Microchip Technology 24FC128-I/MF

Overview

24FC128-I/MF from Microchip Technology Inc. is a 128 Kbit (16K × 8) I²C-compatible serial EEPROM with 1 MHz maximum clock frequency, 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 24FC128-I/MF datasheet, 24FC128-I/MF pinout, 24FC128-I/MF application, or 24FC128-I/MF equivalent, key selection criteria include its 1 MHz I²C speed at V_CC ≥ 2.5V, 5 ms max page write time, 1 µA standby current, and MF-package (8-lead TDFN) footprint compatibility with space-constrained PCB layouts.

Technical Context

The 24FC128-I/MF implements a two-wire I²C slave interface with fixed 4-bit control code (1010b) and user-configurable A2/A1/A0 address bits for multi-device bus addressing. Its internal architecture includes a 64-byte page latch, HV generator for EEPROM programming, and memory control logic supporting byte and page write modes 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, enabling hardware-level array lock without software intervention.

Key Specifications

Pinout & Package

24FC128-I/MF is packaged in an 8-lead TDFN (Thin Dual Flat No-lead) package, 2 mm × 3 mm body, 0.5 mm pitch, with exposed thermal pad (optional V_SS connection). Pinout matches standard 8-lead SOIC/TSSOP but with bottom-side terminations.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24AA128-I/MF and AT24C128-MAHM-T, the 24FC128-I/MF delivers 2.5× higher I²C throughput and extended 1.7V operation-critical for energy-harvesting and battery-backed systems where every millisecond and millivolt matters.

Availability

24FC128-I/MF is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration backup, and automotive body control modules requiring stable component supply across extended product lifecycles.

Supply support for 24FC128-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, FPGA, and memory solutions, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.

The 24FC128 belongs to Microchip's 24XX128 family of serial EEPROMs, designed specifically for low-power, multi-voltage I²C systems requiring robust data retention, fast write capability, and hardware write protection in space-constrained designs.

FAQ

What is the maximum I²C clock frequency supported by the 24FC128-I/MF?

The 24FC128-I/MF supports up to 1 MHz I²C clock frequency when V_CC is ≥2.5V. At 1.7V ≤ V_CC < 2.5V, maximum frequency drops to 400 kHz. This dual-speed capability allows design flexibility across 1.8V, 3.3V, and 5V systems while maintaining backward compatibility with legacy 400 kHz controllers. The 24FC128-I/MF datasheet specifies timing parameters including THIGH, TLOW, and TSU:DAT explicitly for both ranges.

Does the 24FC128-I/MF require external pull-up resistors on SDA and SCL lines?

Yes, the 24FC128-I/MF requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. 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 suffices. These values ensure rise times meet AC specifications (TR ≤ 300 ns at 1 MHz) while limiting bus current. The 24FC128-I/MF itself does not integrate pull-ups.

How does the hardware write-protect (WP) pin function on the 24FC128-I/MF?

The WP pin on the 24FC128-I/MF is sampled at the Stop condition of each write command. When tied to V_CC, it disables all write operations-including byte, page, and erase-while permitting unlimited reads. When tied to V_SS, writes are enabled. WP state cannot be changed mid-cycle; toggling after Stop has no effect. This hardware lock prevents accidental overwrites during power transitions or firmware errors, making the 24FC128-I/MF suitable for safety-critical parameter storage.

What package type does the 24FC128-I/MF use, and what are its key mechanical features?

The 24FC128-I/MF uses the MF package: an 8-lead TDFN (Thin Dual Flat No-lead) measuring 2 mm × 3 mm with 0.5 mm pitch and an exposed thermal pad. Unlike SOIC or TSSOP, TDFN places all terminals on the bottom surface, enabling ultra-compact PCB layouts and improved thermal performance. The exposed pad may be connected to V_SS for enhanced heat dissipation or left floating. This package is RoHS-compliant and qualified for industrial temperature operation.

Can multiple 24FC128-I/MF devices share the same I²C bus, and how is addressing managed?

Yes, up to eight 24FC128-I/MF devices can share one I²C bus using hardware address pins A2, A1, and A0. Each device's 7-bit slave address is formed by the fixed prefix '1010' plus the 3-bit value set by these pins (e.g., A2=0, A1=1, A0=0 yields address 0x54). All three pins must be hardwired to V_SS or V_CC; floating connections are invalid. This enables contiguous 1 Mbit address expansion across devices, though sequential reads cannot cross device boundaries.