Microchip Technology 24AA128-I/MF

Overview

24AA128-I/MF from Microchip Technology Inc. is a 128 Kbit (16K × 8) I²C-compatible serial EEPROM with 1.7V–5.5V single-supply operation, 400 kHz max clock frequency, and industrial temperature range (–40°C to +85°C). It features 64-byte page write buffer, hardware write-protect (WP), Schmitt-trigger inputs, and >1 million erase/write cycles - deployed in embedded sensor calibration, power supply configuration, and industrial control system nonvolatile parameter storage.

For engineers reviewing the 24AA128-I/MF datasheet, 24AA128-I/MF pinout, 24AA128-I/MF application, or 24AA128-I/MF equivalent, this page delivers verified electrical specs, package mapping to 8-lead DFN (MF), I²C timing constraints at 1.7V–5.5V, WP-controlled write inhibition logic, and real-world use cases in firmware-updatable systems requiring >200-year data retention.

Technical Context

The 24AA128-I/MF implements a two-wire I²C slave interface with fixed 7-bit address prefix '1010' and user-configurable A0–A2 chip select bits, enabling 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 supporting byte and page writes with self-timed erase/write cycles.

It uses Schmitt-trigger inputs on SDA/SCL for noise immunity and slope-controlled outputs to suppress ground bounce. Write protection is implemented via dedicated WP pin sampled at Stop condition, and ACK polling is supported to detect write cycle completion without fixed delay timing.

Key Specifications

Pinout & Package

24AA128-I/MF is packaged in an 8-lead DFN (Dual Flat No-lead) with exposed thermal pad, per Microchip drawing C04-057-MF. 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 24AA128-I/MF, the 24LC128-I/MF sacrifices 1.7V operation but maintains identical packaging and command set, while the AT24C128N-10PU-2.7 trades speed and timing predictability for second-source availability in cost-driven consumer designs.

Availability

24AA128-I/MF is available at Aetrix Electronics and suitable for industrial sensor calibration, smart power supply configuration, and medical device usage history logging requiring stable component supply across extended product lifecycles.

Supply support for 24AA128-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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and memory solutions for embedded control applications.

The 24AA128-I/MF belongs to Microchip's 24XX128 family of I²C EEPROMs, designed specifically for reliable, low-power nonvolatile storage in space-constrained industrial and automotive systems.

FAQ

What is the minimum VCC voltage supported by the 24AA128-I/MF?

The 24AA128-I/MF operates down to 1.7V, enabling direct interfacing with ultra-low-power microcontrollers and energy-harvesting circuits. This specification is validated across the full industrial temperature range (–40°C to +85°C) and is distinct from the 2.5V minimum required by the 24LC128 variant. The 24AA128-I/MF maintains full I²C functionality including 400 kHz operation at VCC ≥ 2.5V and 100 kHz at 1.7V ≤ VCC < 2.5V.

How does the WP pin function on the 24AA128-I/MF?

The WP (Write-Protect) pin on the 24AA128-I/MF is a hardware-level control that disables all write operations when pulled high to VCC, while leaving read operations fully functional. It is sampled only at the Stop condition of each write command, meaning toggling WP during an active transfer has no effect. This design allows safe, permanent locking of critical configuration data after system commissioning - a key requirement in medical and industrial safety-critical applications.

Can multiple 24AA128-I/MF devices share the same I²C bus?

Yes, up to eight 24AA128-I/MF devices can be cascaded on a single I²C bus using the A0, A1, and A2 address inputs to configure unique 3-bit slave addresses. Each device's A0–A2 pins must be hardwired to VSS or VCC to establish a static address. The resulting 7-bit slave address format is '1010 A2 A1 A0 R/W', allowing contiguous 1 Mbit address expansion when software maps A0–A2 to higher address bits (A14–A16).

What is the page write buffer size of the 24AA128-I/MF?

The 24AA128-I/MF features a 64-byte page write buffer, allowing up to 64 bytes of data to be loaded into the internal latch before initiating the self-timed write cycle. This significantly improves efficiency over byte-write operations - for example, writing 64 calibration coefficients requires only one I²C transaction instead of 64. Page boundaries align to 64-byte intervals (addresses 0x0000–0x003F, 0x0040–0x007F, etc.), and crossing a boundary causes wraparound within the current page.

Does the 24AA128-I/MF support ACK polling during write cycles?

Yes, the 24AA128-I/MF supports ACK polling to detect write cycle completion: after issuing a Stop condition, the master sends a repeated Start followed by the write control byte (R/W = 0); the device withholds ACK until the internal write is complete. This eliminates fixed timeout delays and maximizes I²C bus utilization. ACK polling is fully compatible with all supported VCC levels and temperature ranges, and is documented in Figure 7-1 of the DS20001191T datasheet.