 family of I²C EEPROMs, designed specifically for robust, low-power nonvolatile data storage in industrial, automotive, and medical applications demanding wide voltage range and long-term reliability.

FAQ

What is the operating voltage range of the 24AA128-I/MS?

The 24AA128-I/MS operates from 1.7V to 5.5V, enabling direct interface with 1.8V, 3.3V, and 5V systems without level-shifting circuitry. This wide range supports battery-powered and mixed-voltage embedded designs where supply rails may vary across subsystems. The 24AA128-I/MS maintains full I²C functionality and timing compliance across this entire span.

How many devices can be connected on the same I²C bus using the 24AA128-I/MS?

Up to two 24AA128-I/MS devices can share one I²C bus due to the MSOP-8 package having A0 and A1 as no-connects - only A2 is functional for slave address selection. This yields two possible addresses (1010001b and 1010011b), limiting cascading versus SOIC/TSSOP variants which support eight devices via A0–A2.

Does the 24AA128-I/MS support page write operations, and what is the buffer size?

Yes, the 24AA128-I/MS supports page write with a 64-byte internal buffer. This allows up to 64 bytes to be loaded into the latch before initiating the self-timed write cycle, reducing I²C transaction overhead and improving throughput for bulk data storage. The 24AA128-I/MS enforces physical page boundaries (64-byte alignment), so crossing boundaries causes wraparound.

What is the endurance and data retention specification for the 24AA128-I/MS?

The 24AA128-I/MS guarantees 1,000,000 erase/write cycles and greater than 200 years of data retention at +85°C. These specifications are validated per JEDEC standards and ensure long-term reliability in applications such as energy meters and medical devices where infrequent but critical writes occur over decades of service life. The 24AA128-I/MS achieves this via optimized oxide thickness and charge-trapping mechanisms.

Is the 24AA128-I/MS qualified for automotive applications?

Yes, the 24AA128-I/MS is AEC-Q100 qualified (Grade 2: –40°C to +105°C), making it suitable for automotive body electronics including seat memory, lighting control, and door modules. Its qualification covers stress testing for temperature cycling, humidity, ESD, and mechanical shock - confirming robustness in vehicular environments. The 24AA128-I/MS meets these requirements while retaining full industrial temperature grade (–40°C to +85°C) compatibility.