Microchip Technology 24FC128T-I/MF

Overview

24FC128T-I/MF from Microchip Technology Inc. is a 128 Kbit (16K × 8) I²C-compatible serial EEPROM with 1 MHz maximum clock frequency at V_CC ≥ 2.5V, 1.7V–5.5V supply range, and industrial temperature rating (–40°C to +85°C). It features 64-byte page write buffer, hardware write-protect (WP), Schmitt-trigger inputs, and supports up to eight devices on one bus. Used in embedded system configuration storage, sensor calibration data retention, and firmware parameter backup.

For engineers reviewing the 24FC128T-I/MF datasheet, 24FC128T-I/MF pinout, 24FC128T-I/MF application, or 24FC128T-I/MF equivalent, key selection criteria include its 1 MHz I²C speed at low voltage, 1 µA standby current, 5 ms max page write time, and compatibility with microcontroller-based systems requiring nonvolatile memory with robust noise immunity and cascading capability.

Technical Context

The 24FC128T-I/MF implements a two-wire I²C slave interface with fixed 4-bit control code (1010b) and user-configurable A2/A1/A0 address bits, enabling up to eight devices on a shared bus. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and memory control logic supporting byte and page write modes.

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

Key Specifications

Pinout & Package

24FC128T-I/MF is packaged in an 8-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, JEDEC MO-153 compliant, body size 4.4 mm × 3.0 mm × 1.2 mm. Pin 1 is marked with a dot or beveled corner; pin numbering follows standard counterclockwise sequence from top-left when viewed from top.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA128T-I/MF and AT24C128-10PU-2.7, the 24FC128T-I/MF delivers higher bandwidth, broader supply compatibility, and automotive-grade reliability-making it optimal for next-generation industrial and automotive electronics where speed, voltage flexibility, and qualification matter.

Availability

24FC128T-I/MF is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration backup, and automotive body control module settings requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 24FC128T-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 microcontrollers, analog components, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The 24FC128T-I/MF belongs to Microchip's 24XX128 family of I²C EEPROMs, designed specifically for low-power, high-reliability nonvolatile data storage in space-constrained embedded systems requiring robust noise immunity and flexible voltage operation.

FAQ

What is the maximum I²C clock frequency supported by the 24FC128T-I/MF?

The 24FC128T-I/MF supports up to 1 MHz I²C clock frequency when V_CC is 2.5V or higher. At supply voltages between 1.7V and 2.5V, the maximum clock frequency is limited to 400 kHz. This dual-speed capability allows seamless integration into both legacy 400 kHz systems and newer high-throughput designs without changing the 24FC128T-I/MF part number.

Does the 24FC128T-I/MF require external pull-up resistors on SDA and SCL lines?

Yes, the 24FC128T-I/MF requires external pull-up resistors on both SDA and SCL lines because these pins are open-drain. For 1 MHz operation, a 2 kΩ pull-up to V_CC is recommended; for 400 kHz, 2.2 kΩ is typical; and for 100 kHz, 10 kΩ is sufficient. Proper pull-up strength ensures valid logic levels and meets rise-time specifications per I²C standard.

How does hardware write-protection work on the 24FC128T-I/MF?

The WP pin on the 24FC128T-I/MF provides hardware-level write protection: when tied to V_CC, all write operations (byte and page) are inhibited while read operations remain fully functional. The pin is sampled only at the Stop condition of each write command, making it immune to transient noise or mid-cycle toggling-ensuring deterministic protection behavior.

Can multiple 24FC128T-I/MF devices share the same I²C bus?

Yes, up to eight 24FC128T-I/MF devices can share a single I²C bus using the A2, A1, and A0 address pins to configure unique 3-bit chip addresses. Each device must have a distinct combination of logic levels on these pins (VSS or VCC), enabling individual addressing without bus contention or additional hardware.

What is the page write buffer size of the 24FC128T-I/MF?

The 24FC128T-I/MF has a 64-byte page write buffer, allowing up to 64 bytes to be loaded into the internal latch before initiating the self-timed write cycle. This reduces host MCU overhead and improves effective write throughput compared to byte-by-byte programming, especially in applications requiring frequent small-block updates.